fix(target-angular): dedupe @ContentChild slot fields per distinct slot name

A template that references the same named slot in multiple locations (e.g.
DataTable's `colHeader`, Slider's `bubble`) drove `emitScript` to emit one
`@ContentChild` field, one ctx `interface`, and one `ngTemplateContextGuard`
union member PER reference. The duplicate class members produced an esbuild
"Duplicate member" parse error and duplicate interface identifiers (TS2300),
which crashed the Angular build — and with it the Visual Regression Matrix dev
server (webserver-start timeout) on every push.

The 47-03 slot-decl dedup (Lit/Solid/Svelte/React) never covered Angular's
inline `@ContentChild` emission path. Add the same distinct-slot-name dedup in
`emitScript` (fields + ctx interfaces) and in `buildNgTemplateContextGuard`
(union members), plus a regression test for a slot referenced twice.

Regenerated the DataTable + Slider Angular leaves; verified end-to-end via the
CLI that Slider emits a single `@ContentChild('bubble')`. Core + all six target
suites + dist-parity green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014ArTPHLhYMwrjvvoF9VXDe

Author: serpentblade

packages/targets/angular/src/__tests__/emitScript.test.ts

@@ -176,6 +176,56 @@ describe('emitScript — TodoList slot context interfaces', () => {
   });
 });
 
+describe('emitScript — repeated named-slot dedup (regression)', () => {
+  // A template may reference the same named slot in multiple locations (e.g.
+  // DataTable's `colHeader`, Slider's `bubble`). Each distinct name backs
+  // exactly one @ContentChild field + one ctx interface; emitting one per
+  // reference produced "Duplicate member" (esbuild) and TS2300 (duplicate
+  // identifier), crashing the Angular build. Regression guard for that fix.
+  function loadInlineIR(src: string): IRComponent {
+    const result = parse(src, { filename: 'RepeatedSlot.rozie' });
+    if (!result.ast) throw new Error('parse() returned null AST');
+    const lowered = lowerToIR(result.ast, {
+      modifierRegistry: createDefaultRegistry(),
+    });
+    if (!lowered.ir) throw new Error('lowerToIR() returned null IR');
+    return lowered.ir;
+  }
+
+  const SRC = `<rozie name="RepeatedSlot">
+<template>
+  <div>
+    <slot name="bubble" :value="1" />
+    <slot name="bubble" :value="2" />
+  </div>
+</template>
+</rozie>`;
+
+  it('emits exactly one @ContentChild for a slot referenced twice', () => {
+    const ir = loadInlineIR(SRC);
+    const { classBody } = emitScript(ir);
+    const occurrences = classBody.match(/@ContentChild\('bubble'/g) ?? [];
+    expect(occurrences).toHaveLength(1);
+  });
+
+  it('emits exactly one ctx interface for a repeated slot', () => {
+    const ir = loadInlineIR(SRC);
+    const { interfaceDecls } = emitScript(ir);
+    const joined = interfaceDecls.join('\n');
+    const occurrences = joined.match(/interface BubbleCtx\b/g) ?? [];
+    expect(occurrences).toHaveLength(1);
+  });
+
+  it('ngTemplateContextGuard union has no repeated members', () => {
+    const ir = loadInlineIR(SRC);
+    const { classBody } = emitScript(ir);
+    const occurrences = classBody.match(/\bBubbleCtx\b/g) ?? [];
+    // BubbleCtx appears once in the @ContentChild field type and once in the
+    // guard union — never twice in either site.
+    expect(occurrences).toHaveLength(2);
+  });
+});
+
 describe('emitScript — per-block snapshot fixtures', () => {
   it('Counter.script.snap', async () => {
     const ir = loadIR('Counter');

