From 8e15dc2072220828ce9a1c8a98be6610180b72a2 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Tue, 6 Dec 2016 01:37:34 +0100
Subject: [PATCH 01/31] Watch test files (so they retrigger webpack)

This will not process them for now...
---
 .../react-dev-utils/WatchTestFilesPlugin.js   | 39 +++++++++++++++++++
 packages/react-dev-utils/package.json         |  2 +
 .../config/webpack.config.dev.js              | 10 ++++-
 3 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 packages/react-dev-utils/WatchTestFilesPlugin.js

diff --git a/packages/react-dev-utils/WatchTestFilesPlugin.js b/packages/react-dev-utils/WatchTestFilesPlugin.js
new file mode 100644
index 00000000000..039a66501e6
--- /dev/null
+++ b/packages/react-dev-utils/WatchTestFilesPlugin.js
@@ -0,0 +1,39 @@
+var glob = require('glob');
+var path = require('path');
+
+function computeGlob(pattern, options) {
+  return new Promise((resolve, reject) => {
+    glob(pattern, options || {}, (err, matches) => {
+      if (err) {
+        return reject(err);
+      }
+      resolve(matches);
+    });
+  });
+}
+
+function WatchTestFilesPlugin(testGlobs) {
+  this.testGlobs = testGlobs || [];
+}
+
+WatchTestFilesPlugin.prototype.apply = function(compiler) {
+  compiler.plugin('emit', (compilation, callback) => {
+    console.log()
+    Promise.all(this.testGlobs.map(globPattern =>
+      computeGlob(globPattern, {
+        cwd: compiler.options.context,
+        ignore: 'node_modules/**',
+      })
+    ))
+    .then(globLists => [].concat.apply([], globLists))
+    .then(testFiles => {
+      testFiles.forEach(testFile => {
+        compilation.fileDependencies.push(path.join(compiler.options.context, testFile));
+      });
+    })
+    .then(callback)
+    .catch(console.error);
+  });
+};
+
+module.exports = WatchTestFilesPlugin;
diff --git a/packages/react-dev-utils/package.json b/packages/react-dev-utils/package.json
index 5d8051a8830..9811f261f06 100644
--- a/packages/react-dev-utils/package.json
+++ b/packages/react-dev-utils/package.json
@@ -20,12 +20,14 @@
     "openBrowser.js",
     "prompt.js",
     "WatchMissingNodeModulesPlugin.js",
+    "WatchTestFilesPlugin.js",
     "webpackHotDevClient.js"
   ],
   "dependencies": {
     "ansi-html": "0.0.5",
     "chalk": "1.1.3",
     "escape-string-regexp": "1.0.5",
+    "glob": "^7.1.1",
     "html-entities": "1.2.0",
     "opn": "4.0.2",
     "sockjs-client": "1.0.3",
diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index 96fd632b795..7677b8b5011 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -15,6 +15,7 @@ var HtmlWebpackPlugin = require('html-webpack-plugin');
 var CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
 var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
 var WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
+var WatchTestFilesPlugin = require('react-dev-utils/WatchTestFilesPlugin');
 var getClientEnvironment = require('./env');
 var paths = require('./paths');
 
@@ -226,7 +227,14 @@ module.exports = {
     // to restart the development server for Webpack to discover it. This plugin
     // makes the discovery automatic so you don't have to restart.
     // See https://github.com/facebookincubator/create-react-app/issues/186
-    new WatchMissingNodeModulesPlugin(paths.appNodeModules)
+    new WatchMissingNodeModulesPlugin(paths.appNodeModules),
+    // Tests won't have any linting unless they go through webpack.
+    // This plugin makes webpack aware of them without emitting them.
+    // See https://github.com/facebookincubator/create-react-app/issues/1169
+    new WatchTestFilesPlugin([
+      '**/__tests__/**',
+      '**/*.test.js',
+    ]),
   ],
   // Some libraries import Node modules but don't use them in the browser.
   // Tell Webpack to provide empty mocks for them so importing them works.

From 19f86d155d465235077a1342f7cb3ffb4fecd89b Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Tue, 6 Dec 2016 02:23:54 +0100
Subject: [PATCH 02/31] Structure where to put upcoming module addition

---
 .../react-dev-utils/WatchTestFilesPlugin.js   | 43 ++++++++++++-------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/packages/react-dev-utils/WatchTestFilesPlugin.js b/packages/react-dev-utils/WatchTestFilesPlugin.js
index 039a66501e6..9ce5c41d185 100644
--- a/packages/react-dev-utils/WatchTestFilesPlugin.js
+++ b/packages/react-dev-utils/WatchTestFilesPlugin.js
@@ -12,27 +12,40 @@ function computeGlob(pattern, options) {
   });
 }
 
+function getGlobs(patterns, cwd) {
+  return Promise.all(patterns.map(globPattern =>
+    computeGlob(globPattern, {
+      cwd: cwd,
+      ignore: 'node_modules/**',
+    })
+  ))
+  .then(globLists => [].concat.apply([], globLists))
+}
+
 function WatchTestFilesPlugin(testGlobs) {
   this.testGlobs = testGlobs || [];
 }
 
 WatchTestFilesPlugin.prototype.apply = function(compiler) {
-  compiler.plugin('emit', (compilation, callback) => {
-    console.log()
-    Promise.all(this.testGlobs.map(globPattern =>
-      computeGlob(globPattern, {
-        cwd: compiler.options.context,
-        ignore: 'node_modules/**',
-      })
-    ))
-    .then(globLists => [].concat.apply([], globLists))
-    .then(testFiles => {
-      testFiles.forEach(testFile => {
-        compilation.fileDependencies.push(path.join(compiler.options.context, testFile));
-      });
+  var testFiles = [];
+  compiler.plugin('make', (compilation, callback) => {
+    getGlobs(this.testGlobs, compiler.options.context)
+    .then(foundFiles => {
+      testFiles = foundFiles;
+      return Promise.all(
+        testFiles.map(filename => new Promise((resolve, reject) => {
+          // TODO: add to modules
+          resolve(filename);
+        }))
+      )
     })
-    .then(callback)
-    .catch(console.error);
+    .then(callback);
+  });
+  compiler.plugin('emit', (compilation, callback) => {
+    testFiles.forEach(testFile => {
+      compilation.fileDependencies.push(path.join(compiler.options.context, testFile));
+    });
+    callback();
   });
 };
 

From e0d373b213faaa3961e7c29d6e430caeca8339b4 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Thu, 8 Dec 2016 18:08:50 +0100
Subject: [PATCH 03/31] Create some sub compilations for tests

This result will not be used for serving the pages but will be used for tracking lint/type errors in those files
---
 .../react-dev-utils/WatchTestFilesPlugin.js   | 60 +++++++++++++------
 packages/react-dev-utils/package.json         |  6 ++
 2 files changed, 48 insertions(+), 18 deletions(-)

diff --git a/packages/react-dev-utils/WatchTestFilesPlugin.js b/packages/react-dev-utils/WatchTestFilesPlugin.js
index 9ce5c41d185..b7b25fd4713 100644
--- a/packages/react-dev-utils/WatchTestFilesPlugin.js
+++ b/packages/react-dev-utils/WatchTestFilesPlugin.js
@@ -1,5 +1,7 @@
 var glob = require('glob');
 var path = require('path');
+var os = require('os');
+var SingleEntryPlugin = require('webpack/lib/SingleEntryPlugin');
 
 function computeGlob(pattern, options) {
   return new Promise((resolve, reject) => {
@@ -26,26 +28,48 @@ function WatchTestFilesPlugin(testGlobs) {
   this.testGlobs = testGlobs || [];
 }
 
-WatchTestFilesPlugin.prototype.apply = function(compiler) {
-  var testFiles = [];
-  compiler.plugin('make', (compilation, callback) => {
-    getGlobs(this.testGlobs, compiler.options.context)
-    .then(foundFiles => {
-      testFiles = foundFiles;
-      return Promise.all(
-        testFiles.map(filename => new Promise((resolve, reject) => {
-          // TODO: add to modules
-          resolve(filename);
-        }))
-      )
-    })
-    .then(callback);
+function compileTestFile(compiler, compilation, context, testFile) {
+  var outputOptions = {
+    filename: path.join(os.tmpdir(), '__compiledTests__', testFile),
+    publicPath: compilation.outputOptions.publicPath,
+  };
+  var compilerName = "WatchTestFiles compilation for " + testFile;
+  var childCompiler = compilation.createChildCompiler(compilerName, outputOptions);
+  childCompiler.context = context;
+  childCompiler.apply(
+    new SingleEntryPlugin(context, path.join(compiler.options.context, testFile))
+  );
+  return new Promise((resolve, reject) => {
+    childCompiler.runAsChild((err, entries, childCompilation) => {
+      if (err) {
+        return reject(err);
+      }
+      resolve({
+        errors: childCompilation.errors,
+        warnings: childCompilation.warnings,
+      });
+    });
   });
+}
+
+WatchTestFilesPlugin.prototype.apply = function(compiler) {
   compiler.plugin('emit', (compilation, callback) => {
-    testFiles.forEach(testFile => {
-      compilation.fileDependencies.push(path.join(compiler.options.context, testFile));
-    });
-    callback();
+    getGlobs(this.testGlobs, compiler.options.context)
+    .then(foundFiles => Promise.all(
+      foundFiles.map(filename => {
+        // Add them to the list of watched files (for auto-reloading)
+        compilation.fileDependencies.push(path.join(compiler.options.context, filename));
+        // Create and run a sub-compiler for the file to send it through the loaders
+        return compileTestFile(compiler, compilation, compiler.context, filename)
+      })
+    ))
+    .then((results) => {
+      var errors = results.reduce((list, res) => list.concat(res.errors || []), []);
+      var warnings = results.reduce((list, res) => list.concat(res.warnings || []), []);
+      compilation.errors = compilation.errors.concat(errors);
+      compilation.warnings = compilation.warnings.concat(warnings);
+      callback();
+    }, callback);
   });
 };
 
diff --git a/packages/react-dev-utils/package.json b/packages/react-dev-utils/package.json
index 9811f261f06..fce93d7f170 100644
--- a/packages/react-dev-utils/package.json
+++ b/packages/react-dev-utils/package.json
@@ -32,5 +32,11 @@
     "opn": "4.0.2",
     "sockjs-client": "1.0.3",
     "strip-ansi": "3.0.1"
+  },
+  "devDependencies": {
+    "webpack": "1.14.0"
+  },
+  "peerDependencies": {
+    "webpack": "1.14.0"
   }
 }

From e332fe5101e8dff0de7e4385b034ada8fd7d1afd Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 19:23:23 +0100
Subject: [PATCH 04/31] Setup a plugin to run a flow checking lifecycle

