refactor(multiple): simplify LabelControl and include in public api

Author: adolgachev

goldens/aria/private/index.api.md

@@ -429,6 +429,22 @@ export interface HasElement {
     element: HTMLElement;
 }
 
+// @public
+export class LabelControl {
+    constructor(inputs: LabelControlInputs);
+    // (undocumented)
+    readonly inputs: LabelControlInputs;
+    readonly label: SignalLike<string | undefined>;
+    readonly labelledBy: SignalLike<string | undefined>;
+}
+
+// @public
+export interface LabelControlInputs {
+    defaultLabelledBy: SignalLike<string | undefined>;
+    label: SignalLike<string | undefined>;
+    labelledBy: SignalLike<string[] | undefined>;
+}
+
 // @public (undocumented)
 export function linkedSignal<T>(sourceFn: () => T): WritableSignalLike<T>;
 

src/aria/private/BUILD.bazel

@@ -18,6 +18,7 @@ ts_project(
     deps = [
         "//:node_modules/@angular/core",
         "//src/aria/private/accordion",
+        "//src/aria/private/behaviors/label",
         "//src/aria/private/behaviors/signal-like",
         "//src/aria/private/combobox",
         "//src/aria/private/deferred-content",

src/aria/private/behaviors/label/label.spec.ts

@@ -7,21 +7,19 @@
  */
 
 import {signal, WritableSignalLike} from '../signal-like/signal-like';
-import {LabelControl, LabelControlInputs, LabelControlOptionalInputs} from './label';
+import {LabelControl, LabelControlInputs} from './label';
 
 // This is a helper type for the initial values passed to the setup function.
 type TestInputs = Partial<{
   label: string | undefined;
-  defaultLabelledBy: string[];
+  defaultLabelledBy: string;
   labelledBy: string[];
 }>;
 
-type TestLabelControlInputs = LabelControlInputs & Required<LabelControlOptionalInputs>;
-
 // This is a helper type to make all properties of LabelControlInputs writable signals.
 type WritableLabelControlInputs = {
-  [K in keyof TestLabelControlInputs]: WritableSignalLike<
-    TestLabelControlInputs[K] extends {(): infer T} ? T : never
+  [K in keyof LabelControlInputs]: WritableSignalLike<
+    LabelControlInputs[K] extends {(): infer T} ? T : never
   >;
 };
 
@@ -30,7 +28,7 @@ function getLabelControl(initialValues: TestInputs = {}): {
   inputs: WritableLabelControlInputs;
 } {
   const inputs: WritableLabelControlInputs = {
-    defaultLabelledBy: signal(initialValues.defaultLabelledBy ?? []),
+    defaultLabelledBy: signal(initialValues.defaultLabelledBy),
     label: signal(initialValues.label),
     labelledBy: signal(initialValues.labelledBy ?? []),
   };
@@ -47,6 +45,11 @@ describe('LabelControl', () => {
       expect(control.label()).toBe('My Label');
     });
 
+    it('should return the user-provided label even ifdefaultLabelledBy is provided ', () => {
+      const {control} = getLabelControl({defaultLabelledBy: 'default-id', label: 'My Label'});
+      expect(control.label()).toBe('My Label');
+    });
+
     it('should return undefined if no label is provided', () => {
       const {control} = getLabelControl();
       expect(control.label()).toBeUndefined();
@@ -62,27 +65,27 @@ describe('LabelControl', () => {
   });
 
   describe('#labelledBy', () => {
-    it('should return user-provided labelledBy even if a label is provided', () => {
+    it('should return user-provided labelledBy ids even if a label is provided', () => {
       const {control} = getLabelControl({
         label: 'My Label',
-        defaultLabelledBy: ['default-id'],
-        labelledBy: ['user-id'],
+        defaultLabelledBy: 'default-id',
+        labelledBy: ['user-id', 'user-id-2'],
       });
-      expect(control.labelledBy()).toEqual(['user-id']);
+      expect(control.labelledBy()).toEqual('user-id user-id-2');
     });
 
