repl: persist in plain text, save to home tmp directory by default

.eslintrc

@@ -10,6 +10,8 @@ ecmaFeatures:
   generators: true
   forOf: true
   objectLiteralShorthandProperties: true
+  objectLiteralShorthandMethods: true
+  classes: true
 
 rules:
   # Possible Errors

doc/api/repl.markdown

@@ -29,23 +29,38 @@ For example, you could add this to your bashrc file:
 
     alias iojs="env NODE_NO_READLINE=1 rlwrap iojs"
 
+### Persistent History
+
+By default, the REPL will persist history between `iojs` REPL sessions by saving
+to a `.node_repl_history` file in the user's home directory. This can be
+disabled by setting the environment variable `NODE_REPL_HISTORY=""`.
+
+Previously in io.js v2.x, REPL history was controlled by using a
+`NODE_REPL_HISTORY_FILE` environment variable, and the history was saved in JSON
+format. This variable has now been deprecated, and your REPL history will
+automatically be converted to using plain text. The new file will be saved to
+either your home directory, or a directory defined by the `NODE_REPL_HISTORY`
+variable, as documented below.
+
+### Environment Variable Options
+
 The built-in repl (invoked by running `iojs` or `iojs -i`) may be controlled
 via the following environment variables:
 
- - `NODE_REPL_HISTORY_FILE` - if given, must be a path to a user-writable,
-   user-readable file. When a valid path is given, persistent history support
-   is enabled: REPL history will persist across `iojs` repl sessions.
- - `NODE_REPL_HISTORY_SIZE` - defaults to `1000`. In conjunction with
-   `NODE_REPL_HISTORY_FILE`, controls how many lines of history will be
-   persisted. Must be a positive number.
+ - `NODE_REPL_HISTORY` - When a valid path is given, persistent REPL history
+   will be saved to the specified file rather than `.node_repl_history` in the
+   user's home directory. Setting this value to `""` will disable persistent
+   REPL history.
+ - `NODE_REPL_HISTORY_SIZE` - defaults to `1000`. Controls how many lines of
+   history will be persisted if history is available. Must be a positive number.
  - `NODE_REPL_MODE` - may be any of `sloppy`, `strict`, or `magic`. Defaults
    to `magic`, which will automatically run "strict mode only" statements in
    strict mode.
 
 ## repl.start(options)
 
-Returns and starts a `REPLServer` instance, that inherits from 
-[Readline Interface][]. Accepts an "options" Object that takes 
+Returns and starts a `REPLServer` instance, that inherits from
+[Readline Interface][]. Accepts an "options" Object that takes
 the following values:
 
  - `prompt` - the prompt and `stream` for all I/O. Defaults to `> `.

lib/internal/repl.js

@@ -3,6 +3,9 @@
 const Interface = require('readline').Interface;
 const REPL = require('repl');
 const path = require('path');
+const fs = require('fs');
+const os = require('os');
+const debug = require('util').debuglog('repl');
 
 module.exports = Object.create(REPL);
 module.exports.createInternalRepl = createRepl;
@@ -17,8 +20,12 @@ function replStart() {
   return REPL.start.apply(REPL, arguments);
 }
 
-function createRepl(env, cb) {
-  const opts = {
+function createRepl(env, opts, cb) {
+  if (typeof opts === 'function') {
+    cb = opts;
+    opts = null;
+  }
+  opts = opts || {
     ignoreUndefined: false,
     terminal: process.stdout.isTTY,
     useGlobal: true
@@ -51,15 +58,29 @@ function createRepl(env, cb) {
   }
 
   const repl = REPL.start(opts);
-  if (opts.terminal && env.NODE_REPL_HISTORY_FILE) {
-    return setupHistory(repl, env.NODE_REPL_HISTORY_FILE, cb);
+  if (opts.terminal && env.NODE_REPL_HISTORY !== '') {
+    return setupHistory(repl, env.NODE_REPL_HISTORY,
+                        env.NODE_REPL_HISTORY_FILE, cb);
   }
   repl._historyPrev = _replHistoryMessage;
   cb(null, repl);
 }
 