This will only run if a @flow annotation is seen:
- At the first @flow file found:
  - Write a .flowconfig if none exists
  - [Not done yet] Run flow-typed install
  - [Not done yet] Start a flow instance
- When a file with an @flow comment changes during a compilation:
  - [Not done yet] Run a flow check
  - If there are some errors in flow:
    - If CI: output as an error
    - If not CI: output as a warning
---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 83 +++++++++++++++++++
 packages/react-dev-utils/package.json         |  1 +
 .../config/webpack.config.dev.js              | 13 ++-
 3 files changed, 96 insertions(+), 1 deletion(-)
 create mode 100644 packages/react-dev-utils/FlowTypecheckPlugin.js

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
new file mode 100644
index 00000000000..ff4d8bd3500
--- /dev/null
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -0,0 +1,83 @@
+var fs = require('fs');
+var path = require('path');
+
+function FlowTypecheckPlugin(options) {
+  this.options = options || {};
+  // If flow is globally present in the project, this will stay across compilations
+  this._flowInitialized = false;
+  // If flow should run in a current compilation
+  this._flowShouldRun = false;
+  // Stores the last flow output
+  this._flowOutput = "";
+}
+
+FlowTypecheckPlugin.prototype.apply = function(compiler) {
+  compiler.plugin('compilation', function(compilation, params) {
+    // Detect the presence of flow and initialize it
+    compilation.plugin('normal-module-loader', function(loaderContext, module) {
+      // We're only checking the presence of flow in non-node_modules
+      // (some dependencies may keep their flow comments, we don't want to match them)
+      if (module.resource.indexOf("node_modules") < 0) {
+        // We use webpack's cached FileSystem to avoid slowing down compilation
+        loaderContext.fs.readFile(module.resource, function(err, data) {
+          if (data && data.toString().indexOf('@flow') >= 0) {
+            if (!this._flowInitialized) {
+              this._initializeFlow(compiler.options.context);
+              this._flowInitialized = true;
+            }
+            this._flowShouldRun = true;
+          }
+        }.bind(this));
+      }
+    }.bind(this))
+  }.bind(this));
+
+  // While emitting run a flow check if flow has been detected
+  compiler.plugin('emit', function(compilation, callback) {
+    // Only if a file with @ flow has been changed
+    if (this._flowShouldRun) {
+      this._flowOutput = this._flowCheck();
+      this._flowShouldRun = false;
+    }
+    if (this._flowOutput.length > 0) {
+      // In a CI, we wish to get flow breaking the build so we write errors here
+      if (process.env.CI) {
+        compilation.errors.push(this._flowOutput);
+      } else {
+        compilation.warnings.push(this._flowOutput);
+      }
+    }
+    callback();
+  }.bind(this));
+};
+
+// This initializer will run once per webpack run (runs once across all compilations)
+FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath) {
+  const flowconfigPath = path.join(projectPath, '.flowconfig');
+  fs.exists(flowconfigPath, function(exists) {
+    if (!exists) {
+      fs.writeFile(flowconfigPath, (this.options.flowconfig || []).join('\n'));
+    }
+  }.bind(this));
+  // TODO: run flow-typed
+  // TODO: start a flow instance
+};
+
+// This check will run each time a compilation sees a file with @ flow change
+FlowTypecheckPlugin.prototype._flowCheck = function() {
+  // TODO: run a single flow check
+  return `
+src/App.js:11
+ 11: f("abc");
+     ^^^^^^^^ function call
+ 11: f("abc");
+       ^^^^^ string. This type is incompatible with
+  7: function f(x: number) {
+                   ^^^^^^ number
+
+
+Found 1 error
+  `;
+};
+
+module.exports = FlowTypecheckPlugin;
diff --git a/packages/react-dev-utils/package.json b/packages/react-dev-utils/package.json
index 5d8051a8830..0befc5d4dc4 100644
--- a/packages/react-dev-utils/package.json
+++ b/packages/react-dev-utils/package.json
@@ -12,6 +12,7 @@
   },
   "files": [
     "clearConsole.js",
+    "FlowTypecheckPlugin.js",
     "checkRequiredFiles.js",
     "formatWebpackMessages.js",
     "getProcessForPort.js",
diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index 96fd632b795..97fdb25913d 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -15,6 +15,7 @@ var HtmlWebpackPlugin = require('html-webpack-plugin');
 var CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
 var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
 var WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
+var FlowTypecheckPlugin = require('react-dev-utils/FlowTypecheckPlugin');
 var getClientEnvironment = require('./env');
 var paths = require('./paths');
 
@@ -226,7 +227,17 @@ module.exports = {
     // to restart the development server for Webpack to discover it. This plugin
     // makes the discovery automatic so you don't have to restart.
     // See https://github.com/facebookincubator/create-react-app/issues/186
-    new WatchMissingNodeModulesPlugin(paths.appNodeModules)
+    new WatchMissingNodeModulesPlugin(paths.appNodeModules),
+    // Trigger some typechecking if a file matches with an @ flow comment
+    new FlowTypecheckPlugin({
+      flowconfig: [
+        '[ignore]',
+        '<PROJECT_ROOT>/node_modules/fbjs/.*',
+        '',
+        '[libs]',
+        './flow-typed'
+      ]
+    })
   ],
   // Some libraries import Node modules but don't use them in the browser.
   // Tell Webpack to provide empty mocks for them so importing them works.

From eddd11b6ba03803b579ab1901db2cb61dffff3a7 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 19:35:16 +0100
Subject: [PATCH 05/31] Make flow fail on CI builds

We don't need complex logic with process.env on the plugin side, we let the build script figure this out!
---
 packages/react-dev-utils/FlowTypecheckPlugin.js      | 8 ++------
 packages/react-scripts/config/webpack.config.prod.js | 5 ++++-
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index ff4d8bd3500..e815d7b14ed 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -39,13 +39,9 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
       this._flowOutput = this._flowCheck();
       this._flowShouldRun = false;
     }
+    // Output a warning if flow failed
     if (this._flowOutput.length > 0) {
-      // In a CI, we wish to get flow breaking the build so we write errors here
-      if (process.env.CI) {
-        compilation.errors.push(this._flowOutput);
-      } else {
-        compilation.warnings.push(this._flowOutput);
-      }
+      compilation.warnings.push(this._flowOutput);
     }
     callback();
   }.bind(this));
diff --git a/packages/react-scripts/config/webpack.config.prod.js b/packages/react-scripts/config/webpack.config.prod.js
index 71509658eb7..bf98cfac6a7 100644
--- a/packages/react-scripts/config/webpack.config.prod.js
+++ b/packages/react-scripts/config/webpack.config.prod.js
@@ -16,6 +16,7 @@ var ExtractTextPlugin = require('extract-text-webpack-plugin');
 var ManifestPlugin = require('webpack-manifest-plugin');
 var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
 var SubresourceIntegrityPlugin = require('webpack-subresource-integrity');
+var FlowTypecheckPlugin = require('react-dev-utils/FlowTypecheckPlugin');
 var url = require('url');
 var paths = require('./paths');
 var getClientEnvironment = require('./env');
@@ -277,7 +278,9 @@ module.exports = {
     // Generate and inject subresources hashes in the final `index.html`.
     new SubresourceIntegrityPlugin({
       hashFuncNames: ['sha256', 'sha384']
-    })
+    }),
+    // Run Flow only if we see some @ flow annotations, will error on CI
+    new FlowTypecheckPlugin({})
   ],
   // Some libraries import Node modules but don't use them in the browser.
   // Tell Webpack to provide empty mocks for them so importing them works.

From 097d7d97c74e0228023fe10c0d1e479a3032e566 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 22:05:36 +0100
Subject: [PATCH 06/31] Run flow as a server and check with status

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 80 ++++++++++++++-----
 packages/react-dev-utils/package.json         |  1 +
 .../config/webpack.config.dev.js              |  3 +-
 3 files changed, 62 insertions(+), 22 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index e815d7b14ed..6dc631aa7e9 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -1,5 +1,7 @@
 var fs = require('fs');
 var path = require('path');
+var flowBinPath = require('flow-bin');
+var childProcess = require('child_process');
 
 function FlowTypecheckPlugin(options) {
   this.options = options || {};
@@ -9,6 +11,8 @@ function FlowTypecheckPlugin(options) {
   this._flowShouldRun = false;
   // Stores the last flow output
   this._flowOutput = "";
+  // Flow server process
+  this._flowServer = null;
 }
 
 FlowTypecheckPlugin.prototype.apply = function(compiler) {
@@ -36,14 +40,27 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
   compiler.plugin('emit', function(compilation, callback) {
     // Only if a file with @ flow has been changed
     if (this._flowShouldRun) {
-      this._flowOutput = this._flowCheck();
       this._flowShouldRun = false;
+      var version = this.options.flowVersion || 'latest';
+      this._flowCheck(compiler.options.context, version, function(err, flowOutput) {
+        if (err) {
+          compilation.errors.push(err.message);
+          return callback();
+        }
+        this._flowOutput = flowOutput;
+        // Output a warning if flow failed
+        if (this._flowOutput.indexOf('No errors!') < 0) {
+          compilation.warnings.push(this._flowOutput);
+        }
+        callback();
+      }.bind(this));
+    } else {
+      // Output a warning if flow failed in a previous run
+      if (this._flowOutput.length > 0 && this._flowOutput.indexOf('No errors!') < 0) {
+        compilation.warnings.push(this._flowOutput);
+      }
+      callback();
     }
-    // Output a warning if flow failed
-    if (this._flowOutput.length > 0) {
-      compilation.warnings.push(this._flowOutput);
-    }
-    callback();
   }.bind(this));
 };
 
@@ -56,24 +73,45 @@ FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath) {
     }
   }.bind(this));
   // TODO: run flow-typed
-  // TODO: start a flow instance
+  this._flowServer = childProcess.spawn(
+    flowBinPath,
+    ['server'],
+    { cwd: projectPath }
+  );
 };
 
 // This check will run each time a compilation sees a file with @ flow change
-FlowTypecheckPlugin.prototype._flowCheck = function() {
-  // TODO: run a single flow check
-  return `
-src/App.js:11
- 11: f("abc");
-     ^^^^^^^^ function call
- 11: f("abc");
-       ^^^^^ string. This type is incompatible with
-  7: function f(x: number) {
-                   ^^^^^^ number
-
-
-Found 1 error
-  `;
+FlowTypecheckPlugin.prototype._flowCheck = function(projectPath, flowVersion, cb) {
+  var flowOutput = "";
+  var flowErrOutput = "";
+  var statusCheck = childProcess.spawn(
+    flowBinPath,
+    ['status', '--no-auto-start', '--color=always'],
+    { cwd: projectPath }
+  );
+  statusCheck.stdout.on('data', function(chunk) {
+    flowOutput += chunk.toString();
+  });
+  statusCheck.stderr.on('data', function(chunk) {
+    flowErrOutput += chunk.toString();
+  });
+  statusCheck.on('close', function() {
+    if (flowErrOutput.length > 0) {
+      if (flowErrOutput.indexOf("There is no Flow server running") >= 0) {
+        return cb(new Error(
+          'flow server: unexpectedly died.\n' +
+          'This is likely due to a version mismatch between a global flow ' +
+          'server (that you or your IDE may try to run) and react-script\'s ' +
+          'flow server.\n' +
+          'You should run: \n' +
+          'npm install -g flow-bin@' + flowVersion
+        ));
+      } else if(flowErrOutput.indexOf("still initializing") < 0) {
+        return cb(new Error(flowErrOutput));
+      }
+    }
+    cb(null, flowOutput);
+  });
 };
 
 module.exports = FlowTypecheckPlugin;
diff --git a/packages/react-dev-utils/package.json b/packages/react-dev-utils/package.json
index 0befc5d4dc4..18f5ced7c05 100644
--- a/packages/react-dev-utils/package.json
+++ b/packages/react-dev-utils/package.json
@@ -27,6 +27,7 @@
     "ansi-html": "0.0.5",
     "chalk": "1.1.3",
     "escape-string-regexp": "1.0.5",
+    "flow-bin": "^0.36.0",
     "html-entities": "1.2.0",
     "opn": "4.0.2",
     "sockjs-client": "1.0.3",
diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index 97fdb25913d..20f46521887 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -236,7 +236,8 @@ module.exports = {
         '',
         '[libs]',
         './flow-typed'
-      ]
+      ],
+      flowVersion: "0.36.0",
     })
   ],
   // Some libraries import Node modules but don't use them in the browser.

