test(desktop): cover the composer chip plaintext-demotion bug class

Backspace path-ascend keeping the leading command pill, folder picks
alongside a command pill, commits spanning Chromium-split text nodes,
slash-pill hydration boundaries (committed vs half-typed vs arg-taking),
and replaceBeforeCaret refusing across chip boundaries.

apps/desktop/src/app/chat/composer/hooks/use-composer-trigger.test.ts

@@ -223,3 +223,72 @@ describe('useComposerTrigger — free-text slash arguments', () => {
     expect(editor.querySelector('[data-slash-kind]')?.getAttribute('data-ref-text')).toBe('/personality creative')
   })
 })
+
+describe('useComposerTrigger — chip survival (the plaintext-demotion bug class)', () => {
+  it('keeps a leading command pill through a Backspace path-ascend', () => {
+    // The reported repro: `/work @folder…` then Backspace — both chips went
+    // plaintext because ascend re-rendered the whole editor from text.
+    const editor = mountEditor('/work @Desktop/')
+    const { hook } = mountTrigger(editor, [])
+
+    expect(editor.querySelector('[data-slash-kind]')).not.toBeNull()
+
+    act(() => hook.result.current.refreshTrigger())
+    expect(hook.result.current.trigger).toMatchObject({ kind: '@', query: 'Desktop/' })
+
+    let ran = false
+    act(() => {
+      ran = hook.result.current.ascendTriggerPath()
+    })
+
+    expect(ran).toBe(true)
+    expect(composerPlainText(editor)).toBe('/work @')
+    expect(editor.querySelector('[data-slash-kind]')).not.toBeNull()
+  })
+
+  it('keeps a leading command pill when a folder pick commits its ref chip', () => {
+    const editor = mountEditor('/work @Desk')
+
+    const folder: Unstable_TriggerItem = {
+      id: 'folder:Desktop',
+      type: 'folder',
+      label: 'Desktop',
+      metadata: { rawText: '@folder:Desktop', insertId: 'Desktop' }
+    }
+
+    const { hook } = mountTrigger(editor, [folder])
+
+    act(() => hook.result.current.refreshTrigger())
+    act(() => hook.result.current.replaceTriggerWithChip(folder))
+
+    expect(composerPlainText(editor)).toBe('/work @folder:`Desktop` ')
+    expect(editor.querySelector('[data-slash-kind]')).not.toBeNull()
+    expect(editor.querySelector('[data-ref-kind="folder"]')).not.toBeNull()
+  })
+
+  it('commits in place when Chromium has split the token across text nodes', () => {
+    // Chromium fragments text nodes around contenteditable=false chips; the
+    // commit path must span the fragments instead of bailing to a full
+    // re-render.
+    const editor = document.createElement('div')
+    editor.dataset.slot = RICH_INPUT_SLOT
+    editor.contentEditable = 'true'
+    document.body.append(editor)
+    editor.append(document.createTextNode('please run /c'), document.createTextNode('le'))
+
+    const caret = document.createRange()
+    caret.setStart(editor.lastChild!, 2)
+    caret.collapse(true)
+    const selection = window.getSelection()!
+    selection.removeAllRanges()
+    selection.addRange(caret)
+
+    const { hook } = mountTrigger(editor, [item('/clean')])
+
+    act(() => hook.result.current.refreshTrigger())
+    act(() => hook.result.current.replaceTriggerWithChip(item('/clean')))
+
+    expect(composerPlainText(editor)).toBe('please run /clean ')
+    expect(editor.querySelector('[data-slash-kind]')).not.toBeNull()
+  })
+})