-function setupHistory(repl, historyPath, ready) {
-  const fs = require('fs');
+function setupHistory(repl, historyPath, oldHistoryPath, ready) {
+  if (!historyPath) {
+    try {
+      historyPath = path.join(os.homedir(), '.node_repl_history');
+    } catch (err) {
+      repl._writeToOutput('\nError: Could not get the home directory.\n' +
+                          'REPL session history will not be persisted.\n');
+      repl._refreshLine();
+
+      debug(err.stack);
+      repl._historyPrev = _replHistoryMessage;
+      return ready(null, repl);
+    }
+  }
+
   var timer = null;
   var writing = false;
   var pending = false;
@@ -86,15 +107,25 @@ function setupHistory(repl, historyPath, ready) {
     }
 
     if (data) {
+      repl.history = data.split(/[\n\r]+/).slice(-repl.historySize);
+    } else if (oldHistoryPath) {
+      // Grab data from the older pre-v3.0 JSON NODE_REPL_HISTORY_FILE format.
+      repl._writeToOutput(
+          '\nConverting old JSON repl history to line-separated history.\n' +
+          `The new repl history file can be found at ${historyPath}.\n`);
+      repl._refreshLine();
+
       try {
-        repl.history = JSON.parse(data);
+        repl.history = JSON.parse(fs.readFileSync(oldHistoryPath, 'utf8'));
         if (!Array.isArray(repl.history)) {
           throw new Error('Expected array, got ' + typeof repl.history);
         }
-        repl.history.slice(-repl.historySize);
+
+        repl.history = repl.history.slice(-repl.historySize);
+
       } catch (err) {
         return ready(
-            new Error(`Could not parse history data in ${historyPath}.`));
+            new Error(`Could not parse history data in ${oldHistoryPath}.`));
       }
     }
 
@@ -134,7 +165,7 @@ function setupHistory(repl, historyPath, ready) {
       return;
     }
     writing = true;
-    const historyData = JSON.stringify(repl.history, null, 2);
+    const historyData = repl.history.join(os.EOL);
     fs.write(repl._historyHandle, historyData, 0, 'utf8', onwritten);
   }
 
@@ -157,7 +188,7 @@ function _replHistoryMessage() {
   if (this.history.length === 0) {
     this._writeToOutput(
         '\nPersistent history support disabled. ' +
-        'Set the NODE_REPL_HISTORY_FILE environment variable to ' +
+        'Set the NODE_REPL_HISTORY environment\nvariable to ' +
         'a valid, user-writable path to enable.\n'
     );
     this._refreshLine();

test/fixtures/.node_repl_history

@@ -0,0 +1,2 @@
+'you look fabulous today'
+'Stay Fresh~'

test/fixtures/old-repl-history-file.json

@@ -0,0 +1,4 @@
+[
+  "'=^.^='",
+  "'hello world'"
+]