From 8ce4c6f3ece18914c96331a09baaf859c329e1f9 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 22:20:25 +0100
Subject: [PATCH 07/31] Add flow ignore comment to the start hints

---
 packages/react-scripts/scripts/start.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/react-scripts/scripts/start.js b/packages/react-scripts/scripts/start.js
index 752bd8a08a8..c640b5b6f15 100644
--- a/packages/react-scripts/scripts/start.js
+++ b/packages/react-scripts/scripts/start.js
@@ -131,6 +131,7 @@ function setupCompiler(host, port, protocol) {
       console.log('You may use special comments to disable some warnings.');
       console.log('Use ' + chalk.yellow('// eslint-disable-next-line') + ' to ignore the next line.');
       console.log('Use ' + chalk.yellow('/* eslint-disable */') + ' to ignore all warnings in a file.');
+      console.log('Use ' + chalk.yellow('// $FlowFixMe') + ' to ignore flow-related warnings on the next line.');
     }
   });
 }

From 79911f824892d75d09b00e6ae671e99d054b3f97 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 23:11:52 +0100
Subject: [PATCH 08/31] Add flow-typed resolution at start

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 47 ++++++++++++++-----
 packages/react-dev-utils/package.json         |  1 +
 .../config/webpack.config.dev.js              |  3 ++
 .../config/webpack.config.prod.js             |  7 ++-
 4 files changed, 46 insertions(+), 12 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index 6dc631aa7e9..d5042538449 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -1,7 +1,8 @@
 var fs = require('fs');
 var path = require('path');
-var flowBinPath = require('flow-bin');
 var childProcess = require('child_process');
+var flowBinPath = require('flow-bin');
+const flowTypedPath = path.join(__dirname, 'node_modules', '.bin', 'flow-typed');
 
 function FlowTypecheckPlugin(options) {
   this.options = options || {};
@@ -10,12 +11,14 @@ function FlowTypecheckPlugin(options) {
   // If flow should run in a current compilation
   this._flowShouldRun = false;
   // Stores the last flow output
-  this._flowOutput = "";
+  this._flowOutput = '';
   // Flow server process
   this._flowServer = null;
+  this._flowServerStderr = '';
 }
 
 FlowTypecheckPlugin.prototype.apply = function(compiler) {
+  var version = this.options.flowVersion || 'latest';
   compiler.plugin('compilation', function(compilation, params) {
     // Detect the presence of flow and initialize it
     compilation.plugin('normal-module-loader', function(loaderContext, module) {
@@ -26,7 +29,7 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
         loaderContext.fs.readFile(module.resource, function(err, data) {
           if (data && data.toString().indexOf('@flow') >= 0) {
             if (!this._flowInitialized) {
-              this._initializeFlow(compiler.options.context);
+              this._initializeFlow(compiler.options.context, version);
               this._flowInitialized = true;
             }
             this._flowShouldRun = true;
@@ -41,7 +44,6 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
     // Only if a file with @ flow has been changed
     if (this._flowShouldRun) {
       this._flowShouldRun = false;
-      var version = this.options.flowVersion || 'latest';
       this._flowCheck(compiler.options.context, version, function(err, flowOutput) {
         if (err) {
           compilation.errors.push(err.message);
@@ -65,19 +67,40 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
 };
 
 // This initializer will run once per webpack run (runs once across all compilations)
-FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath) {
+FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath, flowVersion) {
   const flowconfigPath = path.join(projectPath, '.flowconfig');
   fs.exists(flowconfigPath, function(exists) {
     if (!exists) {
       fs.writeFile(flowconfigPath, (this.options.flowconfig || []).join('\n'));
     }
   }.bind(this));
-  // TODO: run flow-typed
-  this._flowServer = childProcess.spawn(
-    flowBinPath,
-    ['server'],
+  childProcess.exec(
+    flowTypedPath + ' install --overwrite --flowVersion=' + flowVersion,
     { cwd: projectPath }
   );
+  var otherTypeDefs = this.options.otherFlowTypedDefs;
+  Object.keys(otherTypeDefs || {}).forEach(function(packageName) {
+    childProcess.exec(
+      flowTypedPath + ' install ' + packageName + '@' + otherTypeDefs[packageName] + ' --overwrite --flowVersion=' + flowVersion,
+      { cwd: projectPath }
+    );
+  })
+  function spawnServer() {
+    this._flowServer = childProcess.spawn(
+      flowBinPath,
+      ['server'],
+      { cwd: projectPath }
+    );
+    this._flowServer.stderr.on('data', function(chunk) {
+      this._flowServerStderr += chunk.toString();
+    }.bind(this));
+    this._flowServer.on('exit', function() {
+      if (this._flowServerStderr.indexOf('Lib files changed')) {
+        spawnServer();
+      }
+    }.bind(this));
+  };
+  spawnServer.call(this);
 };
 
 // This check will run each time a compilation sees a file with @ flow change
@@ -99,7 +122,9 @@ FlowTypecheckPlugin.prototype._flowCheck = function(projectPath, flowVersion, cb
     if (flowErrOutput.length > 0) {
       if (flowErrOutput.indexOf("There is no Flow server running") >= 0) {
         return cb(new Error(
-          'flow server: unexpectedly died.\n' +
+          'flow server: unexpectedly died.\n\n' +
+          this._flowServerStderr +
+          '\n' +
           'This is likely due to a version mismatch between a global flow ' +
           'server (that you or your IDE may try to run) and react-script\'s ' +
           'flow server.\n' +
@@ -111,7 +136,7 @@ FlowTypecheckPlugin.prototype._flowCheck = function(projectPath, flowVersion, cb
       }
     }
     cb(null, flowOutput);
-  });
+  }.bind(this));
 };
 
 module.exports = FlowTypecheckPlugin;
diff --git a/packages/react-dev-utils/package.json b/packages/react-dev-utils/package.json
index 18f5ced7c05..5036d70cd54 100644
--- a/packages/react-dev-utils/package.json
+++ b/packages/react-dev-utils/package.json
@@ -28,6 +28,7 @@
     "chalk": "1.1.3",
     "escape-string-regexp": "1.0.5",
     "flow-bin": "^0.36.0",
+    "flow-typed": "^2.0.0",
     "html-entities": "1.2.0",
     "opn": "4.0.2",
     "sockjs-client": "1.0.3",
diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index 20f46521887..d53fd975433 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -238,6 +238,9 @@ module.exports = {
         './flow-typed'
       ],
       flowVersion: "0.36.0",
+      otherFlowTypedDefs: {
+        jest: "17.0.0"
+      }
     })
   ],
   // Some libraries import Node modules but don't use them in the browser.
diff --git a/packages/react-scripts/config/webpack.config.prod.js b/packages/react-scripts/config/webpack.config.prod.js
index bf98cfac6a7..b8ea5db40b8 100644
--- a/packages/react-scripts/config/webpack.config.prod.js
+++ b/packages/react-scripts/config/webpack.config.prod.js
@@ -280,7 +280,12 @@ module.exports = {
       hashFuncNames: ['sha256', 'sha384']
     }),
     // Run Flow only if we see some @ flow annotations, will error on CI
-    new FlowTypecheckPlugin({})
+    new FlowTypecheckPlugin({
+      flowVersion: "0.36.0",
+      otherFlowTypedDefs: {
+        jest: "17.0.0"
+      }
+    })
   ],
   // Some libraries import Node modules but don't use them in the browser.
   // Tell Webpack to provide empty mocks for them so importing them works.

From e4b915cd6c12167a010e833f2351b7400f7efbcc Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 23:12:36 +0100
Subject: [PATCH 09/31] Reset server stderr on restart

---
 packages/react-dev-utils/FlowTypecheckPlugin.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index d5042538449..5435607bd3e 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -96,6 +96,7 @@ FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath, flowVersio
     }.bind(this));
     this._flowServer.on('exit', function() {
       if (this._flowServerStderr.indexOf('Lib files changed')) {
+        this._flowServerStderr = "";
         spawnServer();
       }
     }.bind(this));

From d724efef22ceb97df1dce0140a4b925632606bab Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 23:35:05 +0100
Subject: [PATCH 10/31] Move options as explicit props of the plugin

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 22 ++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index 5435607bd3e..fe5fe3db985 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -5,7 +5,15 @@ var flowBinPath = require('flow-bin');
 const flowTypedPath = path.join(__dirname, 'node_modules', '.bin', 'flow-typed');
 
 function FlowTypecheckPlugin(options) {
-  this.options = options || {};
+  options = options || {};
+  // The flow-bin version
+  this.flowVersion = options.flowVersion || 'latest';
+  // Contents of the generated .flowconfig if it doesn't exist
+  this.flowconfig = options.flowconfig || [];
+  // Load up other flow-typed defs outside of the package.json (implicit packages behind react-scripts)
+  // Key is the package name, value is the version number
+  this.otherFlowTypedDefs = options.otherFlowTypedDefs || {};
+  
   // If flow is globally present in the project, this will stay across compilations
   this._flowInitialized = false;
   // If flow should run in a current compilation
@@ -18,7 +26,6 @@ function FlowTypecheckPlugin(options) {
 }
 
