fix(settings): add logic to detect changes in deeply-nested settings #2654

Author: JadenSimon

src/shared/settings.ts

@@ -248,10 +248,14 @@ function createSettingsClass<T extends TypeDescriptor>(section: string, descript
             //
             // So if `aws.foo.bar` changed, this would fire with data `{ key: 'bar' }`
             const props = keys(descriptor)
+            const store = toRecord(props, p => this.get(p))
             const emitter = new vscode.EventEmitter<{ readonly key: keyof T }>()
             const listener = this.settings.onDidChangeSection(section, event => {
-                for (const key of props.filter(p => event.affectsConfiguration(p))) {
+                const isDifferent = (p: keyof T & string) => event.affectsConfiguration(p) || store[p] !== this.get(p)
+
+                for (const key of props.filter(isDifferent)) {
                     this.log(`key "${key}" changed`)
+                    store[key] = this.get(key)
                     emitter.fire({ key })
                 }
             })

src/test/shared/settingsConfiguration.test.ts

@@ -328,4 +328,25 @@ describe('Experiments', function () {
         await sut.update('jsonResourceModification', true)
         assert.strictEqual(await sut.isExperimentEnabled('jsonResourceModification'), true)
     })
+
+    it('fires events from nested settings', async function () {
+        const info = vscode.workspace.getConfiguration().inspect('aws.experiments.jsonResourceModification')
+        if (info?.globalValue) {
+            this.skip()
+        }
+
+        const experiments = new Experiments(new Settings(vscode.ConfigurationTarget.Workspace))
+
+        try {
+            const key = new Promise<string>((resolve, reject) => {
+                experiments.onDidChange(event => resolve(event.key))
+                setTimeout(() => reject(new Error('Timed out waiting for settings event')), 5000)
+            })
+
+            await experiments.update('jsonResourceModification', true)
+            assert.strictEqual(await key, 'jsonResourceModification')
+        } finally {
+            await experiments.reset()
+        }
+    })
 })