feat(jsdoc-doclet): emit events when certain doclet properties change

packages/jsdoc-doclet/lib/augment.js

@@ -17,9 +17,8 @@
  * Provides methods for augmenting the parse results based on their content.
  */
 import { name } from '@jsdoc/core';
-import _ from 'lodash';
 
-import { combineDoclets } from './doclet.js';
+import { combineDoclets, Doclet } from './doclet.js';
 
 const { fromParts, SCOPE, toParts } = name;
 
@@ -37,7 +36,7 @@ function mapDependencies(index, propertyName) {
       if (kinds.includes(doc.kind)) {
         dependencies[indexName] = {};
         if (Object.hasOwn(doc, propertyName)) {
-          len = doc[propertyName].length;
+          len = doc[propertyName]?.length;
           for (let j = 0; j < len; j++) {
             dependencies[indexName][doc[propertyName][j]] = true;
           }
@@ -382,7 +381,8 @@ function getMixedInAdditions(mixinDoclets, allDoclets, { documented, memberof })
             continue;
           }
 
-          mixedDoclet = _.cloneDeep(mixedDoclets[k]);
+          mixedDoclet = new Doclet('', null, mixedDoclets[k].dependencies);
+          mixedDoclet = combineDoclets(mixedDoclets[k], mixedDoclet);
 
           updateMixes(mixedDoclet, mixedDoclet.longname);
           mixedDoclet.mixed = true;
@@ -411,9 +411,7 @@ function updateImplements(implDoclets, implementedLongname) {
   }
 
   implDoclets.forEach((implDoclet) => {
-    if (!Object.hasOwn(implDoclet, 'implements')) {
-      implDoclet.implements = [];
-    }
+    implDoclet.implements ??= [];
 
     if (!implDoclet.implements.includes(implementedLongname)) {
       implDoclet.implements.push(implementedLongname);

packages/jsdoc-doclet/lib/borrow.js

@@ -22,7 +22,7 @@ import _ from 'lodash';
 const { SCOPE } = name;
 
 function cloneBorrowedDoclets({ borrowed, longname }, doclets) {
-  borrowed.forEach(({ from, as }) => {
+  borrowed?.forEach(({ from, as }) => {
     const borrowedDoclets = doclets.index.longname[from];
     let borrowedAs = as || from;
     let parts;
@@ -60,7 +60,7 @@ function cloneBorrowedDoclets({ borrowed, longname }, doclets) {
 export function resolveBorrows(doclets) {
   for (let doclet of doclets.index.borrowed) {
     cloneBorrowedDoclets(doclet, doclets);
-    delete doclet.borrowed;
+    doclet.borrowed = undefined;
   }
 
   doclets.index.borrowed = [];

packages/jsdoc-doclet/lib/doclet.js

@@ -40,6 +40,21 @@ const DEFAULT_SCOPE = SCOPE.NAMES.STATIC;
 // TODO: `class` should be on this list, right? What are the implications of adding it?
 const GLOBAL_KINDS = ['constant', 'function', 'member', 'typedef'];
 
+export const WATCHABLE_PROPS = [
+  'access',
+  'augments',
+  'borrowed',
+  'ignore',
+  'implements',
+  'kind',
+  'listens',
+  'longname',
+  'memberof',
+  'mixes',
+  'scope',
+  'undocumented',
+];
+
 function fakeMeta(node) {
   return {
     type: node ? node.type : null,
@@ -242,7 +257,7 @@ function resolve(doclet) {
   if (doclet.scope === SCOPE.NAMES.GLOBAL) {
     // via @global tag?
     doclet.setLongname(doclet.name);
-    delete doclet.memberof;
+    doclet.memberof = undefined;
   } else if (about.scope) {
     if (about.memberof === LONGNAMES.GLOBAL) {
       // via @memberof <global> ?
@@ -375,6 +390,7 @@ function copySpecificProperties(primary, secondary, target, include) {
 export class Doclet {
   #accessConfig;
   #dictionary;
+  #eventBus;
 