 FlowTypecheckPlugin.prototype.apply = function(compiler) {
-  var version = this.options.flowVersion || 'latest';
   compiler.plugin('compilation', function(compilation, params) {
     // Detect the presence of flow and initialize it
     compilation.plugin('normal-module-loader', function(loaderContext, module) {
@@ -29,7 +36,7 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
         loaderContext.fs.readFile(module.resource, function(err, data) {
           if (data && data.toString().indexOf('@flow') >= 0) {
             if (!this._flowInitialized) {
-              this._initializeFlow(compiler.options.context, version);
+              this._initializeFlow(compiler.options.context, this.flowVersion);
               this._flowInitialized = true;
             }
             this._flowShouldRun = true;
@@ -44,7 +51,7 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
     // Only if a file with @ flow has been changed
     if (this._flowShouldRun) {
       this._flowShouldRun = false;
-      this._flowCheck(compiler.options.context, version, function(err, flowOutput) {
+      this._flowCheck(compiler.options.context, this.flowVersion, function(err, flowOutput) {
         if (err) {
           compilation.errors.push(err.message);
           return callback();
@@ -71,17 +78,16 @@ FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath, flowVersio
   const flowconfigPath = path.join(projectPath, '.flowconfig');
   fs.exists(flowconfigPath, function(exists) {
     if (!exists) {
-      fs.writeFile(flowconfigPath, (this.options.flowconfig || []).join('\n'));
+      fs.writeFile(flowconfigPath, this.flowconfig.join('\n'));
     }
   }.bind(this));
   childProcess.exec(
     flowTypedPath + ' install --overwrite --flowVersion=' + flowVersion,
     { cwd: projectPath }
   );
-  var otherTypeDefs = this.options.otherFlowTypedDefs;
-  Object.keys(otherTypeDefs || {}).forEach(function(packageName) {
+  Object.keys(this.otherFlowTypedDefs).forEach(function(packageName) {
     childProcess.exec(
-      flowTypedPath + ' install ' + packageName + '@' + otherTypeDefs[packageName] + ' --overwrite --flowVersion=' + flowVersion,
+      flowTypedPath + ' install ' + packageName + '@' + this.otherFlowTypedDefs[packageName] + ' --overwrite --flowVersion=' + flowVersion,
       { cwd: projectPath }
     );
   })

From a4e56321c8f70e4e0a2f001b394b16f29b3000a1 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Sun, 4 Dec 2016 23:40:34 +0100
Subject: [PATCH 11/31] Use arrow functions

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 42 +++++++++----------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index fe5fe3db985..62f9110492c 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -26,14 +26,14 @@ function FlowTypecheckPlugin(options) {
 }
 
 FlowTypecheckPlugin.prototype.apply = function(compiler) {
-  compiler.plugin('compilation', function(compilation, params) {
+  compiler.plugin('compilation', (compilation, params) => {
     // Detect the presence of flow and initialize it
-    compilation.plugin('normal-module-loader', function(loaderContext, module) {
+    compilation.plugin('normal-module-loader', (loaderContext, module) => {
       // We're only checking the presence of flow in non-node_modules
       // (some dependencies may keep their flow comments, we don't want to match them)
       if (module.resource.indexOf("node_modules") < 0) {
         // We use webpack's cached FileSystem to avoid slowing down compilation
-        loaderContext.fs.readFile(module.resource, function(err, data) {
+        loaderContext.fs.readFile(module.resource, (err, data) => {
           if (data && data.toString().indexOf('@flow') >= 0) {
             if (!this._flowInitialized) {
               this._initializeFlow(compiler.options.context, this.flowVersion);
@@ -41,17 +41,17 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
             }
             this._flowShouldRun = true;
           }
-        }.bind(this));
+        });
       }
-    }.bind(this))
-  }.bind(this));
+    })
+  });
 
   // While emitting run a flow check if flow has been detected
-  compiler.plugin('emit', function(compilation, callback) {
+  compiler.plugin('emit', (compilation, callback) => {
     // Only if a file with @ flow has been changed
     if (this._flowShouldRun) {
       this._flowShouldRun = false;
-      this._flowCheck(compiler.options.context, this.flowVersion, function(err, flowOutput) {
+      this._flowCheck(compiler.options.context, this.flowVersion, (err, flowOutput) => {
         if (err) {
           compilation.errors.push(err.message);
           return callback();
@@ -62,7 +62,7 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
           compilation.warnings.push(this._flowOutput);
         }
         callback();
-      }.bind(this));
+      });
     } else {
       // Output a warning if flow failed in a previous run
       if (this._flowOutput.length > 0 && this._flowOutput.indexOf('No errors!') < 0) {
@@ -70,22 +70,22 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
       }
       callback();
     }
-  }.bind(this));
+  });
 };
 
 // This initializer will run once per webpack run (runs once across all compilations)
 FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath, flowVersion) {
   const flowconfigPath = path.join(projectPath, '.flowconfig');
-  fs.exists(flowconfigPath, function(exists) {
+  fs.exists(flowconfigPath, (exists) => {
     if (!exists) {
       fs.writeFile(flowconfigPath, this.flowconfig.join('\n'));
     }
-  }.bind(this));
+  });
   childProcess.exec(
     flowTypedPath + ' install --overwrite --flowVersion=' + flowVersion,
     { cwd: projectPath }
   );
-  Object.keys(this.otherFlowTypedDefs).forEach(function(packageName) {
+  Object.keys(this.otherFlowTypedDefs).forEach((packageName) => {
     childProcess.exec(
       flowTypedPath + ' install ' + packageName + '@' + this.otherFlowTypedDefs[packageName] + ' --overwrite --flowVersion=' + flowVersion,
       { cwd: projectPath }
@@ -97,15 +97,15 @@ FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath, flowVersio
       ['server'],
       { cwd: projectPath }
     );
-    this._flowServer.stderr.on('data', function(chunk) {
+    this._flowServer.stderr.on('data', (chunk) => {
       this._flowServerStderr += chunk.toString();
-    }.bind(this));
-    this._flowServer.on('exit', function() {
+    });
+    this._flowServer.on('exit', () => {
       if (this._flowServerStderr.indexOf('Lib files changed')) {
         this._flowServerStderr = "";
         spawnServer();
       }
-    }.bind(this));
+    });
   };
   spawnServer.call(this);
 };
@@ -119,13 +119,13 @@ FlowTypecheckPlugin.prototype._flowCheck = function(projectPath, flowVersion, cb
     ['status', '--no-auto-start', '--color=always'],
     { cwd: projectPath }
   );
-  statusCheck.stdout.on('data', function(chunk) {
+  statusCheck.stdout.on('data', (chunk) => {
     flowOutput += chunk.toString();
   });
-  statusCheck.stderr.on('data', function(chunk) {
+  statusCheck.stderr.on('data', (chunk) => {
     flowErrOutput += chunk.toString();
   });
-  statusCheck.on('close', function() {
+  statusCheck.on('close', () => {
     if (flowErrOutput.length > 0) {
       if (flowErrOutput.indexOf("There is no Flow server running") >= 0) {
         return cb(new Error(
@@ -143,7 +143,7 @@ FlowTypecheckPlugin.prototype._flowCheck = function(projectPath, flowVersion, cb
       }
     }
     cb(null, flowOutput);
-  }.bind(this));
+  });
 };
 
 module.exports = FlowTypecheckPlugin;

From 64f36ec78dd679e393514e1f896a438bcacaa35b Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 00:42:11 +0100
Subject: [PATCH 12/31] Refactor using promises and no class attrs

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 196 +++++++++---------
 1 file changed, 97 insertions(+), 99 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index 62f9110492c..fa6ee8ec06f 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -4,6 +4,81 @@ var childProcess = require('child_process');
 var flowBinPath = require('flow-bin');
 const flowTypedPath = path.join(__dirname, 'node_modules', '.bin', 'flow-typed');
 
+function execOneTime(command, args, options) {
+  return new Promise((resolve) => {
+    childProcess.exec(
+      command + ' ' + (args || []).join(' '),
+      (options || {}),
+      (error, stdout, stderr) => {
+        resolve({
+          error: error,
+          stdout: stdout,
+          stderr: stderr
+        });
+      }
+    )
+  });
+}
+
+function writeFileIfDoesNotExist(path, data) {
+  return new Promise((resolve, reject) => {
+    fs.exists(path, exists => {
+      if (!exists) {
+        fs.writeFile(path, data, err => {
+          if (err) {
+            reject(err);
+          }
+          resolve(data);
+        });
+      }
+    });
+  });
+}
+
+function initializeFlow(projectPath, flowVersion, flowconfig, otherFlowTypedDefs) {
+  const flowconfigPath = path.join(projectPath, '.flowconfig');
+  Promise.all(
+    [
+      writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n')),
+      execOneTime(
+        flowTypedPath,
+        ['install', '--overwrite', '--flowVersion=' + flowVersion],
+        { cwd: projectPath }
+      )
+    ].concat(
+      Object.keys(otherFlowTypedDefs).map((packageName) => execOneTime(
+        flowTypedPath,
+        [
+          'install',
+          packageName + '@' + otherFlowTypedDefs[packageName],
+          '--overwrite',
+          '--flowVersion=' + flowVersion
+        ],
+        { cwd: projectPath }
+      ))
+    )
+  );
+}
+
+function flowCheck(projectPath, flowVersion) {
+  return execOneTime(
+    flowBinPath,
+    ['status', '--color=always'],
+    { cwd: projectPath }
+  )
+  .then(res => {
+    var flowOutput = res.stdout;
+    var flowErrOutput = res.stderr;
+    if (flowErrOutput.length > 0) {
+      if(flowErrOutput.indexOf("still initializing") < 0) {
+        return Promise.reject(new Error('flow server:\n' + flowErrOutput));
+      }
+    }
+    return flowOutput;
+  });
+}
+
+
 function FlowTypecheckPlugin(options) {
   options = options || {};
   // The flow-bin version
@@ -13,19 +88,12 @@ function FlowTypecheckPlugin(options) {
   // Load up other flow-typed defs outside of the package.json (implicit packages behind react-scripts)
   // Key is the package name, value is the version number
   this.otherFlowTypedDefs = options.otherFlowTypedDefs || {};
-  
-  // If flow is globally present in the project, this will stay across compilations
-  this._flowInitialized = false;
-  // If flow should run in a current compilation
-  this._flowShouldRun = false;
-  // Stores the last flow output
-  this._flowOutput = '';
-  // Flow server process
-  this._flowServer = null;
-  this._flowServerStderr = '';
 }
 
