build(docs-infra): add more checks to verify contributors.json data (#40369)

This commit adds extra steps to verify contributors.json data, such as checking `lead` and `mentor` field as well as
making sure the list is sorted alphabetically.

PR Close #40369

aio/scripts/contributors/validate-data.js

@@ -8,6 +8,7 @@ const {join, resolve} = require('path');
 const CONTENT_DIR = resolve(__dirname, '../../content');
 const IMAGES_DIR = join(CONTENT_DIR, 'images/bios');
 const CONTRIBUTORS_PATH = join(CONTENT_DIR, 'marketing/contributors.json');
+const EXISTING_GROUPS = new Set(['Angular', 'GDE', 'Collaborators']);
 
 // Run
 _main();
@@ -15,6 +16,8 @@ _main();
 // Functions - Definitions
 function _main() {
   const contributors = JSON.parse(readFileSync(CONTRIBUTORS_PATH, 'utf8'));
+
+  // Check that there are no missing images.
   const expectedImages = Object.keys(contributors)
       .filter(key => !!contributors[key].picture)
       .map(key => join(IMAGES_DIR, contributors[key].picture));
@@ -25,4 +28,33 @@ function _main() {
         'The following pictures are referenced in \'contributors.json\' but do not exist:' +
         missingImages.map(path => `\n  - ${path}`).join(''));
   }
+
+  // Verify that all keys are sorted alphabetically
+  const keys = Object.keys(contributors);
+  for (let i = 1; i < keys.length; i++) {
+    if (keys[i - 1].toLowerCase() > keys[i].toLowerCase()) {
+      throw new Error(
+        `The following keys in 'contributors.json' are not in alphabetical order: '${keys[i - 1]}' and '${keys[i]}'.`
+      );
+    }
+  }
+
+  Object.entries(contributors).forEach(([key, entry]) => {
+    // Make sure `lead` and `mentor` fields refer to existing entries
+    if (entry.lead && !contributors[entry.lead]) {
+      throw new Error(`The '${key}' entry contains 'lead' field, but it refers to non-existing entry ('${entry.lead}').`);
+    }
+    if (entry.mentor && !contributors[entry.mentor]) {
+      throw new Error(`The '${key}' entry contains 'mentor' field, but it refers to non-existing entry ('${entry.mentor}').`);
+    }
+
+    // Verify that `groups` field is always present and contains existing groups
+    if (!entry.groups || !Array.isArray(entry.groups) || entry.groups.length === 0) {
+      throw new Error(`The 'groups' field should be defined as a non-empty array (entry: '${key}').`);
+    }
+    if (entry.groups.some(group => !EXISTING_GROUPS.has(group))) {
+      throw new Error(`The '${key}' entry contains 'groups' field with unknown values ` +
+        `(groups: ${JSON.stringify(entry.groups)}, known values: ${JSON.stringify(Array.from(EXISTING_GROUPS))}).`);
+    }
+  });
 }