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/angular-api-package/index.js

@@ -119,6 +119,17 @@ module.exports = new Package('angular-api', [basePackage, typeScriptPackage])
     addNotYetDocumentedProperty.docTypes = API_DOC_TYPES;
   })
 
+  .config(function(mergeDecoratorDocs) {
+    mergeDecoratorDocs.propertiesToMerge = [
+      'shortDescription',
+      'description',
+      'security',
+      'deprecated',
+      'see',
+      'usageNotes',
+    ];
+  })
+
   .config(function(checkContentRules, EXPORT_DOC_TYPES) {
     // Min length rules
     const createMinLengthRule = require('./content-rules/minLength');

aio/tools/transforms/angular-api-package/processors/mergeDecoratorDocs.js

@@ -1,3 +1,5 @@
+const {mergeProperties} = require('../../helpers/utils');
+
 /**
  * Decorators in the Angular code base are made up from three code items:
  *
@@ -47,6 +49,7 @@ module.exports = function mergeDecoratorDocs(log) {
   return {
     $runAfter: ['processing-docs'],
     $runBefore: ['docs-processed'],
+    propertiesToMerge: [],
     makeDecoratorCalls: [
       {type: '', description: 'toplevel', functionName: 'makeDecorator'},
       {type: 'Prop', description: 'property', functionName: 'makePropDecorator'},
@@ -55,6 +58,7 @@ module.exports = function mergeDecoratorDocs(log) {
     $process: function(docs) {
 
       var makeDecoratorCalls = this.makeDecoratorCalls;
+      var propertiesToMerge = this.propertiesToMerge;
       var docsToMerge = Object.create(null);
 
       docs.forEach(function(doc) {
@@ -88,9 +92,9 @@ module.exports = function mergeDecoratorDocs(log) {
           log.debug(
               'mergeDecoratorDocs: merging', doc.name, 'into', decoratorDoc.name,
               callMember.description.substring(0, 50));
+
           // Merge the documentation found in this call signature into the original decorator
-          decoratorDoc.description = callMember.description;
-          decoratorDoc.usageNotes = callMember.usageNotes;
+          mergeProperties(decoratorDoc, callMember, propertiesToMerge);
 
           // remove doc from its module doc's exports
           doc.moduleDoc.exports =

aio/tools/transforms/angular-api-package/processors/mergeDecoratorDocs.spec.js

@@ -9,17 +9,21 @@ describe('mergeDecoratorDocs processor', () => {
     const injector = dgeni.configureInjector();
     processor = injector.get('mergeDecoratorDocs');
 
+    // Note that we do not include usageNotes in the tests.
+    processor.propertiesToMerge = ['description', 'shortDescription'];
+
     moduleDoc = {};
 
     decoratorDoc = {
       name: 'Component',
       docType: 'const',
-      description: 'A description of the metadata for the Component decorator',
+      shortDescription: 'decorator - short description',
+      description: 'decorator - description',
       symbol: {
         valueDeclaration: { initializer: { expression: { text: 'makeDecorator' }, arguments: [{ text: 'X' }] } }
       },
       members: [
-        { name: 'templateUrl', description: 'A description of the templateUrl property' }
+        { name: 'templateUrl', description: 'templateUrl - description' }
       ],
       moduleDoc
     };
@@ -27,15 +31,15 @@ describe('mergeDecoratorDocs processor', () => {
     metadataDoc = {
       name: 'ComponentDecorator',
       docType: 'interface',
-      description: 'A description of the interface for the call signature for the Component decorator',
+      description: 'call interface - description',
       members: [
         {
           isCallMember: true,
-          description: 'The actual description of the call signature',
-          usageNotes: 'Use it like this...'
+          description: 'call interface - call member - description',
+          usageNotes: 'call interface - call member - usageNotes',
         },
         {
-          description: 'Some other member'
+          description: 'call interface - non call member - description'
         }
       ],
       moduleDoc
@@ -65,10 +69,13 @@ describe('mergeDecoratorDocs processor', () => {
     expect(decoratorDoc.decoratorType).toEqual('X');
   });
 
-  it('should copy across properties from the call signature doc', () => {
+  it('should copy across specified properties from the call signature doc', () => {
     processor.$process([decoratorDoc, metadataDoc, otherDoc]);
-    expect(decoratorDoc.description).toEqual('The actual description of the call signature');
-    expect(decoratorDoc.usageNotes).toEqual('Use it like this...');
+    expect(decoratorDoc.description).toEqual('call interface - call member - description');
+    // Since usageNotes is not in `propertiesToMerge` it will not get copied over in these tests.
+    expect(decoratorDoc.usageNotes).toBeUndefined();
+    // Since `shortDescription` does not exist on the call-member this will not get overridden.
+    expect(decoratorDoc.shortDescription).toEqual('decorator - short description');
   });
 
   it('should remove the metadataDoc from the module exports', () => {