 FlowTypecheckPlugin.prototype.apply = function(compiler) {
+  var flowInitialized = false;
+  var flowShouldRun = false;
+  var flowOutput = '';
   compiler.plugin('compilation', (compilation, params) => {
     // Detect the presence of flow and initialize it
     compilation.plugin('normal-module-loader', (loaderContext, module) => {
@@ -35,11 +103,14 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
         // We use webpack's cached FileSystem to avoid slowing down compilation
         loaderContext.fs.readFile(module.resource, (err, data) => {
           if (data && data.toString().indexOf('@flow') >= 0) {
-            if (!this._flowInitialized) {
-              this._initializeFlow(compiler.options.context, this.flowVersion);
-              this._flowInitialized = true;
+            if (!flowInitialized) {
+              initializeFlow(
+                compiler.options.context, this.flowVersion,
+                this.flowconfig, this.otherFlowTypedDefs
+              );
+              flowInitialized = true;
             }
-            this._flowShouldRun = true;
+            flowShouldRun = true;
           }
         });
       }
@@ -49,101 +120,28 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
   // While emitting run a flow check if flow has been detected
   compiler.plugin('emit', (compilation, callback) => {
     // Only if a file with @ flow has been changed
-    if (this._flowShouldRun) {
-      this._flowShouldRun = false;
-      this._flowCheck(compiler.options.context, this.flowVersion, (err, flowOutput) => {
-        if (err) {
-          compilation.errors.push(err.message);
-          return callback();
-        }
-        this._flowOutput = flowOutput;
+    if (flowShouldRun) {
+      flowShouldRun = false;
+      flowCheck(compiler.options.context, this.flowVersion)
+      .then(newOutput => {
+        flowOutput = newOutput;
         // Output a warning if flow failed
-        if (this._flowOutput.indexOf('No errors!') < 0) {
-          compilation.warnings.push(this._flowOutput);
+        if (flowOutput.indexOf('No errors!') < 0) {
+          compilation.warnings.push(flowOutput);
         }
         callback();
+      }, (err) => {
+        compilation.errors.push(err.message);
+        callback();
       });
     } else {
       // Output a warning if flow failed in a previous run
-      if (this._flowOutput.length > 0 && this._flowOutput.indexOf('No errors!') < 0) {
-        compilation.warnings.push(this._flowOutput);
+      if (flowOutput.length > 0 && flowOutput.indexOf('No errors!') < 0) {
+        compilation.warnings.push(flowOutput);
       }
       callback();
     }
   });
 };
 
-// This initializer will run once per webpack run (runs once across all compilations)
-FlowTypecheckPlugin.prototype._initializeFlow = function(projectPath, flowVersion) {
-  const flowconfigPath = path.join(projectPath, '.flowconfig');
-  fs.exists(flowconfigPath, (exists) => {
-    if (!exists) {
-      fs.writeFile(flowconfigPath, this.flowconfig.join('\n'));
-    }
-  });
-  childProcess.exec(
-    flowTypedPath + ' install --overwrite --flowVersion=' + flowVersion,
-    { cwd: projectPath }
-  );
-  Object.keys(this.otherFlowTypedDefs).forEach((packageName) => {
-    childProcess.exec(
-      flowTypedPath + ' install ' + packageName + '@' + this.otherFlowTypedDefs[packageName] + ' --overwrite --flowVersion=' + flowVersion,
-      { cwd: projectPath }
-    );
-  })
-  function spawnServer() {
-    this._flowServer = childProcess.spawn(
-      flowBinPath,
-      ['server'],
-      { cwd: projectPath }
-    );
-    this._flowServer.stderr.on('data', (chunk) => {
-      this._flowServerStderr += chunk.toString();
-    });
-    this._flowServer.on('exit', () => {
-      if (this._flowServerStderr.indexOf('Lib files changed')) {
-        this._flowServerStderr = "";
-        spawnServer();
-      }
-    });
-  };
-  spawnServer.call(this);
-};
-
-// This check will run each time a compilation sees a file with @ flow change
-FlowTypecheckPlugin.prototype._flowCheck = function(projectPath, flowVersion, cb) {
-  var flowOutput = "";
-  var flowErrOutput = "";
-  var statusCheck = childProcess.spawn(
-    flowBinPath,
-    ['status', '--no-auto-start', '--color=always'],
-    { cwd: projectPath }
-  );
-  statusCheck.stdout.on('data', (chunk) => {
-    flowOutput += chunk.toString();
-  });
-  statusCheck.stderr.on('data', (chunk) => {
-    flowErrOutput += chunk.toString();
-  });
-  statusCheck.on('close', () => {
-    if (flowErrOutput.length > 0) {
-      if (flowErrOutput.indexOf("There is no Flow server running") >= 0) {
-        return cb(new Error(
-          'flow server: unexpectedly died.\n\n' +
-          this._flowServerStderr +
-          '\n' +
-          'This is likely due to a version mismatch between a global flow ' +
-          'server (that you or your IDE may try to run) and react-script\'s ' +
-          'flow server.\n' +
-          'You should run: \n' +
-          'npm install -g flow-bin@' + flowVersion
-        ));
-      } else if(flowErrOutput.indexOf("still initializing") < 0) {
-        return cb(new Error(flowErrOutput));
-      }
-    }
-    cb(null, flowOutput);
-  });
-};
-
 module.exports = FlowTypecheckPlugin;

From bf66320e50dbac099d8f7ff1f8607a5df3f07730 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 01:47:54 +0100
Subject: [PATCH 13/31] Add documentation for out-of-the-box flow

---
 packages/react-scripts/template/README.md | 25 +++++++++--------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/packages/react-scripts/template/README.md b/packages/react-scripts/template/README.md
index bdb88df6023..e3ef399bfc5 100644
--- a/packages/react-scripts/template/README.md
+++ b/packages/react-scripts/template/README.md
@@ -444,28 +444,23 @@ Now you are ready to use the imported React Bootstrap components within your com
 
 ## Adding Flow
 
-Flow typing is currently [not supported out of the box](https://github.com/facebookincubator/create-react-app/issues/72) with the default `.flowconfig` generated by Flow. If you run it, you might get errors like this:
+Flow typing is now supported out of the box. All you have to do is add the `/* @flow */` comment on top of files you
+want to typecheck. If no `.flowconfig` is present, one will be generated for you. The script will also download type
+definitions from [flow-typed](https://github.com/flowtype/flow-typed) automatically.
 
-```js
-node_modules/fbjs/lib/Deferred.js.flow:60
- 60:     Promise.prototype.done.apply(this._promise, arguments);
-                           ^^^^ property `done`. Property not found in
-495: declare class Promise<+R> {
-     ^ Promise. See lib: /private/tmp/flow/flowlib_34952d31/core.js:495
-
-node_modules/fbjs/lib/shallowEqual.js.flow:29
- 29:     return x !== 0 || 1 / (x: $FlowIssue) === 1 / (y: $FlowIssue);
-                                   ^^^^^^^^^^ identifier `$FlowIssue`. Could not resolve name
-```
-
-To fix this, change your `.flowconfig` to look like this:
+If you don't have the auto-generated `.flowconfig` because you had flow setup before, you can copy it from here:
 
 ```ini
 [ignore]
 <PROJECT_ROOT>/node_modules/fbjs/.*
+
+[libs]
+./flow-typed
 ```
 
-Re-run flow, and you shouldn’t get any extra issues.
+Flow errors will show up alongside eslint errors as you work on your application.
+
+>Note: If your global flow installation version differs from react-scripts's flow version, you may experience slower compilation times while going back and forth between your app and your IDE (that may use your global flow). Ensure you have the same `flow-bin` version [here](https://github.com/facebookincubator/create-react-app/blob/master/packages/react-dev-utils/package.json).
 
 ## Adding Custom Environment Variables
 

From 7e65c5d3e8abec1cdfd5768275c8d8f770b24ea2 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 16:26:12 +0100
Subject: [PATCH 14/31] Schedule project init to complete before 1st check

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 27 ++++++++++++++-----
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index fa6ee8ec06f..c246d782919 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -30,6 +30,8 @@ function writeFileIfDoesNotExist(path, data) {
           }
           resolve(data);
         });
+      } else {
+        resolve(data);
       }
     });
   });
@@ -37,7 +39,7 @@ function writeFileIfDoesNotExist(path, data) {
 
 function initializeFlow(projectPath, flowVersion, flowconfig, otherFlowTypedDefs) {
   const flowconfigPath = path.join(projectPath, '.flowconfig');
-  Promise.all(
+  return Promise.all(
     [
       writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n')),
       execOneTime(
@@ -91,7 +93,9 @@ function FlowTypecheckPlugin(options) {
 }
 
 FlowTypecheckPlugin.prototype.apply = function(compiler) {
+  var flowActiveOnProject = false;
   var flowInitialized = false;
+  var flowInitializationPromise;
   var flowShouldRun = false;
   var flowOutput = '';
   compiler.plugin('compilation', (compilation, params) => {
@@ -103,12 +107,20 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
         // We use webpack's cached FileSystem to avoid slowing down compilation
         loaderContext.fs.readFile(module.resource, (err, data) => {
           if (data && data.toString().indexOf('@flow') >= 0) {
-            if (!flowInitialized) {
-              initializeFlow(
+            if (!flowActiveOnProject) {
+              flowInitializationPromise = initializeFlow(
                 compiler.options.context, this.flowVersion,
                 this.flowconfig, this.otherFlowTypedDefs
-              );
-              flowInitialized = true;
+              )
+              .then(() => {
+                flowInitialized = true;
+              }, (e) => {
+                loaderContext.emitWarning(new Error(
+                  'Flow project initialization warning:\n' +
+                  e.message
+                ));
+              });
+              flowActiveOnProject = true;
             }
             flowShouldRun = true;
           }
@@ -122,7 +134,10 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
     // Only if a file with @ flow has been changed
     if (flowShouldRun) {
       flowShouldRun = false;
-      flowCheck(compiler.options.context, this.flowVersion)
+      (flowInitialized ?
+        Promise.resolve() :
+        flowInitializationPromise)
+      .then(() => flowCheck(compiler.options.context, this.flowVersion))
       .then(newOutput => {
         flowOutput = newOutput;
         // Output a warning if flow failed

From c001833c4ab8a16d8b7f54fda95e85d379700ace Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 16:59:17 +0100
Subject: [PATCH 15/31] Process code-based flow checks

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 88 +++++++++++--------
 1 file changed, 50 insertions(+), 38 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index c246d782919..23211f19e11 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -4,19 +4,44 @@ var childProcess = require('child_process');
 var flowBinPath = require('flow-bin');
 const flowTypedPath = path.join(__dirname, 'node_modules', '.bin', 'flow-typed');
 
