fix(auth): report Ctrl-C at the login paste prompt as a cancellation

docs/reference/error-reference.md

@@ -174,7 +174,7 @@ A `ctx.packages` operation (an install, or running a package through the manager
 
 ### CLI.PROMPT_CANCELLED
 
-The user cancelled a prompt: EOF on stdin at a line-rendered prompt, a clack cancel (Ctrl-C at the prompt UI), an abort during a browserWait poll, or — via the service commands' `userCancelledError` — consent declined interactively. Settles with exit 3, the cancellation code, instead of 2. Meta: none.
+The user cancelled a prompt: EOF on stdin at a line-rendered prompt, a clack cancel (Ctrl-C at the prompt UI), an abort during a browserWait poll, Ctrl-C at the `prisma auth login` paste prompt, or — via the service commands' `userCancelledError` — consent declined interactively. Settles with exit 3, the cancellation code, instead of 2. Meta: none.
 
 ### CLI.PROMPT_INVALID
 

packages/cli/src/auth/login.ts

@@ -207,8 +207,15 @@ async function readPastedCallbackUrl(
       signal: options.signal,
     });
   } catch (error) {
-    // The browser callback won the race and aborted us. Stop prompting.
-    if ((error as { name?: string } | null)?.name === "AbortError") return null;
+    if ((error as { name?: string } | null)?.name === "AbortError") {
+      // Our signal aborted: the login is over.
+      if (options.signal.aborted) return null;
+      // readline's own abort is the user's Ctrl-C (raw mode, no SIGINT).
+      throw new CliStructuredError(
+        "CLI.PROMPT_CANCELLED",
+        "Sign-in was cancelled before it completed.",
+      );
+    }
     throw error;
   }
 

packages/cli/tests/auth-login.test.ts

@@ -373,6 +373,28 @@ describe("auth login remote paste flow", () => {
     expect(result.handleCallbackCalls).toBe(2);
   });
 
+  it("reports Ctrl-C at the paste prompt as a cancelled prompt", async () => {
+    await expect(
+      runLogin({
+        ttyInput: true,
+        terminal: true,
+        openUrl: () => {},
+        pasteLines: [CTRL_C],
+      }),
+    ).rejects.toMatchObject({ code: "CLI.PROMPT_CANCELLED" });
+  });
+
+  it("completes through the browser callback while the paste prompt is still waiting", async () => {
+    const result = await runLogin({
+      ttyInput: true,
+      openUrl: async (redirectUri) => {
+        await fetch(`${redirectUri}?code=code_123&state=state_123`);
+      },
+    });
+
+    expect(result.handleCallbackCalls).toBe(1);
+  });
+
   it("surfaces a browser-launch failure when stdin is not a TTY", async () => {
     await expect(
       runLogin({
@@ -401,8 +423,12 @@ describe("auth login remote paste flow", () => {
 const PASTE_CALLBACK_URL =
   "http://localhost:9999/auth/callback?code=code_123&state=state_123";
 
+const CTRL_C = "\x03";
+
 async function runLogin(options: {
   ttyInput: boolean;
+  /** readline only sees keypresses such as Ctrl-C when the output is a TTY. */
+  terminal?: boolean;
   openUrl: (redirectUri: string) => Promise<unknown> | unknown;
   pasteLines?: string[];
 }): Promise<{ handleCallbackCalls: number; output: string }> {
@@ -458,6 +484,9 @@ async function runLogin(options: {
   // line at once loses all but the first across re-prompts.
   const pasteLines = [...(options.pasteLines ?? [])];
   const output = new PassThrough();
+  if (options.terminal) {
+    (output as unknown as { isTTY: boolean }).isTTY = true;
+  }
   const chunks: string[] = [];
   output.on("data", (chunk) => {
     const text = chunk.toString();
@@ -467,7 +496,7 @@ async function runLogin(options: {
       pasteLines.length > 0
     ) {
       const line = pasteLines.shift() as string;
-      queueMicrotask(() => input.write(`${line}\n`));
+      queueMicrotask(() => input.write(line === CTRL_C ? line : `${line}\n`));
     }
   });