   /**
    * Create a doclet.
@@ -389,12 +405,31 @@ export class Doclet {
     meta = meta || {};
     this.#accessConfig = dependencies.get('config')?.opts?.access ?? [];
     this.#dictionary = dependencies.get('tags');
-    /** The original text of the comment from the source code. */
-    this.comment = docletSrc;
+    this.#eventBus = dependencies.get('eventBus');
+
     Object.defineProperty(this, 'dependencies', {
       enumerable: false,
       value: dependencies,
     });
+    Object.defineProperty(this, 'watchableProps', {
+      enumerable: false,
+      value: {},
+      writable: true,
+    });
+    for (const prop of WATCHABLE_PROPS) {
+      Object.defineProperty(this, prop, {
+        enumerable: true,
+        get() {
+          return this.watchableProps[prop];
+        },
+        set(newValue) {
+          this.#setWatchableProperty(prop, newValue);
+        },
+      });
+    }
+
+    /** The original text of the comment from the source code. */
+    this.comment = docletSrc;
     this.setMeta(meta);
 
     docletSrc = unwrap(docletSrc);
@@ -409,6 +444,15 @@ export class Doclet {
     this.postProcess();
   }
 
+  #setWatchableProperty(name, newValue) {
+    const oldValue = this.watchableProps[name];
+
+    if (newValue !== oldValue) {
+      this.watchableProps[name] = newValue;
+      this.#eventBus.emit('docletChanged', { doclet: this, property: name, oldValue, newValue });
+    }
+  }
+
   // TODO: We call this method in the constructor _and_ in `jsdoc/src/handlers`. It appears that
   // if we don't call the method twice, various doclet properties can be incorrect, including name
   // and memberof.
@@ -421,7 +465,7 @@ export class Doclet {
       this.setLongname(this.name);
     }
     if (this.memberof === '') {
-      delete this.memberof;
+      this.memberof = undefined;
     }
 
     if (!this.kind && this.meta && this.meta.code) {

packages/jsdoc-doclet/test/specs/lib/doclet.js

@@ -38,6 +38,10 @@ describe('@jsdoc/doclet/lib/doclet', () => {
     expect(doclet.Doclet).toBeFunction();
   });
 
+  it('has a WATCHABLE_PROPS array', () => {
+    expect(doclet.WATCHABLE_PROPS).toBeArrayOfStrings();
+  });
+
   describe('combineDoclets', () => {
     it('overrides most properties of the secondary doclet', () => {
       const primaryDoclet = new Doclet(
@@ -347,6 +351,7 @@ describe('@jsdoc/doclet/lib/doclet', () => {
           config.opts.access = access.slice();
         }
         map.set('config', config);
+        map.set('eventBus', jsdoc.deps.get('eventBus'));
         map.set('tags', jsdoc.deps.get('tags'));
 
         return map;
@@ -385,7 +390,7 @@ describe('@jsdoc/doclet/lib/doclet', () => {
           const newDoclet = makeDoclet(['@name foo', '@function']);
 
           // Just to be sure.
-          delete newDoclet.access;
+          newDoclet.access = undefined;
 
           expect(newDoclet.isVisible()).toBeTrue();
         });
@@ -402,7 +407,7 @@ describe('@jsdoc/doclet/lib/doclet', () => {
             newDoclet = makeDoclet(tags, fakeDeps);
             // Just to be sure.
             if (!value) {
-              delete newDoclet.access;
+              newDoclet.access = undefined;
             }
 
             return newDoclet;
@@ -439,7 +444,7 @@ describe('@jsdoc/doclet/lib/doclet', () => {
           const newDoclet = makeDoclet(['@function', '@name foo'], fakeDeps);
 