+function stripFlowLoadingIndicators(message) {
+  var newMessage = message;
+  var launchingIndex = newMessage.indexOf("Launching Flow server for");
+  if (launchingIndex >= 0) {
+    newMessage = newMessage.slice(0, launchingIndex);
+  }
+  var stillIndex = newMessage.indexOf("flow is still initializing");
+  if (stillIndex >= 0) {
+    newMessage = newMessage.slice(0, stillIndex);
+  }
+  return newMessage;
+}
+
 function execOneTime(command, args, options) {
-  return new Promise((resolve) => {
-    childProcess.exec(
-      command + ' ' + (args || []).join(' '),
-      (options || {}),
-      (error, stdout, stderr) => {
-        resolve({
-          error: error,
-          stdout: stdout,
-          stderr: stderr
-        });
+  return new Promise((resolve, reject) => {
+    var stdout = new Buffer("");
+    var stderr = new Buffer("");
+    var oneTimeProcess = childProcess.spawn(
+      command,
+      args,
+      options
+    );
+    oneTimeProcess.stdout.on('data', chunk => {
+      stdout = Buffer.concat([stdout, chunk]);
+    });
+    oneTimeProcess.stderr.on('data', chunk => {
+      stderr = Buffer.concat([stderr, chunk]);
+    });
+    oneTimeProcess.on('exit', code => {
+      switch (code) {
+        case 0:
+          return resolve(stdout);
+        default:
+          return reject(new Error(
+            Buffer.concat([stdout, stderr]).toString()
+          ));
       }
-    )
+    });
   });
 }
 
@@ -67,17 +92,7 @@ function flowCheck(projectPath, flowVersion) {
     flowBinPath,
     ['status', '--color=always'],
     { cwd: projectPath }
-  )
-  .then(res => {
-    var flowOutput = res.stdout;
-    var flowErrOutput = res.stderr;
-    if (flowErrOutput.length > 0) {
-      if(flowErrOutput.indexOf("still initializing") < 0) {
-        return Promise.reject(new Error('flow server:\n' + flowErrOutput));
-      }
-    }
-    return flowOutput;
-  });
+  );
 }
 
 
@@ -97,9 +112,10 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
   var flowInitialized = false;
   var flowInitializationPromise;
   var flowShouldRun = false;
-  var flowOutput = '';
+  var flowErrorOutput = null;
+
+  // During module traversal, assert the presence of an @ flow in a module
   compiler.plugin('compilation', (compilation, params) => {
-    // Detect the presence of flow and initialize it
     compilation.plugin('normal-module-loader', (loaderContext, module) => {
       // We're only checking the presence of flow in non-node_modules
       // (some dependencies may keep their flow comments, we don't want to match them)
@@ -129,7 +145,7 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
     })
   });
 
-  // While emitting run a flow check if flow has been detected
+  // While emitting, run a flow check if flow has been detected
   compiler.plugin('emit', (compilation, callback) => {
     // Only if a file with @ flow has been changed
     if (flowShouldRun) {
@@ -138,21 +154,17 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
         Promise.resolve() :
         flowInitializationPromise)
       .then(() => flowCheck(compiler.options.context, this.flowVersion))
-      .then(newOutput => {
-        flowOutput = newOutput;
-        // Output a warning if flow failed
-        if (flowOutput.indexOf('No errors!') < 0) {
-          compilation.warnings.push(flowOutput);
-        }
-        callback();
-      }, (err) => {
-        compilation.errors.push(err.message);
-        callback();
-      });
+      .then(() => {
+        flowErrorOutput = null;
+      }, error => {
+        flowErrorOutput = stripFlowLoadingIndicators(error.message);
+        compilation.warnings.push(flowErrorOutput);
+      })
+      .then(callback);
     } else {
       // Output a warning if flow failed in a previous run
-      if (flowOutput.length > 0 && flowOutput.indexOf('No errors!') < 0) {
-        compilation.warnings.push(flowOutput);
+      if (flowErrorOutput) {
+        compilation.warnings.push(flowErrorOutput);
       }
       callback();
     }

From aa76ae5a86dd3fbe44533552c0a0c5e8fb4e004c Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 17:21:39 +0100
Subject: [PATCH 16/31] Get flow version internally without config

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 75 ++++++++++++-------
 .../config/webpack.config.dev.js              |  1 -
 .../config/webpack.config.prod.js             |  1 -
 3 files changed, 48 insertions(+), 29 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index 23211f19e11..d28fe5d6dcc 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -62,32 +62,57 @@ function writeFileIfDoesNotExist(path, data) {
   });
 }
 
-function initializeFlow(projectPath, flowVersion, flowconfig, otherFlowTypedDefs) {
-  const flowconfigPath = path.join(projectPath, '.flowconfig');
-  return Promise.all(
-    [
-      writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n')),
+function getFlowPath(globalInstall) {
+  return (
+    globalInstall ?
       execOneTime(
-        flowTypedPath,
-        ['install', '--overwrite', '--flowVersion=' + flowVersion],
-        { cwd: projectPath }
+        '/bin/sh',
+        ['-c', 'which flow']
       )
-    ].concat(
-      Object.keys(otherFlowTypedDefs).map((packageName) => execOneTime(
-        flowTypedPath,
-        [
-          'install',
-          packageName + '@' + otherFlowTypedDefs[packageName],
-          '--overwrite',
-          '--flowVersion=' + flowVersion
-        ],
-        { cwd: projectPath }
-      ))
+      .then(rawPath => {
+        var path = rawPath.toString().replace('\n', '');
+        return path.indexOf("not found") >= 0 ?
+          flowBinPath :
+          path
+      }) :
+      Promise.resolve(flowBinPath)
+  )
+}
+
+function getFlowVersion(options) {
+  return getFlowPath((options || {}).globalInstall)
+  .then(flowPath => execOneTime(
+    flowPath,
+    ['version', '--json']
+  ))
+  .then(rawData => JSON.parse(rawData))
+  .then(versionData => versionData.semver);
+}
+
+function initializeFlow(projectPath, flowconfig, otherFlowTypedDefs) {
+  const flowconfigPath = path.join(projectPath, '.flowconfig');
+  return getFlowVersion().then(localVersion => Promise.all([
+    writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n')),
+    execOneTime(
+      flowTypedPath,
+      ['install', '--overwrite', '--flowVersion=' + localVersion],
+      { cwd: projectPath }
     )
-  );
+  ].concat(
+    Object.keys(otherFlowTypedDefs).map((packageName) => execOneTime(
+      flowTypedPath,
+      [
+        'install',
+        packageName + '@' + otherFlowTypedDefs[packageName],
+        '--overwrite',
+        '--flowVersion=' + localVersion
+      ],
+      { cwd: projectPath }
+    ))
+  )));
 }
 
-function flowCheck(projectPath, flowVersion) {
+function flowCheck(projectPath) {
   return execOneTime(
     flowBinPath,
     ['status', '--color=always'],
@@ -95,11 +120,8 @@ function flowCheck(projectPath, flowVersion) {
   );
 }
 
-
 function FlowTypecheckPlugin(options) {
   options = options || {};
-  // The flow-bin version
-  this.flowVersion = options.flowVersion || 'latest';
   // Contents of the generated .flowconfig if it doesn't exist
   this.flowconfig = options.flowconfig || [];
   // Load up other flow-typed defs outside of the package.json (implicit packages behind react-scripts)
@@ -125,8 +147,7 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
           if (data && data.toString().indexOf('@flow') >= 0) {
             if (!flowActiveOnProject) {
               flowInitializationPromise = initializeFlow(
-                compiler.options.context, this.flowVersion,
-                this.flowconfig, this.otherFlowTypedDefs
+                compiler.options.context, this.flowconfig, this.otherFlowTypedDefs
               )
               .then(() => {
                 flowInitialized = true;
@@ -153,7 +174,7 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
       (flowInitialized ?
         Promise.resolve() :
         flowInitializationPromise)
-      .then(() => flowCheck(compiler.options.context, this.flowVersion))
+      .then(() => flowCheck(compiler.options.context))
       .then(() => {
         flowErrorOutput = null;
       }, error => {
diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index d53fd975433..db8e51f1027 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -237,7 +237,6 @@ module.exports = {
         '[libs]',
         './flow-typed'
       ],
-      flowVersion: "0.36.0",
       otherFlowTypedDefs: {
         jest: "17.0.0"
       }
diff --git a/packages/react-scripts/config/webpack.config.prod.js b/packages/react-scripts/config/webpack.config.prod.js
index b8ea5db40b8..3f3a2d5aaa2 100644
--- a/packages/react-scripts/config/webpack.config.prod.js
+++ b/packages/react-scripts/config/webpack.config.prod.js
@@ -281,7 +281,6 @@ module.exports = {
     }),
     // Run Flow only if we see some @ flow annotations, will error on CI
     new FlowTypecheckPlugin({
-      flowVersion: "0.36.0",
       otherFlowTypedDefs: {
         jest: "17.0.0"
       }

From 3fc87cabfe3b374803985c196e8ff90f385eafc1 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 17:52:53 +0100
Subject: [PATCH 17/31] Check global flow version

If a mismatch occurs, the DX will be bad, we should tell it to the user
---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 44 ++++++++++---------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index d28fe5d6dcc..449ba717eab 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -14,6 +14,10 @@ function stripFlowLoadingIndicators(message) {
   if (stillIndex >= 0) {
     newMessage = newMessage.slice(0, stillIndex);
   }
+  var notRespIndex = newMessage.indexOf("The flow server is not responding");
+  if (notRespIndex >= 0) {
+    newMessage = newMessage.slice(0, notRespIndex);
+  }
   return newMessage;
 }
 
@@ -32,6 +36,7 @@ function execOneTime(command, args, options) {
     oneTimeProcess.stderr.on('data', chunk => {
       stderr = Buffer.concat([stderr, chunk]);
     });
+    oneTimeProcess.on('error', error => reject(error));
     oneTimeProcess.on('exit', code => {
       switch (code) {
         case 0:
@@ -62,29 +67,11 @@ function writeFileIfDoesNotExist(path, data) {
   });
 }
 
-function getFlowPath(globalInstall) {
-  return (
-    globalInstall ?
-      execOneTime(
-        '/bin/sh',
-        ['-c', 'which flow']
-      )
-      .then(rawPath => {
-        var path = rawPath.toString().replace('\n', '');
-        return path.indexOf("not found") >= 0 ?
-          flowBinPath :
-          path
-      }) :
-      Promise.resolve(flowBinPath)
-  )
-}
-
 function getFlowVersion(options) {
-  return getFlowPath((options || {}).globalInstall)
-  .then(flowPath => execOneTime(
-    flowPath,
+  return execOneTime(
+    (options || {}).global ? "flow" : flowBinPath,
     ['version', '--json']
-  ))
+  )
   .then(rawData => JSON.parse(rawData))
   .then(versionData => versionData.semver);
 }
@@ -92,6 +79,21 @@ function getFlowVersion(options) {
 function initializeFlow(projectPath, flowconfig, otherFlowTypedDefs) {
   const flowconfigPath = path.join(projectPath, '.flowconfig');
   return getFlowVersion().then(localVersion => Promise.all([
+    getFlowVersion({global: true}).catch(() => localVersion)
+    .then(globalVersion =>
+      globalVersion !== localVersion ?
+        Promise.reject(new Error(
+          'Your global flow version does not match react-script\'s flow version.\n\n' +
+          'Having two different versions is likely to restart your flow server ' +
+          'regularly while you go back and forth between your App and your IDE ' +
+          '(that is likely to rely on your global flow installation). ' +
+          'This will slow down significantly your development experience. ' +
+          'In order to avoid this, ensure you have flow ' + localVersion + ' globally ' +
+          '(your current global version is ' + globalVersion + ').\n\n' +
+          'Run `npm install -g flow-bin@' + localVersion + '` to fix this.'
+        )) :
+        true
+    ),
     writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n')),
     execOneTime(
       flowTypedPath,