packages/targets/angular/src/emit/emitScript.ts

@@ -869,7 +869,17 @@ export function emitScript(
     interfaceDecls.push(genCode(typeDecl));
   }
   const slotFieldDecls: string[] = [];
+  // Dedupe by DISTINCT slot name — a template may reference the same named
+  // slot in multiple locations (e.g. DataTable's `colHeader`, Slider's
+  // `bubble`), but each distinct name backs exactly one `@ContentChild` field
+  // and one ctx interface. Without this, repeated references emit duplicate
+  // class members ("Duplicate member" esbuild error) and duplicate interface
+  // identifiers (TS2300), breaking the Angular build. Mirrors the per-target
+  // `seenSlotNames` dedup in Lit/Solid/Svelte/React emitSlotDecl.ts (47-03).
+  const seenSlotNames = new Set<string>();
   for (const slot of ir.slots) {
+    if (seenSlotNames.has(slot.name)) continue;
+    seenSlotNames.add(slot.name);
     const ctx = buildSlotCtx(slot);
     interfaceDecls.push(ctx.interfaceDecl);
     slotFieldDecls.push(ctx.fieldDecl);

packages/targets/angular/src/emit/refineSlotTypes.ts

@@ -99,7 +99,17 @@ export function buildNgTemplateContextGuard(
   slots: SlotDecl[],
 ): string | null {
   if (slots.length === 0) return null;
-  const ctxNames = slots.map((s) => slotCtxName(s.name));
+  // Dedupe by distinct slot name — a slot referenced in multiple template
+  // locations appears multiple times in `slots`, but each distinct name has a
+  // single ctx type. Without this the union repeats members (`FooCtx | FooCtx`).
+  const seenCtxNames = new Set<string>();
+  const ctxNames: string[] = [];
+  for (const s of slots) {
+    const ctxName = slotCtxName(s.name);
+    if (seenCtxNames.has(ctxName)) continue;
+    seenCtxNames.add(ctxName);
+    ctxNames.push(ctxName);
+  }
   const unionType = ctxNames.join(' | ');
   return [
     `static ngTemplateContextGuard(`,

packages/ui/data-table/packages/angular/src/DataTable.ts

@@ -58,13 +58,6 @@ interface ColHeaderCtx {
   label: any;
 }
 
-interface ColHeaderCtx {
-  $implicit: { columnId: any; column: any; label: any };
-  columnId: any;
-  column: any;
-  label: any;
-}
-
 interface FilterCtx {
   $implicit: { columnId: any; uniqueValues: any; minMax: any };
   columnId: any;
@@ -97,67 +90,6 @@ interface CellCtx {
   value: any;
 }
 
