[6.x] [uiSettingsClient] support overriding local defaults (#17559) (#17569)

* [uiSettingsClient] support overriding local defaults

* [chrome] remove injected uiSettings value

src/ui/public/chrome/api/angular.js

@@ -24,7 +24,6 @@ export function initAngularApi(chrome, internals) {
       .value('buildNum', internals.buildNum)
       .value('buildSha', internals.buildSha)
       .value('serverName', internals.serverName)
-      .value('uiSettings', internals.uiSettings)
       .value('sessionId', Date.now())
       .value('chrome', chrome)
       .value('esUrl', (function () {

src/ui/ui_settings/public/__snapshots__/ui_settings_client.test.js.snap

@@ -20,6 +20,81 @@ You can use \`config.get(\\"throwableProperty\\", defaultValue)\`, which will ju
 \`defaultValue\` when the key is unrecognized."
 `;
 
+exports[`#overrideLocalDefault key has no user value calls subscriber with new and previous value: single subscriber call 1`] = `
+Array [
+  Array [
+    Object {
+      "key": "dateFormat",
+      "newValue": "bar",
+      "oldValue": "Browser",
+    },
+  ],
+]
+`;
+
+exports[`#overrideLocalDefault key has no user value synchonously modifies the default value returned by get(): get after override 1`] = `"bar"`;
+
+exports[`#overrideLocalDefault key has no user value synchonously modifies the default value returned by get(): get before override 1`] = `"Browser"`;
+
+exports[`#overrideLocalDefault key has no user value synchonously modifies the value returned by getAll(): getAll after override 1`] = `
+Object {
+  "dateFormat": Object {
+    "value": "bar",
+  },
+}
+`;
+
+exports[`#overrideLocalDefault key has no user value synchonously modifies the value returned by getAll(): getAll before override 1`] = `
+Object {
+  "dateFormat": Object {
+    "value": "Browser",
+  },
+}
+`;
+
+exports[`#overrideLocalDefault key with user value does not modify the return value of get: get after override 1`] = `"foo"`;
+
+exports[`#overrideLocalDefault key with user value does not modify the return value of get: get before override 1`] = `"foo"`;
+
+exports[`#overrideLocalDefault key with user value is included in the return value of getAll: getAll after override 1`] = `
+Object {
+  "dateFormat": Object {
+    "userValue": "foo",
+    "value": "bar",
+  },
+}
+`;
+
+exports[`#overrideLocalDefault key with user value is included in the return value of getAll: getAll before override 1`] = `
+Object {
+  "dateFormat": Object {
+    "userValue": "foo",
+    "value": "Browser",
+  },
+}
+`;
+
+exports[`#overrideLocalDefault key with user value returns default override when setting removed: get after override 1`] = `"bar"`;
+
+exports[`#overrideLocalDefault key with user value returns default override when setting removed: get before override 1`] = `"foo"`;
+
+exports[`#overrideLocalDefault key with user value returns default override when setting removed: getAll after override 1`] = `
+Object {
+  "dateFormat": Object {
+    "value": "bar",
+  },
+}
+`;
+
+exports[`#overrideLocalDefault key with user value returns default override when setting removed: getAll before override 1`] = `
+Object {
+  "dateFormat": Object {
+    "userValue": "foo",
+    "value": "bar",
+  },
+}
+`;
+
 exports[`#subscribe calls handler with { key, newValue, oldValue } when config changes 1`] = `
 Array [
   Array [

src/ui/ui_settings/public/ui_settings_client.js

@@ -83,6 +83,30 @@ You can use \`config.get("${key}", defaultValue)\`, which will just return
     return this.isDeclared(key) && !('value' in this._cache[key]);
   }
 
+  overrideLocalDefault(key, newDefault) {
+    // capture the previous value
+    const prevDefault = this._defaults[key]
+      ? this._defaults[key].value
+      : undefined;
+
+    // update defaults map
+    this._defaults[key] = {
+      ...this._defaults[key] || {},
+      value: newDefault
+    };
+
+    // update cached default value
+    this._cache[key] = {
+      ...this._cache[key] || {},
+      value: newDefault
+    };
+
+    // don't broadcast change if userValue was already overriding the default
+    if (this._cache[key].userValue == null) {
+      this._broadcastUpdate(key, newDefault, prevDefault);
+    }
+  }
+
   subscribe(observer) {
     this._updateObservers.add(observer);
 
@@ -139,6 +163,10 @@ You can use \`config.get("${key}", defaultValue)\`, which will just return
       }
     }
 
+    this._broadcastUpdate(key, newValue, oldValue);
+  }
+
+  _broadcastUpdate(key, newValue, oldValue) {
     this._notify.log(`config change: ${key}: ${oldValue} -> ${newValue}`);
 
     for (const observer of this._updateObservers) {

src/ui/ui_settings/public/ui_settings_client.test.js

@@ -201,3 +201,77 @@ describe('#subscribe', () => {
     expect(handler).not.toHaveBeenCalled();
   });
 });
+
+describe('#overrideLocalDefault', () => {
+  describe('key has no user value', () => {
+    it('synchonously modifies the default value returned by get()', () => {
+      const { config } = setup();
+
+      expect(config.get('dateFormat')).toMatchSnapshot('get before override');
+      config.overrideLocalDefault('dateFormat', 'bar');
+      expect(config.get('dateFormat')).toMatchSnapshot('get after override');
+    });
+
+    it('synchonously modifies the value returned by getAll()', () => {
+      const { config } = setup();
+
+      expect(config.getAll()).toMatchSnapshot('getAll before override');
+      config.overrideLocalDefault('dateFormat', 'bar');
+      expect(config.getAll()).toMatchSnapshot('getAll after override');
+    });
+
+    it('calls subscriber with new and previous value', () => {
+      const handler = jest.fn();
+      const { config } = setup();
+
+      config.subscribe(handler);
+      config.overrideLocalDefault('dateFormat', 'bar');
+      expect(handler.mock.calls).toMatchSnapshot('single subscriber call');
+    });
+  });
+
+  describe('key with user value', () => {
+    it('does not modify the return value of get', () => {
+      const { config } = setup();
+
+      config.set('dateFormat', 'foo');
+      expect(config.get('dateFormat')).toMatchSnapshot('get before override');
+      config.overrideLocalDefault('dateFormat', 'bar');
+      expect(config.get('dateFormat')).toMatchSnapshot('get after override');
+    });
+
+    it('is included in the return value of getAll', () => {
+      const { config } = setup();
+
+      config.set('dateFormat', 'foo');
+      expect(config.getAll()).toMatchSnapshot('getAll before override');
+      config.overrideLocalDefault('dateFormat', 'bar');
+      expect(config.getAll()).toMatchSnapshot('getAll after override');
+    });
+
+    it('does not call subscriber', () => {
+      const handler = jest.fn();
+      const { config } = setup();
+
+      config.set('dateFormat', 'foo');
+      config.subscribe(handler);
+      config.overrideLocalDefault('dateFormat', 'bar');
+      expect(handler).not.toHaveBeenCalled();
+    });
+
+    it('returns default override when setting removed', () => {
+      const { config } = setup();
+
+      config.set('dateFormat', 'foo');
+      config.overrideLocalDefault('dateFormat', 'bar');
+
+      expect(config.get('dateFormat')).toMatchSnapshot('get before override');
+      expect(config.getAll()).toMatchSnapshot('getAll before override');
+
+      config.remove('dateFormat');
+
+      expect(config.get('dateFormat')).toMatchSnapshot('get after override');
+      expect(config.getAll()).toMatchSnapshot('getAll after override');
+    });
+  });
+});