test(composer): cover the forced source reset behaviourally, not by source text

The boundaries suite pinned the project switch by matching the literal
`handleRepoChange(nextRepoId, ...)` call, which the setup-choice refactor
renamed. The invariant it protected — returning from a folder target to a repo
with the same id must force the repo-scoped reset past handleRepoChange's
same-id early return — now runs against the real handleRepoChange, so a rename
cannot break it and a dropped flag cannot pass it.

src/renderer/src/hooks/composer-state/project-target-actions.test.ts

@@ -5,6 +5,7 @@ import type { ExecutionHostId } from '../../../../shared/execution-host'
 import type { Project, ProjectHostSetup } from '../../../../shared/project-types'
 import type { Repo } from '../../../../shared/repo-types'
 import { useProjectTargetActions } from './project-target-actions'
+import { useTargetChangeActions } from './target-change-actions'
 
 const PROJECT_ID = 'github:stablyai/orca'
 
@@ -114,3 +115,98 @@ describe('composer project switch with several ready setups (STA-6080)', () => {
     expect(spies.setRepoId).not.toHaveBeenCalled()
   })
 })
+
+/**
+ * The folder branch of the composer leaves `repoId` on the group's source repo, so switching back to
+ * a project whose setup uses that same repo id hits `handleRepoChange`'s same-id early return and
+ * would keep the folder's source state. `forceResetStartFrom: isProjectGroupTarget` is what forces
+ * the reset through. Exercised against the real `handleRepoChange`, not its source text.
+ */
+function renderProjectSwitchFromFolderTarget(isProjectGroupTarget: boolean) {
+  const spies = {
+    setBaseBranch: vi.fn(),
+    setLinkedIssue: vi.fn(),
+    setRepoId: vi.fn(),
+    setSparseEnabled: vi.fn(),
+    setStartFromResetHint: vi.fn()
+  }
+  const noop = vi.fn()
+  const shared = {
+    linkedWorkItem: null,
+    setBranchNameOverride: noop,
+    setBranchNameOverridePreservesNameEdits: noop,
+    setForkPushWarning: noop,
+    setLinkedGitLabIssue: noop,
+    setLinkedGitLabMR: noop,
+    setLinkedPR: noop,
+    setLinkedTaskSourceContext: noop,
+    setLinkedWorkItem: noop,
+    setProjectError: noop,
+    setPushTarget: noop,
+    setReuseEligibleBranch: noop,
+    setReuseSelectedBranch: noop,
+    setSelectedProjectHostSetupOverrideId: noop,
+    setSelectedProjectIdOverride: noop,
+    setSparseDirectories: noop,
+    setSparseSelectedPresetId: noop,
+    ...spies
+  }
+  const { result } = renderHook(() => {
+    const { handleRepoChange } = useTargetChangeActions({
+      baseBranch: undefined,
+      branchAutoNameRef: { current: null },
+      decisions: { retargetGitHubPrStartPointSelection: (selection: unknown) => selection },
+      folderSourceRepos: [],
+      hostOptions: [],
+      projectHostSetupOptions: [],
+      // Why: the folder branch already parked the composer on this repo id, so the project switch
+      // resolves to the same value and only the forced reset can clear the folder's state.
+      repoId: 'orca-main',
+      selectedRepoProjectId: PROJECT_ID,
+      setCompareBaseRef: noop,
+      smartGitHubPrStartPointSelectionRef: { current: null },
+      ...shared
+    } as unknown as Parameters<typeof useTargetChangeActions>[0])
+    return useProjectTargetActions({
+      actionableHostIds: new Set<ExecutionHostId>(['local']),
+      eligibleRepos: [makeRepo('orca-main', '/checkouts/main')],
+      handleRepoChange,
+      initialProjectGroupAppliedRef: { current: false },
+      isProjectGroupTarget,
+      projectGroups: [],
+      projectHostSetups: [makeSetup('setup-main', 'local', 'orca-main', '/checkouts/main')],
+      projects: [project],
+      repos: [],
+      selectedWorkspaceTarget: { status: 'unavailable', reason: 'project-has-no-ready-setup' },
+      workspaceHostScope: 'all',
+      setSelectedProjectGroupId: noop,
+      ...shared
+    } as unknown as Parameters<typeof useProjectTargetActions>[0])
+  })
+  return { handleProjectChange: result.current.handleProjectChange, spies }
+}
+
+describe('returning from a folder target to a repo with the same id', () => {
+  it('forces the repo-scoped source reset', () => {
+    const { handleProjectChange, spies } = renderProjectSwitchFromFolderTarget(true)
+
+    handleProjectChange(PROJECT_ID)
+
+    expect(spies.setRepoId).toHaveBeenCalledWith('orca-main')
+    expect(spies.setSparseEnabled).toHaveBeenCalledWith(false)
+    expect(spies.setLinkedIssue).toHaveBeenCalledWith('')
+    expect(spies.setBaseBranch).toHaveBeenCalledWith(undefined)
+    expect(spies.setStartFromResetHint).toHaveBeenCalledWith(null)
+  })
+
+  it('leaves the source state alone when the composer was already on that repo', () => {
+    const { handleProjectChange, spies } = renderProjectSwitchFromFolderTarget(false)
+
+    handleProjectChange(PROJECT_ID)
+
+    expect(spies.setRepoId).toHaveBeenCalledWith('orca-main')
+    expect(spies.setSparseEnabled).not.toHaveBeenCalled()
+    expect(spies.setLinkedIssue).not.toHaveBeenCalled()
+    expect(spies.setBaseBranch).not.toHaveBeenCalled()
+  })
+})

src/renderer/src/hooks/useComposerState-host-context-boundaries.test.ts

@@ -453,15 +453,14 @@ describe('useComposerState host-context boundaries', () => {
     expect(section).toContain("branchAutoNameRef.current = ''")
   })
 
-  it('forces repo-scoped source reset when returning from folder target to a repo with the same id', () => {
+  // The caller half — that a project switch passes `forceResetStartFrom: isProjectGroupTarget`, and
+  // that the reset actually runs — is covered behaviourally against the real `handleRepoChange` in
+  // composer-state/project-target-actions.test.ts ("returning from a folder target to a repo with
+  // the same id"), so it survives renaming the local that holds the resolved repo id.
+  it('keeps the same-id early return escapable', () => {
     const handleRepoChange = COMPOSER_SOURCE.targetChange
     expect(handleRepoChange).toContain('forceResetStartFrom?: boolean')
     expect(handleRepoChange).toContain('value === repoId && !options.forceResetStartFrom')
-
-    const handleProjectChange = COMPOSER_SOURCE.projectTarget
-    expect(handleProjectChange).toContain(
-      'handleRepoChange(nextRepoId, { forceResetStartFrom: isProjectGroupTarget })'
-    )
   })
 
   it('keeps a Linear branch override when its workspace-scoped issue survives a repo change', () => {