apps/desktop/src/app/chat/composer/rich-editor.test.ts

@@ -35,6 +35,89 @@ describe('renderComposerContents', () => {
     expect(editor.textContent).toContain('<b>raw</b>')
     expect(composerPlainText(editor)).toBe('@file:`<img src=x onerror=alert(1)>` <b>raw</b>')
   })
+
+  it('hydrates a committed leading slash command back to its pill', () => {
+    // Text-hydration parity with @ refs: a re-render from serialized text
+    // (draft restore, undo, the trigger commit fallback) must not demote a
+    // committed no-arg command chip to plain text.
+    const editor = document.createElement('div')
+    editor.dataset.slot = RICH_INPUT_SLOT
+
+    renderComposerContents(editor, '/some-skill @folder:`Desktop` ')
+
+    const pill = editor.querySelector('[data-slash-kind]')
+
+    expect(pill?.getAttribute('data-ref-text')).toBe('/some-skill')
+    expect(editor.querySelector('[data-ref-kind="folder"]')).not.toBeNull()
+    expect(composerPlainText(editor)).toBe('/some-skill @folder:`Desktop` ')
+  })
+
+  it('keeps a still-typed leading slash token as editable text', () => {
+    const editor = document.createElement('div')
+    editor.dataset.slot = RICH_INPUT_SLOT
+
+    // No trailing whitespace — not committed yet.
+    renderComposerContents(editor, '/some-skil')
+
+    expect(editor.querySelector('[data-slash-kind]')).toBeNull()
+    expect(composerPlainText(editor)).toBe('/some-skil')
+  })
+
+  it('keeps an arg-taking command as text — its tail may be uncommitted prose', () => {
+    const editor = document.createElement('div')
+    editor.dataset.slot = RICH_INPUT_SLOT
+
+    renderComposerContents(editor, '/goal ship the redesign')
+
+    expect(editor.querySelector('[data-slash-kind]')).toBeNull()
+    expect(composerPlainText(editor)).toBe('/goal ship the redesign')
+  })
+})
+
+describe('replaceBeforeCaret across split text nodes', () => {
+  it('replaces a token that Chromium fragmented into multiple text nodes', () => {
+    const editor = document.createElement('div')
+    editor.dataset.slot = RICH_INPUT_SLOT
+    editor.contentEditable = 'true'
+    document.body.append(editor)
+    editor.append(document.createTextNode('see @Desk'), document.createTextNode('top/'))
+
+    const caret = document.createRange()
+    caret.setStart(editor.lastChild!, 4)
+    caret.collapse(true)
+    const selection = window.getSelection()!
+    selection.removeAllRanges()
+    selection.addRange(caret)
+
+    const fragment = document.createDocumentFragment()
+    fragment.append(refChipElement('folder', '`Desktop`'), document.createTextNode(' '))
+
+    // Token `@Desktop/` (9 chars) spans both text nodes.
+    expect(replaceBeforeCaret(editor, 9, fragment)).toBe(true)
+    expect(composerPlainText(editor)).toBe('see @folder:`Desktop` ')
+
+    editor.remove()
+  })
+
+  it('refuses when a chip interrupts the span — the token is not contiguous text', () => {
+    const editor = document.createElement('div')
+    editor.dataset.slot = RICH_INPUT_SLOT
+    editor.contentEditable = 'true'
+    document.body.append(editor)
+    editor.append(document.createTextNode('a'), refChipElement('file', '`x`'), document.createTextNode('bc'))
+
+    const caret = document.createRange()
+    caret.setStart(editor.lastChild!, 2)
+    caret.collapse(true)
+    const selection = window.getSelection()!
+    selection.removeAllRanges()
+    selection.addRange(caret)
+
+    expect(replaceBeforeCaret(editor, 5, document.createDocumentFragment())).toBe(false)
+    expect(composerPlainText(editor)).toBe('a@file:`x`bc')
+
+    editor.remove()
+  })
 })
 
 describe('normalizeComposerEditorDom', () => {

apps/desktop/src/app/chat/composer/text-utils.test.ts

@@ -65,6 +65,18 @@ describe('detectTrigger', () => {
     })
   })
 
+  it('treats a chip edge as a token boundary, like whitespace', () => {
+    // U+FFFC is textBeforeCaret's placeholder for a committed pill. Upstream
+    // assistant-ui's Lexical DirectivePlugin gets the same semantics from node
+    // boundaries: typing a trigger right after a chip (no space) still opens
+    // the popover, and a chip inside a token ends it.
+    expect(detectTrigger('\uFFFC@Desk')).toEqual({ kind: '@', query: 'Desk', tokenLength: 5 })
+    // Not position 0, so it's an inline reference — not a command invocation.
+    expect(detectTrigger('\uFFFC/cle')).toEqual({ inline: true, kind: '/', query: 'cle', tokenLength: 4 })
+    // The placeholder itself never leaks into a query.
+    expect(detectTrigger('@a\uFFFCb')).toBeNull()
+  })
+
   it('keeps the at-mention live for a typed ref kind with a path', () => {
     expect(detectTrigger('@file:src/main.tsx')).toEqual({
       kind: '@',