     it('should return defaultLabelledBy if no user-provided labelledBy exists', () => {
-      const {control} = getLabelControl({defaultLabelledBy: ['default-id']});
-      expect(control.labelledBy()).toEqual(['default-id']);
+      const {control} = getLabelControl({defaultLabelledBy: 'default-id'});
+      expect(control.labelledBy()).toEqual('default-id');
     });
 
     it('should update when label changes from undefined to a string', () => {
       const {control, inputs} = getLabelControl({
-        defaultLabelledBy: ['default-id'],
+        defaultLabelledBy: 'default-id',
       });
-      expect(control.labelledBy()).toEqual(['default-id']);
+      expect(control.labelledBy()).toEqual('default-id');
       inputs.label.set('A wild label appears');
-      expect(control.labelledBy()).toEqual([]);
+      expect(control.labelledBy()).toEqual(undefined);
     });
   });
 });

src/aria/private/behaviors/label/label.ts

@@ -7,44 +7,42 @@
  */
 import {computed, SignalLike} from '../signal-like/signal-like';
 
-/** Represents the required inputs for the label control. */
+/** The required inputs for the label control. */
 export interface LabelControlInputs {
-  /** The default `aria-labelledby` ids. */
-  defaultLabelledBy: SignalLike<string[]>;
-}
+  /** The default `aria-labelledby` id to use if no other inputs specified. */
+  defaultLabelledBy: SignalLike<string | undefined>;
 
-/** Represents the optional inputs for the label control. */
-export interface LabelControlOptionalInputs {
-  /** The `aria-label`. */
-  label?: SignalLike<string | undefined>;
+  /** The `aria-label` to use instead of the default id. */
+  label: SignalLike<string | undefined>;
 
-  /** The user-provided `aria-labelledby` ids. */
-  labelledBy?: SignalLike<string[]>;
+  /** The `aria-labelledby` id(s) to use instead of the default id (or label). */
+  labelledBy: SignalLike<string[] | undefined>;
 }
 
-/** Controls label and description of an element. */
+/** Controls label for an element. */
 export class LabelControl {
-  /** The `aria-label`. */
-  readonly label = computed(() => this.inputs.label?.());
+  /** Use this value to set the `aria-label` attribute on the element. */
+  readonly label = computed(() => this.inputs.label());
 
-  /** The `aria-labelledby` ids. */
+  /** Use this value to set the `aria-labelledby` attribute on the element. */
   readonly labelledBy = computed(() => {
-    const label = this.label();
-    const labelledBy = this.inputs.labelledBy?.();
     const defaultLabelledBy = this.inputs.defaultLabelledBy();
+    const label = this.label();
+    const labelledBy = this.inputs.labelledBy();
 
+    // Always use any specified labelledby ids.
     if (labelledBy && labelledBy.length > 0) {
-      return labelledBy;
+      return labelledBy.join(' ');
     }
 
-    // If an aria-label is provided by developers, do not set aria-labelledby with the
-    // defaultLabelledBy value because if both attributes are set, aria-labelledby will be used.
-    if (label) {
-      return [];
+    // If an aria-label is provided, do not set aria-labelledby with the defaultLabelledBy value
+    // because if both attributes are set, aria-labelledby will be used.
+    if (!label && defaultLabelledBy) {
+      return defaultLabelledBy;
     }
 
-    return defaultLabelledBy;
+    return undefined;
   });
 
-  constructor(readonly inputs: LabelControlInputs & LabelControlOptionalInputs) {}
+  constructor(readonly inputs: LabelControlInputs) {}
 }

src/aria/private/public-api.ts

@@ -11,6 +11,7 @@ export * from './listbox/listbox';
 export * from './listbox/option';
 export * from './listbox/combobox-listbox';
 export * from './menu/menu';
+export * from './behaviors/label/label';
 export * from './behaviors/signal-like/signal-like';
 export * from './tabs/tabs';
 export * from './toolbar/toolbar';

src/aria/private/tabs/BUILD.bazel

@@ -11,7 +11,6 @@ ts_project(
         "//:node_modules/@angular/core",
         "//src/aria/private/behaviors/event-manager",
         "//src/aria/private/behaviors/expansion",
-        "//src/aria/private/behaviors/label",
         "//src/aria/private/behaviors/list-focus",
         "//src/aria/private/behaviors/list-navigation",
         "//src/aria/private/behaviors/signal-like",