feat(a2ui): normalize icon names to Material Symbols ligatures (camelCase → snake_case) (#725)

A2UI catalogs commonly emit camelCase icon identifiers (accountCircle,
shoppingCart, moreVert) while Material Symbols ligatures are snake_case. The
Icon component now converts the name before rendering so the existing A2UI
icon vocabulary renders as real glyphs (not raw text). Single-word /
already-snake_case names + emoji pass through unchanged; the original name is
kept as the aria-label. Verified live in examples/chat (A2UI mode): an Account
card renders account_circle / shopping_cart / settings / notifications / star
glyphs.

Author: blove

libs/chat/src/lib/a2ui/catalog/icon.component.spec.ts

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MIT
 import { describe, it, expect } from 'vitest';
-import { A2uiIconComponent } from './icon.component';
+import { A2uiIconComponent, toMaterialSymbolName } from './icon.component';
 
 describe('A2uiIconComponent', () => {
   // Display-only component: renders name() input as a <span>.
@@ -11,3 +11,24 @@ describe('A2uiIconComponent', () => {
     expect(A2uiIconComponent).toBeDefined();
   });
 });
+
+describe('toMaterialSymbolName', () => {
+  it('converts camelCase identifiers to snake_case ligatures', () => {
+    expect(toMaterialSymbolName('accountCircle')).toBe('account_circle');
+    expect(toMaterialSymbolName('shoppingCart')).toBe('shopping_cart');
+    expect(toMaterialSymbolName('moreVert')).toBe('more_vert');
+    expect(toMaterialSymbolName('visibilityOff')).toBe('visibility_off');
+    expect(toMaterialSymbolName('arrowForward')).toBe('arrow_forward');
+  });
+
+  it('passes single-word and already-snake_case names through unchanged', () => {
+    expect(toMaterialSymbolName('check')).toBe('check');
+    expect(toMaterialSymbolName('star')).toBe('star');
+    expect(toMaterialSymbolName('trending_up')).toBe('trending_up');
+  });
+
+  it('leaves non-identifier glyphs (emoji) untouched', () => {
+    expect(toMaterialSymbolName('✓')).toBe('✓');
+    expect(toMaterialSymbolName('⚠️')).toBe('⚠️');
+  });
+});

libs/chat/src/lib/a2ui/catalog/icon.component.ts

@@ -2,6 +2,20 @@
 import { Component, computed, input } from '@angular/core';
 import type { Spec } from '@json-render/core';
 
+/**
+ * Convert an icon identifier to its Material Symbols ligature form.
+ *
+ * Material Symbols ligatures are snake_case (`account_circle`, `trending_up`),
+ * but A2UI catalogs commonly emit camelCase identifiers (`accountCircle`,
+ * `shoppingCart`). Splitting on lower→upper boundaries and lowercasing maps
+ * camelCase → the matching ligature. Already-snake_case names, single words,
+ * and non-identifier glyphs (emoji) have no boundaries to split and pass
+ * through unchanged. Unknown names still fall back to the browser default.
+ */
+export function toMaterialSymbolName(name: string): string {
+  return name.replace(/([a-z0-9])([A-Z])/g, '$1_$2').toLowerCase();
+}
+
 @Component({
   selector: 'a2ui-icon',
   standalone: true,
@@ -12,7 +26,7 @@ import type { Spec } from '@json-render/core';
         [style.font-size]="size() ? size() + 'px' : '1.125rem'"
         [attr.aria-label]="name"
         role="img"
-      >{{ name }}</span>
+      >{{ glyphName() }}</span>
     }
   `,
   styles: [`
@@ -56,4 +70,7 @@ export class A2uiIconComponent {
   readonly spec = input<Spec | undefined>(undefined);
 
   protected readonly effectiveName = computed(() => this.name() ?? this.icon());
+
+  /** The effective name as a Material Symbols ligature (camelCase → snake_case). */
+  protected readonly glyphName = computed(() => toMaterialSymbolName(this.effectiveName()));
 }