From 251bd9bcdd1219cc14423d836b8e693ef468f2b9 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 18:05:44 +0100
Subject: [PATCH 18/31] Add flow-typed to gitignore automatically

---
 .../react-dev-utils/FlowTypecheckPlugin.js    | 35 ++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index 449ba717eab..8bbd67b34b2 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -56,7 +56,7 @@ function writeFileIfDoesNotExist(path, data) {
       if (!exists) {
         fs.writeFile(path, data, err => {
           if (err) {
-            reject(err);
+            return reject(err);
           }
           resolve(data);
         });
@@ -67,6 +67,37 @@ function writeFileIfDoesNotExist(path, data) {
   });
 }
 
+function writeInFileIfNotPresent(path, contentToAssert, contentToAppend) {
+  return new Promise((resolve, reject) => {
+    fs.exists(path, exists => {
+      if (!exists) {
+        fs.writeFile(path, contentToAppend, err => {
+          if (err) {
+            return reject(err);
+          }
+          resolve(contentToAppend);
+        });
+      } else {
+        fs.readFile(path, (err, existingContent) => {
+          if (err) {
+            return reject(err);
+          }
+          if (existingContent.indexOf(contentToAssert) < 0) {
+            fs.appendFile(path, contentToAppend, err => {
+              if (err) {
+                return reject(err);
+              }
+              resolve(contentToAppend);
+            });
+          } else {
+            resolve(contentToAppend);
+          }
+        });
+      }
+    });
+  });
+}
+
 function getFlowVersion(options) {
   return execOneTime(
     (options || {}).global ? "flow" : flowBinPath,
@@ -78,6 +109,7 @@ function getFlowVersion(options) {
 
 function initializeFlow(projectPath, flowconfig, otherFlowTypedDefs) {
   const flowconfigPath = path.join(projectPath, '.flowconfig');
+  const gitignorePath = path.join(projectPath, '.gitignore');
   return getFlowVersion().then(localVersion => Promise.all([
     getFlowVersion({global: true}).catch(() => localVersion)
     .then(globalVersion =>
@@ -95,6 +127,7 @@ function initializeFlow(projectPath, flowconfig, otherFlowTypedDefs) {
         true
     ),
     writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n')),
+    writeInFileIfNotPresent(gitignorePath, 'flow-typed', 'flow-typed'),
     execOneTime(
       flowTypedPath,
       ['install', '--overwrite', '--flowVersion=' + localVersion],

From 4ed28fd74c07baec8338e4ffd29126bb6ce3285b Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 18:56:27 +0100
Subject: [PATCH 19/31] Add optional flow to end to end testing

---
 tasks/e2e.sh | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/tasks/e2e.sh b/tasks/e2e.sh
index ce7b50f35b5..7a47d99fef8 100755
--- a/tasks/e2e.sh
+++ b/tasks/e2e.sh
@@ -143,6 +143,7 @@ test -e build/static/js/*.js
 test -e build/static/css/*.css
 test -e build/static/media/*.svg
 test -e build/favicon.ico
+test ! -e .flowconfig
 
 # Run tests with CI flag
 CI=true npm test
@@ -152,6 +153,23 @@ CI=true npm test
 # Test the server
 npm start -- --smoke-test
 
+# Test optional flow enabling
+cp src/App.js src/App.backup.js
+cp .gitignore .gitignore.backup
+echo "
+/* @flow */
+var wrong: string = 0;
+" >> src/App.js
+npm start -- --smoke-test || true
+test -e .flowconfig
+test -d flow-typed
+cat .gitignore | grep flow-typed
+rm src/App.js .gitignore
+cp src/App.backup.js src/App.js
+cp .gitignore.backup .gitignore
+rm src/App.backup.js .gitignore.backup .flowconfig
+rm -rf flow-typed
+
 # ******************************************************************************
 # Finally, let's check that everything still works after ejecting.
 # ******************************************************************************
@@ -173,6 +191,7 @@ test -e build/static/js/*.js
 test -e build/static/css/*.css
 test -e build/static/media/*.svg
 test -e build/favicon.ico
+test ! -e .flowconfig
 
 # Run tests, overring the watch option to disable it.
 # `CI=true npm test` won't work here because `npm test` becomes just `jest`.
@@ -185,6 +204,22 @@ npm test -- --watch=no
 # Test the server
 npm start -- --smoke-test
 
+# Test optional flow enabling
+cp src/App.js src/App.backup.js
+cp .gitignore .gitignore.backup
+echo "
+/* @flow */
+var wrong: string = 0;
+" >> src/App.js
+npm start -- --smoke-test || true
+test -e .flowconfig
+test -d flow-typed
+cat .gitignore | grep flow-typed
+rm src/App.js .gitignore
+cp src/App.backup.js src/App.js
+cp .gitignore.backup .gitignore
+rm src/App.backup.js .gitignore.backup .flowconfig
+rm -rf flow-typed
 
 # ******************************************************************************
 # Test --scripts-version with a version number

From 911bf6d11b1c231ecbfc28dfb5e4364c159e5722 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 19:04:48 +0100
Subject: [PATCH 20/31] Run flow even if init failed

---
 packages/react-dev-utils/FlowTypecheckPlugin.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index 8bbd67b34b2..ff324069a90 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -184,13 +184,14 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
               flowInitializationPromise = initializeFlow(
                 compiler.options.context, this.flowconfig, this.otherFlowTypedDefs
               )
-              .then(() => {
-                flowInitialized = true;
-              }, (e) => {
+              .catch(e => {
                 loaderContext.emitWarning(new Error(
                   'Flow project initialization warning:\n' +
                   e.message
                 ));
+              })
+              .then(() => {
+                flowInitialized = true;
               });
               flowActiveOnProject = true;
             }

From 3b06bf1ce8a87841883919896f8cb08c865d4a7c Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 21:38:02 +0100
Subject: [PATCH 21/31] Remove fbjs ignores now that it's fixed

---
 packages/react-scripts/config/webpack.config.dev.js | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index db8e51f1027..fef412cf5bd 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -231,9 +231,6 @@ module.exports = {
     // Trigger some typechecking if a file matches with an @ flow comment
     new FlowTypecheckPlugin({
       flowconfig: [
-        '[ignore]',
-        '<PROJECT_ROOT>/node_modules/fbjs/.*',
-        '',
         '[libs]',
         './flow-typed'
       ],

From 52e207afd8545009ab08ff5396b009f4c0980932 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 22:38:20 +0100
Subject: [PATCH 22/31] Remove flow-typed lib import (known by default!)

---
 packages/react-scripts/config/webpack.config.dev.js | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index fef412cf5bd..c276a60be70 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -230,10 +230,6 @@ module.exports = {
     new WatchMissingNodeModulesPlugin(paths.appNodeModules),
     // Trigger some typechecking if a file matches with an @ flow comment
     new FlowTypecheckPlugin({
-      flowconfig: [
-        '[libs]',
-        './flow-typed'
-      ],
       otherFlowTypedDefs: {
         jest: "17.0.0"
       }

From c0188d900b5c4b33dd6ab6f0c39195eba83e7be3 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 22:39:45 +0100
Subject: [PATCH 23/31] Remove info about the .flowconfig in the docs

It's now useless
---
 packages/react-scripts/template/README.md | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/packages/react-scripts/template/README.md b/packages/react-scripts/template/README.md
index e3ef399bfc5..6ca7c15be4f 100644
--- a/packages/react-scripts/template/README.md
+++ b/packages/react-scripts/template/README.md
@@ -448,16 +448,6 @@ Flow typing is now supported out of the box. All you have to do is add the `/* @
 want to typecheck. If no `.flowconfig` is present, one will be generated for you. The script will also download type
 definitions from [flow-typed](https://github.com/flowtype/flow-typed) automatically.
 
-If you don't have the auto-generated `.flowconfig` because you had flow setup before, you can copy it from here:
-
-```ini
-[ignore]
-<PROJECT_ROOT>/node_modules/fbjs/.*
-
-[libs]
-./flow-typed
-```
-
 Flow errors will show up alongside eslint errors as you work on your application.
 
 >Note: If your global flow installation version differs from react-scripts's flow version, you may experience slower compilation times while going back and forth between your app and your IDE (that may use your global flow). Ensure you have the same `flow-bin` version [here](https://github.com/facebookincubator/create-react-app/blob/master/packages/react-dev-utils/package.json).

From be43c83abe982dde33612175c79d4a73b63ef1a2 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Mon, 5 Dec 2016 23:33:29 +0100
Subject: [PATCH 24/31] In e2e: assert flow is correctly showing errors

---
 tasks/e2e.sh | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/tasks/e2e.sh b/tasks/e2e.sh
index 7a47d99fef8..5d9d5dbe172 100755
--- a/tasks/e2e.sh
+++ b/tasks/e2e.sh
@@ -159,12 +159,14 @@ cp .gitignore .gitignore.backup
 echo "
 /* @flow */
 var wrong: string = 0;
-" >> src/App.js
-npm start -- --smoke-test || true
+" > src/App.js
+cat src/App.backup.js >> src/App.js
+CI=true npm run build >> errors.log 2>> errors.log || true
+cat errors.log | grep "This type is incompatible with"
 test -e .flowconfig
 test -d flow-typed
 cat .gitignore | grep flow-typed
-rm src/App.js .gitignore
+rm src/App.js .gitignore errors.log
 cp src/App.backup.js src/App.js
 cp .gitignore.backup .gitignore
 rm src/App.backup.js .gitignore.backup .flowconfig
@@ -210,12 +212,13 @@ cp .gitignore .gitignore.backup
 echo "
 /* @flow */
 var wrong: string = 0;
-" >> src/App.js
-npm start -- --smoke-test || true
-test -e .flowconfig
+" > src/App.js
+cat src/App.backup.js >> src/App.js
+CI=true npm run build >> errors.log 2>> errors.log || true
+cat errors.log | grep "This type is incompatible with"
 test -d flow-typed
 cat .gitignore | grep flow-typed
-rm src/App.js .gitignore
+rm src/App.js .gitignore errors.log
 cp src/App.backup.js src/App.js
 cp .gitignore.backup .gitignore
 rm src/App.backup.js .gitignore.backup .flowconfig

