feat(infrastructure): add verify pkg main to dist script (#320)

scripts/release/pre-release.sh

@@ -56,6 +56,10 @@ log "Moving built assets to package directories..."
 node scripts/release/cp-pkgs.js
 echo ""
 
+log "Verifying that all packages are correctly pointing main to dist..."
+node scripts/release/verify-pkg-main.js
+echo ""
+
 log "Pre-release steps done! Next, you should run:" \
   "\$(npm bin)/lerna publish --skip-git"
 echo ""

scripts/release/verify-pkg-main.js

@@ -0,0 +1,67 @@
+/*
+ The MIT License
+
+ Copyright (c) 2018 Google, Inc.
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE.
+*/
+
+const fs = require('fs');
+const path = require('path');
+const {sync: globSync} = require('glob');
+
+const isValidCwd = fs.existsSync('packages');
+
+if (!isValidCwd) {
+  console.error(
+    'Invalid CWD. Please ensure you are running this from the root of the repo, and that you have run ' +
+    '`npm run dist` and `node scripts/cp-pkgs.js`'
+  );
+  process.exit(1);
+}
+
+let invalidMains = 0;
+globSync('packages/*/package.json').forEach((jsonPath) => {
+  const packageInfo = JSON.parse(fs.readFileSync(jsonPath));
+  if (!packageInfo.main) {
+    return;
+  }
+
+  const mainPath = path.join(path.dirname(jsonPath), packageInfo.main);
+  let isInvalid = false;
+  if (mainPath.indexOf('dist') < 0) {
+    isInvalid = true;
+    console.error(`${jsonPath} main property does not reference a file under dist`);
+  }
+  if (!fs.existsSync(mainPath)) {
+    isInvalid = true;
+    console.error(`${jsonPath} main property points to nonexistent ${mainPath}`);
+  }
+
+  if (isInvalid) {
+    // Multiple checks could have failed, but only increment the counter once for one package.
+    invalidMains++;
+  }
+});
+
+if (invalidMains > 0) {
+  console.error(`${invalidMains} incorrect main property values found; please fix.`);
+} else {
+  console.log('Success: All packages with main properties reference valid files under dist!');
+}