fix(vcs): keep the current branch name in New Branch even though it exists (#1305)

New Branch dropped its suggestion when validateBranchName rejected it, and the current branch always exists, so a plain New Branch from HEAD always opened empty; the test never seeded the local branches. The suggestion is kept, the dialog shows that the branch exists from the start and Create stays disabled until the name changes; other prefilled prompts (Rename Branch) keep showing errors only after editing.

src/features/vcs/__tests__/branchOps.test.ts

@@ -1,5 +1,5 @@
 import { beforeEach, expect, it, vi } from "vitest";
-import type { BranchInfo } from "@/bindings";
+import type { Branch, BranchInfo } from "@/bindings";
 const mocks = vi.hoisted(() => ({ prompt: vi.fn() }));
 vi.mock("../dialogs", async (original) => ({
   ...(await original<typeof import("../dialogs")>()),
@@ -17,9 +17,25 @@ const branch = (head: string | null): BranchInfo => ({
   operation: null,
 });
 
+const local = (name: string, current = false): Branch => ({
+  name,
+  remote: false,
+  current,
+  upstream: null,
+  ahead: 0,
+  behind: 0,
+  lastCommitMs: null,
+});
+
 beforeEach(() => {
   vi.clearAllMocks();
-  useVcs.setState({ root: "/p", repo: "/p/front", branch: branch("feature/ui") });
+  // The current branch is always among the local branches, so the suggestion names an existing one.
+  useVcs.setState({
+    root: "/p",
+    repo: "/p/front",
+    branch: branch("feature/ui"),
+    branches: [local("feature/ui", true), local("main")],
+  });
   // Cancel: only what the dialog was offered matters here, not its outcome.
   mocks.prompt.mockResolvedValue(null);
 });
@@ -27,6 +43,7 @@ beforeEach(() => {
 it("prefills a plain New Branch with the current branch name", async () => {
   await newBranch();
   expect(mocks.prompt.mock.calls[0]?.[0].initial).toBe("feature/ui");
+  expect(mocks.prompt.mock.calls[0]?.[0].validateInitial).toBe(true);
 });
 
 it("prefills nothing when HEAD is detached", async () => {

src/features/vcs/branchOps.ts

@@ -156,10 +156,12 @@ export async function newBranch(from?: string) {
   const r = await promptText({
     title: from ? tx`Create New Branch from ${from}` : "Create New Branch",
     label: "New branch name:",
-    initial: suggestion && !validateBranchName(suggestion) ? suggestion : "",
+    // Kept even when that branch exists (the current one always does): the user edits it.
+    initial: suggestion,
     mono: true,
     okLabel: "Create",
     validate: validateBranchName,
+    validateInitial: true,
     checkbox: { label: "Checkout branch", initial: true },
   });
   if (!r) return;
@@ -371,6 +373,7 @@ export async function newBranchInRepos(roots: readonly string[], from?: string)
     mono: true,
     okLabel: "Create",
     validate: validateBranchName,
+    validateInitial: true,
     checkbox: { label: "Checkout branch", initial: true },
   });
   if (!r) return;

src/features/vcs/dialogs.tsx

@@ -43,6 +43,8 @@ export interface PromptOptions {
   mono?: boolean;
   /** Returns an error message, or null when valid. */
   validate?: (value: string) => string | null;
+  /** Show the prefilled value's problem (e.g. the branch exists) before it is edited. */
+  validateInitial?: boolean;
   /** Optional checkbox below the field. */
   checkbox?: { label: string; initial: boolean };
 }
@@ -70,7 +72,7 @@ function PromptDialog(props: PromptOptions & { onDone: (r: PromptResult | null)
   const { title, label, initial = "", placeholder, okLabel = "OK", mono, validate, checkbox, onDone } = props;
   const [value, setValue] = useState(initial);
   const [checked, setChecked] = useState(checkbox?.initial ?? false);
-  const [touched, setTouched] = useState(false);
+  const [touched, setTouched] = useState(!!props.validateInitial && initial !== "");
   const error = validate ? validate(value) : value.trim() ? null : "Value must not be empty";
   const submit = () => {
     setTouched(true);