test/sequential/test-repl-persistent-history.js

@@ -0,0 +1,193 @@
+'use strict';
+
+// Flags: --expose-internals
+
+const common = require('../common');
+const stream = require('stream');
+const REPL = require('internal/repl');
+const assert = require('assert');
+const fs = require('fs');
+const util = require('util');
+const path = require('path');
+const os = require('os');
+
+common.refreshTmpDir();
+
+// Mock os.homedir()
+os.homedir = function() {
+  return common.tmpDir;
+};
+
+// Create an input stream specialized for testing an array of actions
+class ActionStream extends stream.Stream {
+  run(data) {
+    const _iter = data[Symbol.iterator]();
+    const self = this;
+
+    function doAction() {
+      const next = _iter.next();
+      if (next.done) {
+        // Close the repl. Note that it must have a clean prompt to do so.
+        setImmediate(function() {
+          self.emit('keypress', '', { ctrl: true, name: 'd' });
+        });
+        return;
+      }
+      const action = next.value;
+
+      if (typeof action === 'object') {
+        self.emit('keypress', '', action);
+      } else {
+        self.emit('data', action + '\n');
+      }
+      setImmediate(doAction);
+    }
+    setImmediate(doAction);
+  }
+  resume() {}
+  pause() {}
+}
+ActionStream.prototype.readable = true;
+
+
+// Mock keys
+const UP = { name: 'up' };
+const ENTER = { name: 'enter' };
+const CLEAR = { ctrl: true, name: 'u' };
+// Common message bits
+const prompt = '> ';
+const replDisabled = '\nPersistent history support disabled. Set the ' +
+                     'NODE_REPL_HISTORY environment\nvariable to a valid, ' +
+                     'user-writable path to enable.\n';
+const convertMsg = '\nConverting old JSON repl history to line-separated ' +
+                   'history.\nThe new repl history file can be found at ' +
+                   path.join(common.tmpDir, '.node_repl_history') + '.\n';
+const homedirErr = '\nError: Could not get the home directory.\n' +
+                   'REPL session history will not be persisted.\n';
+// File paths
+const fixtures = path.join(common.testDir, 'fixtures');
+const historyFixturePath = path.join(fixtures, '.node_repl_history');
+const historyPath = path.join(common.tmpDir, '.fixture_copy_repl_history');
+const oldHistoryPath = path.join(fixtures, 'old-repl-history-file.json');
+
+
+const tests = [{
+  env: { NODE_REPL_HISTORY: '' },
+  test: [UP],
+  expected: [prompt, replDisabled, prompt]
+},
+{
+  env: { NODE_REPL_HISTORY: '',
+         NODE_REPL_HISTORY_FILE: oldHistoryPath },
+  test: [UP],
+  expected: [prompt, replDisabled, prompt]
+},
+{
+  env: { NODE_REPL_HISTORY: historyPath },
+  test: [UP, CLEAR],
+  expected: [prompt, prompt + '\'you look fabulous today\'', prompt]
+},
+{
+  env: { NODE_REPL_HISTORY: historyPath,
+         NODE_REPL_HISTORY_FILE: oldHistoryPath },
+  test: [UP, CLEAR],
+  expected: [prompt, prompt + '\'you look fabulous today\'', prompt]
+},
+{
+  env: { NODE_REPL_HISTORY: historyPath,
+         NODE_REPL_HISTORY_FILE: '' },
+  test: [UP, CLEAR],
+  expected: [prompt, prompt + '\'you look fabulous today\'', prompt]
+},
+{
+  env: {},
+  test: [UP],
+  expected: [prompt]
+},
+{
+  env: { NODE_REPL_HISTORY_FILE: oldHistoryPath },
+  test: [UP, CLEAR, '\'42\'', ENTER/*, function(cb) {
+    // XXX(Fishrock123) Allow the REPL to save to disk.
+    // There isn't a way to do this programmatically right now.
+    setTimeout(cb, 50);
+  }*/],
+  expected: [prompt, convertMsg, prompt, prompt + '\'=^.^=\'', prompt, '\'',
+             '4', '2', '\'', '\'42\'\n', prompt, prompt],
+  after: function ensureHistoryFixture() {
+    // XXX(Fishrock123) Make sure nothing weird happened to our fixture
+    //  or it's temporary copy.
+    // Sometimes this test used to erase the fixture and I'm not sure why.
+    const history = fs.readFileSync(historyFixturePath, 'utf8');
+    assert.strictEqual(history,
+                       '\'you look fabulous today\'\n\'Stay Fresh~\'\n');
+    const historyCopy = fs.readFileSync(historyPath, 'utf8');
+    assert.strictEqual(historyCopy, '\'you look fabulous today\'' + os.EOL +
+                                    '\'Stay Fresh~\'' + os.EOL);
+  }
+},
+{
+  env: {},
+  test: [UP, UP, ENTER],
+  expected: [prompt, prompt + '\'42\'', prompt + '\'=^.^=\'', '\'=^.^=\'\n',
+             prompt]
+},
+{ // Make sure this is always the last test, since we change os.homedir()
+  before: function mockHomedirFailure() {
+    // Mock os.homedir() failure
+    os.homedir = function() {
+      throw new Error('os.homedir() failure');
+    };
+  },
+  env: {},
+  test: [UP],
+  expected: [prompt, homedirErr, prompt, replDisabled, prompt]
+}];
+
+
+// Copy our fixture to the tmp directory
+fs.createReadStream(historyFixturePath)
+  .pipe(fs.createWriteStream(historyPath)).on('unpipe', runTest);
+
+function runTest() {
+  const opts = tests.shift();
+  if (!opts) return; // All done
+
+  const env = opts.env;
+  const test = opts.test;
+  const expected = opts.expected;
+  const after = opts.after;
+  const before = opts.before;
+
+  if (before) before();
+
+  REPL.createInternalRepl(env, {
+    input: new ActionStream(),
+    output: new stream.Writable({
+      write(chunk, _, next) {
+        const output = chunk.toString();
+
+        // Ignore escapes and blank lines
+        if (output.charCodeAt(0) === 27 || /^[\r\n]+$/.test(output))
+          return next();
+
+        assert.strictEqual(output, expected.shift());
+        next();
+      }
+    }),
+    prompt: prompt,
+    useColors: false,
+    terminal: true
+  }, function(err, repl) {
+    if (err) throw err;
+
+    if (after) repl.on('close', after);
+
+    repl.on('close', function() {
+      // Ensure everything that we expected was output
+      assert.strictEqual(expected.length, 0);
+      setImmediate(runTest);
+    });
+
+    repl.inputStream.run(test);
+  });
+}