test(docs-infra): add script for verifying all guides/examples/images have owners (#28597)

It is useful for manually checking that all guides/examples/images have
owners in `.github/CODEOWNERS`, but is not used for automatic
verification (e.g. on CI) for now.

PR Close #28597

aio/scripts/verify-guide-codeownership.js

@@ -0,0 +1,87 @@
+'use strict';
+
+// Imports
+const fs = require('fs');
+const path = require('path');
+
+// Constants
+const PROJECT_ROOT_DIR = path.resolve(__dirname, '../..');
+const CODEOWNERS_PATH = path.resolve(PROJECT_ROOT_DIR, '.github/CODEOWNERS');
+const AIO_CONTENT_DIR = path.resolve(PROJECT_ROOT_DIR, 'aio/content');
+const AIO_GUIDES_DIR = path.resolve(AIO_CONTENT_DIR, 'guide');
+const AIO_GUIDE_IMAGES_DIR = path.resolve(AIO_CONTENT_DIR, 'images/guide');
+const AIO_GUIDE_EXAMPLES_DIR = path.resolve(AIO_CONTENT_DIR, 'examples');
+
+// Run
+_main();
+
+// Functions - Definitions
+function _main() {
+  const {guides: acGuidePaths, images: acGuideImagesPaths, examples: acExamplePaths} = getPathsFromAioContent();
+  const {guides: coGuidePaths, images: coGuideImagesPaths, examples: coExamplePaths} = getPathsFromCodeowners();
+
+  const guidesDiff = arrayDiff(acGuidePaths, coGuidePaths);
+  const imagesDiff = arrayDiff(acGuideImagesPaths, coGuideImagesPaths);
+  const examplesDiff = arrayDiff(acExamplePaths, coExamplePaths);
+  const hasDiff = !!(guidesDiff.diffCount || imagesDiff.diffCount || examplesDiff.diffCount);
+
+  if (hasDiff) {
+    const expectedGuidesSrc = path.relative(PROJECT_ROOT_DIR, AIO_GUIDES_DIR);
+    const expectedImagesSrc = path.relative(PROJECT_ROOT_DIR, AIO_GUIDE_IMAGES_DIR);
+    const expectedExamplesSrc = path.relative(PROJECT_ROOT_DIR, AIO_GUIDE_EXAMPLES_DIR);
+    const actualSrc = path.relative(PROJECT_ROOT_DIR, CODEOWNERS_PATH);
+
+    reportDiff(guidesDiff, expectedGuidesSrc, actualSrc);
+    reportDiff(imagesDiff, expectedImagesSrc, actualSrc);
+    reportDiff(examplesDiff, expectedExamplesSrc, actualSrc);
+  }
+
+  process.exit(hasDiff ? 1 : 0);
+}
+
+function arrayDiff(expected, actual) {
+  const missing = expected.filter(x => !actual.includes(x)).sort();
+  const extra = actual.filter(x => !expected.includes(x)).sort();
+
+  return {missing, extra, diffCount: missing.length + extra.length};
+}
+
+function getPathsFromAioContent() {
+  return {
+    guides: fs.readdirSync(AIO_GUIDES_DIR),
+    images: fs.readdirSync(AIO_GUIDE_IMAGES_DIR),
+    examples: fs.readdirSync(AIO_GUIDE_EXAMPLES_DIR).
+      filter(name => fs.statSync(`${AIO_GUIDE_EXAMPLES_DIR}/${name}`).isDirectory()),
+  };
+}
+
+function getPathsFromCodeowners() {
+  const guidesOrImagesPathRe = /^\/aio\/content\/(?:(images\/)?guide|(examples))\/([^\s/]+)/;
+
+  return fs.
+    readFileSync(CODEOWNERS_PATH, 'utf8').
+    split('\n').
+    map(l => l.trim().match(guidesOrImagesPathRe)).
+    filter(m => m).
+    reduce((aggr, [, isImage, isExample, path]) => {
+      const list = isExample ? aggr.examples :
+                   isImage   ? aggr.images :
+                               aggr.guides;
+      list.push(path);
+      return aggr;
+    }, {guides: [], images: [], examples: []});
+}
+
+function reportDiff(diff, expectedSrc, actualSrc) {
+  if (diff.missing.length) {
+    console.error(
+        `\nEntries in '${expectedSrc}' but not in '${actualSrc}':\n` +
+        diff.missing.map(x => `  - ${x}`).join('\n'));
+  }
+
+  if (diff.extra.length) {
+    console.error(
+        `\nEntries in '${actualSrc}' but not in '${expectedSrc}':\n` +
+        diff.extra.map(x => `  - ${x}`).join('\n'));
+  }
+}