build(aio): ensure the correct decorator properties are merged (#24289)

Previously only the `description` and `usageNotes` were being copied over
from the call-member of the decorator interface. Important properties such
as `shortDescription` were missed.

These are now added and the code has been refactored to make it simpler and
clearer to update which properties get copied as the requirements change.

PR Close #24289

aio/tools/transforms/helpers/utils.js

@@ -96,5 +96,19 @@ module.exports = {
       attrMap[key] === false ? '' :
       attrMap[key] === true ? ` ${key}` :
       ` ${key}="${attrMap[key].replace(/"/g, '"')}"`).join('');
-  }
+  },
+
+  /**
+   * Merge the specified properties from the source to the target document
+   * @param {Document} target The document to receive the properties from the source
+   * @param {Document} source The document from which to get the properties to merge
+   * @param {string[]} properties A collection of the names of the properties to merge
+   */
+  mergeProperties(target, source, properties) {
+    properties.forEach(property => {
+      if (source.hasOwnProperty(property)) {
+        target[property] = source[property];
+      }
+    });
+  },
 };

aio/tools/transforms/helpers/utils.spec.js

@@ -1,4 +1,4 @@
-const { mapObject, parseAttributes, renderAttributes } = require('./utils');
+const { mergeProperties, mapObject, parseAttributes, renderAttributes } = require('./utils');
 
 describe('utils', () => {
   describe('mapObject', () => {
@@ -96,4 +96,34 @@ describe('utils', () => {
       expect(renderAttributes({ })).toEqual('');
     });
   });
+
+  describe('mergeProperties', () => {
+    it('should write specified properties from the source to the target', () => {
+      const source = { a: 1, b: 2, c: 3 };
+      const target = { };
+      mergeProperties(target, source, ['a', 'b']);
+      expect(target).toEqual({ a: 1, b: 2 });
+    });
+
+    it('should not overwrite target properties that are not specified', () => {
+      const source = { a: 1, b: 2, c: 3 };
+      const target = { b: 10 };
+      mergeProperties(target, source, ['a']);
+      expect(target).toEqual({ a: 1, b: 10 });
+    });
+
+    it('should not overwrite target properties that are specified but do not exist in the source', () => {
+      const source = { a: 1 };
+      const target = { b: 10 };
+      mergeProperties(target, source, ['a', 'b']);
+      expect(target).toEqual({ a: 1, b: 10 });
+    });
+
+    it('should overwrite target properties even if they are `undefined` in the source', () => {
+      const source = { a: undefined };
+      const target = { a: 10 };
+      mergeProperties(target, source, ['a']);
+      expect(target).toEqual({ a: undefined });
+    });
+  });
 });