From 46829e3f048f16ce9673723f7968e0d37c36a997 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Thu, 8 Dec 2016 17:07:04 +0100
Subject: [PATCH 25/31] Only change gitignore if we create a flowconfig

---
 packages/react-dev-utils/FlowTypecheckPlugin.js | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index ff324069a90..a9fc4672940 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -58,10 +58,10 @@ function writeFileIfDoesNotExist(path, data) {
           if (err) {
             return reject(err);
           }
-          resolve(data);
+          resolve(true);
         });
       } else {
-        resolve(data);
+        resolve(false);
       }
     });
   });
@@ -75,7 +75,7 @@ function writeInFileIfNotPresent(path, contentToAssert, contentToAppend) {
           if (err) {
             return reject(err);
           }
-          resolve(contentToAppend);
+          resolve(true);
         });
       } else {
         fs.readFile(path, (err, existingContent) => {
@@ -87,10 +87,10 @@ function writeInFileIfNotPresent(path, contentToAssert, contentToAppend) {
               if (err) {
                 return reject(err);
               }
-              resolve(contentToAppend);
+              resolve(true);
             });
           } else {
-            resolve(contentToAppend);
+            resolve(false);
           }
         });
       }
@@ -126,8 +126,11 @@ function initializeFlow(projectPath, flowconfig, otherFlowTypedDefs) {
         )) :
         true
     ),
-    writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n')),
-    writeInFileIfNotPresent(gitignorePath, 'flow-typed', 'flow-typed'),
+    writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n'))
+    .then(wroteFlowconfig => wroteFlowconfig ?
+      writeInFileIfNotPresent(gitignorePath, 'flow-typed', 'flow-typed/npm') :
+      false
+    ),
     execOneTime(
       flowTypedPath,
       ['install', '--overwrite', '--flowVersion=' + localVersion],

From 74705ffa9f71251b03bc9d632e4b49da79590e10 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Thu, 8 Dec 2016 18:49:27 +0100
Subject: [PATCH 26/31] Only consider src tests

---
 packages/react-scripts/config/webpack.config.dev.js  |  4 ++--
 packages/react-scripts/config/webpack.config.prod.js | 10 +++++++++-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index 7677b8b5011..f119b6e712f 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -232,8 +232,8 @@ module.exports = {
     // This plugin makes webpack aware of them without emitting them.
     // See https://github.com/facebookincubator/create-react-app/issues/1169
     new WatchTestFilesPlugin([
-      '**/__tests__/**',
-      '**/*.test.js',
+      'src/**/__tests__/**',
+      'src/**/*.test.js',
     ]),
   ],
   // Some libraries import Node modules but don't use them in the browser.
diff --git a/packages/react-scripts/config/webpack.config.prod.js b/packages/react-scripts/config/webpack.config.prod.js
index 71509658eb7..361442f8ee1 100644
--- a/packages/react-scripts/config/webpack.config.prod.js
+++ b/packages/react-scripts/config/webpack.config.prod.js
@@ -16,6 +16,7 @@ var ExtractTextPlugin = require('extract-text-webpack-plugin');
 var ManifestPlugin = require('webpack-manifest-plugin');
 var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
 var SubresourceIntegrityPlugin = require('webpack-subresource-integrity');
+var WatchTestFilesPlugin = require('react-dev-utils/WatchTestFilesPlugin');
 var url = require('url');
 var paths = require('./paths');
 var getClientEnvironment = require('./env');
@@ -277,7 +278,14 @@ module.exports = {
     // Generate and inject subresources hashes in the final `index.html`.
     new SubresourceIntegrityPlugin({
       hashFuncNames: ['sha256', 'sha384']
-    })
+    }),
+    // Tests won't have any linting unless they go through webpack.
+    // This plugin makes webpack aware of them without emitting them.
+    // See https://github.com/facebookincubator/create-react-app/issues/1169
+    new WatchTestFilesPlugin([
+      'src/**/__tests__/**',
+      'src/**/*.test.js',
+    ])
   ],
   // Some libraries import Node modules but don't use them in the browser.
   // Tell Webpack to provide empty mocks for them so importing them works.

From 7489f54e0c5e03880aeaa90c3f8401809d19ca8f Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Fri, 9 Dec 2016 20:07:24 +0100
Subject: [PATCH 27/31] Ignore directories in test glob

---
 packages/react-dev-utils/WatchTestFilesPlugin.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/react-dev-utils/WatchTestFilesPlugin.js b/packages/react-dev-utils/WatchTestFilesPlugin.js
index b7b25fd4713..65e16f76d44 100644
--- a/packages/react-dev-utils/WatchTestFilesPlugin.js
+++ b/packages/react-dev-utils/WatchTestFilesPlugin.js
@@ -18,7 +18,8 @@ function getGlobs(patterns, cwd) {
   return Promise.all(patterns.map(globPattern =>
     computeGlob(globPattern, {
       cwd: cwd,
-      ignore: 'node_modules/**',
+      ignore: 'node_modules/**/*',
+      nodir: true,
     })
   ))
   .then(globLists => [].concat.apply([], globLists))

From 58e82874a773647bb3dccf20ee3a5cb6a820d1f5 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Fri, 9 Dec 2016 20:07:24 +0100
Subject: [PATCH 28/31] Ignore directories in test glob

---
 packages/react-dev-utils/WatchTestFilesPlugin.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/react-dev-utils/WatchTestFilesPlugin.js b/packages/react-dev-utils/WatchTestFilesPlugin.js
index b7b25fd4713..65e16f76d44 100644
--- a/packages/react-dev-utils/WatchTestFilesPlugin.js
+++ b/packages/react-dev-utils/WatchTestFilesPlugin.js
@@ -18,7 +18,8 @@ function getGlobs(patterns, cwd) {
   return Promise.all(patterns.map(globPattern =>
     computeGlob(globPattern, {
       cwd: cwd,
-      ignore: 'node_modules/**',
+      ignore: 'node_modules/**/*',
+      nodir: true,
     })
   ))
   .then(globLists => [].concat.apply([], globLists))

From 3639147051111602a24bc095d6351aebda17a203 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Fri, 9 Dec 2016 20:29:13 +0100
Subject: [PATCH 29/31] Don't reinit flow in a child compilation

---
 packages/react-dev-utils/FlowTypecheckPlugin.js | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index a9fc4672940..f23e6b9e133 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -184,9 +184,11 @@ FlowTypecheckPlugin.prototype.apply = function(compiler) {
         loaderContext.fs.readFile(module.resource, (err, data) => {
           if (data && data.toString().indexOf('@flow') >= 0) {
             if (!flowActiveOnProject) {
-              flowInitializationPromise = initializeFlow(
-                compiler.options.context, this.flowconfig, this.otherFlowTypedDefs
-              )
+              flowInitializationPromise = (!compiler.parentCompilation ?
+                initializeFlow(
+                  compiler.options.context, this.flowconfig, this.otherFlowTypedDefs
+                ) : Promise.resolve()
+              )  
               .catch(e => {
                 loaderContext.emitWarning(new Error(
                   'Flow project initialization warning:\n' +

From 07a556e5b0aad5779edd63d16523d6c86ce2cab7 Mon Sep 17 00:00:00 2001
From: Robin Ricard <ricard.robin@gmail.com>
Date: Fri, 9 Dec 2016 20:53:15 +0100
Subject: [PATCH 30/31] Refine globbing

---
 packages/react-scripts/config/webpack.config.dev.js  | 5 +++--
 packages/react-scripts/config/webpack.config.prod.js | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/packages/react-scripts/config/webpack.config.dev.js b/packages/react-scripts/config/webpack.config.dev.js
index f119b6e712f..2937b5b78e3 100644
--- a/packages/react-scripts/config/webpack.config.dev.js
+++ b/packages/react-scripts/config/webpack.config.dev.js
@@ -232,8 +232,9 @@ module.exports = {
     // This plugin makes webpack aware of them without emitting them.
     // See https://github.com/facebookincubator/create-react-app/issues/1169
     new WatchTestFilesPlugin([
-      'src/**/__tests__/**',
-      'src/**/*.test.js',
+      'src/**/__tests__/**/*',
+      'src/**/*.test.*',
+      '__tests__/**/*',
     ]),
   ],
   // Some libraries import Node modules but don't use them in the browser.
diff --git a/packages/react-scripts/config/webpack.config.prod.js b/packages/react-scripts/config/webpack.config.prod.js
index 361442f8ee1..b0426612df2 100644
--- a/packages/react-scripts/config/webpack.config.prod.js
+++ b/packages/react-scripts/config/webpack.config.prod.js
@@ -283,8 +283,9 @@ module.exports = {
     // This plugin makes webpack aware of them without emitting them.
     // See https://github.com/facebookincubator/create-react-app/issues/1169
     new WatchTestFilesPlugin([
-      'src/**/__tests__/**',
-      'src/**/*.test.js',
+      'src/**/__tests__/**/*',
+      'src/**/*.test.*',
+      '__tests__/**/*',
     ])
   ],
   // Some libraries import Node modules but don't use them in the browser.

From 1e21de786f0f7977658e3c7333830b467728eafb Mon Sep 17 00:00:00 2001
From: Gregor Weber <gregorwbr@gmail.com>
Date: Sat, 18 Mar 2017 21:06:31 +0100
Subject: [PATCH 31/31] Don't put flow-typed on gitignore

---
 packages/react-dev-utils/FlowTypecheckPlugin.js | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/packages/react-dev-utils/FlowTypecheckPlugin.js b/packages/react-dev-utils/FlowTypecheckPlugin.js
index f23e6b9e133..a6b9e020f1b 100644
--- a/packages/react-dev-utils/FlowTypecheckPlugin.js
+++ b/packages/react-dev-utils/FlowTypecheckPlugin.js
@@ -108,8 +108,6 @@ function getFlowVersion(options) {
 }
 
 function initializeFlow(projectPath, flowconfig, otherFlowTypedDefs) {
-  const flowconfigPath = path.join(projectPath, '.flowconfig');
-  const gitignorePath = path.join(projectPath, '.gitignore');
   return getFlowVersion().then(localVersion => Promise.all([
     getFlowVersion({global: true}).catch(() => localVersion)
     .then(globalVersion =>
@@ -126,11 +124,6 @@ function initializeFlow(projectPath, flowconfig, otherFlowTypedDefs) {
         )) :
         true
     ),
-    writeFileIfDoesNotExist(flowconfigPath, flowconfig.join('\n'))
-    .then(wroteFlowconfig => wroteFlowconfig ?
-      writeInFileIfNotPresent(gitignorePath, 'flow-typed', 'flow-typed/npm') :
-      false
-    ),
     execOneTime(
       flowTypedPath,
       ['install', '--overwrite', '--flowVersion=' + localVersion],