           // Just to be sure.
-          delete newDoclet.access;
+          newDoclet.access = undefined;
 
           expect(newDoclet.isVisible()).toBeFalse();
         });
@@ -488,6 +493,76 @@ describe('@jsdoc/doclet/lib/doclet', () => {
           expect(setScope).toThrow();
         });
       });
+
+      describe('watchable properties', () => {
+        const eventBus = jsdoc.deps.get('eventBus');
+        let events;
+
+        function listener(e) {
+          events.push(e);
+        }
+
+        beforeEach(() => {
+          eventBus.on('docletChanged', listener);
+          events = [];
+        });
+
+        afterEach(() => {
+          eventBus.removeListener('docletChanged', listener);
+        });
+
+        it('sends events to the event bus when watchable properties change', () => {
+          const propValues = {
+            access: 'private',
+            augments: 'Foo',
+            borrowed: true,
+            ignore: true,
+            implements: 'Foo',
+            kind: 'class',
+            listens: 'event:foo',
+            longname: 'foo',
+            memberof: 'foo',
+            mixes: 'foo',
+            scope: 'static',
+            undocumented: true,
+          };
+          const keys = Object.keys(propValues);
+
+          // Make sure this test covers all watchable properties.
+          expect(keys).toEqual(doclet.WATCHABLE_PROPS);
+
+          keys.forEach((key) => {
+            const newDoclet = new Doclet('/** Huzzah, a doclet! */', null, jsdoc.deps);
+
+            events = [];
+
+            // Generates first event.
+            newDoclet[key] = propValues[key];
+            // Generates second event.
+            newDoclet[key] = undefined;
+
+            expect(events.length).toBe(2);
+
+            expect(events[0]).toBeObject();
+            expect(events[0].doclet).toBe(newDoclet);
+            expect(events[0].property).toBe(key);
+            if (key === 'kind') {
+              expect(events[0].oldValue).toBe('member');
+            } else if (key === 'longname') {
+              expect(events[0].oldValue).toBeEmptyString();
+            } else {
+              expect(events[0].oldValue).toBeUndefined();
+            }
+            expect(events[0].newValue).toBe(propValues[key]);
+
+            expect(events[1]).toBeObject();
+            expect(events[1].doclet).toBe(newDoclet);
+            expect(events[1].property).toBe(key);
+            expect(events[1].oldValue).toBe(propValues[key]);
+            expect(events[1].newValue).toBeUndefined();
+          });
+        });
+      });
     });
   });
 });

packages/jsdoc-parse/lib/parser.js

@@ -631,7 +631,7 @@ export class Parser extends EventEmitter {
           e.doclet.type = _.cloneDeep(doclet.type);
         }
 
-        delete e.doclet.undocumented;
+        e.doclet.undocumented = undefined;
         e.doclet.defaultvalue = e.doclet.meta.code.value;
 
         // add the doclet to the parent's properties

packages/jsdoc-tag/lib/definitions/core.js

@@ -44,7 +44,7 @@ export const tags = {
       if (/^(package|private|protected|public)$/i.test(value)) {
         doclet.access = value.toLowerCase();
       } else {
-        delete doclet.access;
+        doclet.access = undefined;
       }
     },
   },
@@ -263,7 +263,7 @@ export const tags = {
     mustNotHaveValue: true,
     onTagged(doclet) {
       doclet.scope = SCOPE.NAMES.GLOBAL;
-      delete doclet.memberof;
+      doclet.memberof = undefined;
     },
   },
   hideconstructor: {
@@ -349,7 +349,7 @@ export const tags = {
         doclet.forceMemberof = true;
         if (tag.value === LONGNAMES.GLOBAL) {
           doclet.addTag('global');
-          delete doclet.memberof;
+          doclet.memberof = undefined;
         }
       }
       util.setDocletMemberof(doclet, tag);

packages/jsdoc/cli.js

@@ -179,6 +179,8 @@ export default (() => {
     let cmd;
     const options = dependencies.get('options');
 
+    dependencies.registerValue('eventBus', bus);
+
     // If we already need to exit with an error, don't do any more work.
     if (props.shouldExitWithError) {
       cmd = () => Promise.resolve(0);