-interface SelectAllCtx {
-  $implicit: { checked: any; indeterminate: any; toggle: any };
-  checked: any;
-  indeterminate: any;
-  toggle: any;
-}
-
-interface ColHeaderCtx {
-  $implicit: { columnId: any; column: any; label: any };
-  columnId: any;
-  column: any;
-  label: any;
-}
-
-interface ColHeaderCtx {
-  $implicit: { columnId: any; column: any; label: any };
-  columnId: any;
-  column: any;
-  label: any;
-}
-
-interface FilterCtx {
-  $implicit: { columnId: any; uniqueValues: any; minMax: any };
-  columnId: any;
-  uniqueValues: any;
-  minMax: any;
-}
-
-interface SelectCellCtx {
-  $implicit: { row: any; checked: any; toggle: any };
-  row: any;
-  checked: any;
-  toggle: any;
-}
-
-interface CellCtx {
-  $implicit: { columnId: any; column: any; row: any; value: any };
-  columnId: any;
-  column: any;
-  row: any;
-  value: any;
-}
-
-interface EditorCtx {
-  $implicit: { columnId: any; column: any; row: any; value: any; commit: any; cancel: any };
-  columnId: any;
-  column: any;
-  row: any;
-  value: any;
-  commit: any;
-  cancel: any;
-}
-
-interface CellCtx {
-  $implicit: { columnId: any; column: any; row: any; value: any };
-  columnId: any;
-  column: any;
-  row: any;
-  value: any;
-}
-
 interface DetailCtx {
   $implicit: { row: any };
   row: any;
@@ -894,19 +826,10 @@ export class DataTable {
   @ContentChild('groupBar', { read: TemplateRef }) groupBarTpl?: TemplateRef<GroupBarCtx>;
   @ContentChild('selectAll', { read: TemplateRef }) selectAllTpl?: TemplateRef<SelectAllCtx>;
   @ContentChild('colHeader', { read: TemplateRef }) colHeaderTpl?: TemplateRef<ColHeaderCtx>;
-  @ContentChild('colHeader', { read: TemplateRef }) colHeaderTpl?: TemplateRef<ColHeaderCtx>;
   @ContentChild('filter', { read: TemplateRef }) filterTpl?: TemplateRef<FilterCtx>;
   @ContentChild('selectCell', { read: TemplateRef }) selectCellTpl?: TemplateRef<SelectCellCtx>;
   @ContentChild('editor', { read: TemplateRef }) editorTpl?: TemplateRef<EditorCtx>;
   @ContentChild('cell', { read: TemplateRef }) cellTpl?: TemplateRef<CellCtx>;
-  @ContentChild('selectAll', { read: TemplateRef }) selectAllTpl?: TemplateRef<SelectAllCtx>;
-  @ContentChild('colHeader', { read: TemplateRef }) colHeaderTpl?: TemplateRef<ColHeaderCtx>;
-  @ContentChild('colHeader', { read: TemplateRef }) colHeaderTpl?: TemplateRef<ColHeaderCtx>;
-  @ContentChild('filter', { read: TemplateRef }) filterTpl?: TemplateRef<FilterCtx>;
-  @ContentChild('selectCell', { read: TemplateRef }) selectCellTpl?: TemplateRef<SelectCellCtx>;
-  @ContentChild('cell', { read: TemplateRef }) cellTpl?: TemplateRef<CellCtx>;
-  @ContentChild('editor', { read: TemplateRef }) editorTpl?: TemplateRef<EditorCtx>;
-  @ContentChild('cell', { read: TemplateRef }) cellTpl?: TemplateRef<CellCtx>;
   @ContentChild('detail', { read: TemplateRef }) detailTpl?: TemplateRef<DetailCtx>;
   templates = input<Record<string, TemplateRef<unknown>> | undefined>(undefined);
   private __rozieWatchInitial_0 = true;
@@ -3363,7 +3286,7 @@ export class DataTable {
   static ngTemplateContextGuard(
     _dir: DataTable,
     _ctx: unknown,
-  ): _ctx is DefaultCtx | GroupBarCtx | SelectAllCtx | ColHeaderCtx | ColHeaderCtx | FilterCtx | SelectCellCtx | EditorCtx | CellCtx | SelectAllCtx | ColHeaderCtx | ColHeaderCtx | FilterCtx | SelectCellCtx | CellCtx | EditorCtx | CellCtx | DetailCtx {
+  ): _ctx is DefaultCtx | GroupBarCtx | SelectAllCtx | ColHeaderCtx | FilterCtx | SelectCellCtx | EditorCtx | CellCtx | DetailCtx {
     return true;
   }
 

packages/ui/slider/packages/angular/src/Slider.ts

@@ -14,16 +14,6 @@ interface BubbleCtx {
   value: any;
 }
 
-interface BubbleCtx {
-  $implicit: { value: any };
-  value: any;
-}
-
-interface BubbleCtx {
-  $implicit: { value: any };
-  value: any;
-}
-
 function __rozieDisplay(v: unknown): string {
   if (v == null) return '';
   if (typeof v === 'string') return v;
@@ -293,8 +283,6 @@ export class Slider {
   change = output<unknown>();
   @ContentChild('mark', { read: TemplateRef }) markTpl?: TemplateRef<MarkCtx>;
   @ContentChild('bubble', { read: TemplateRef }) bubbleTpl?: TemplateRef<BubbleCtx>;
-  @ContentChild('bubble', { read: TemplateRef }) bubbleTpl?: TemplateRef<BubbleCtx>;
-  @ContentChild('bubble', { read: TemplateRef }) bubbleTpl?: TemplateRef<BubbleCtx>;
   templates = input<Record<string, TemplateRef<unknown>> | undefined>(undefined);
 
   fillStyle = computed(() => {
@@ -461,7 +449,7 @@ export class Slider {
   static ngTemplateContextGuard(
     _dir: Slider,
     _ctx: unknown,
-  ): _ctx is MarkCtx | BubbleCtx | BubbleCtx | BubbleCtx {
+  ): _ctx is MarkCtx | BubbleCtx {
     return true;
   }