fix(polling): move spinner from stderr to stdout to prevent consola collision

src/lib/polling.ts

@@ -6,6 +6,7 @@
  */
 
 import { TimeoutError } from "./errors.js";
+import { isPlainOutput } from "./formatters/plain-detect.js";
 import {
   formatProgressLine,
   truncateProgressMessage,
@@ -82,7 +83,8 @@ export async function poll<T>(options: PollOptions<T>): Promise<T> {
   } = options;
 
   const startTime = Date.now();
-  const spinner = json ? null : startSpinner(initialMessage);
+  const suppress = json || isPlainOutput();
+  const spinner = suppress ? null : startSpinner(initialMessage);
 
   try {
     while (Date.now() - startTime < timeoutMs) {
@@ -105,17 +107,21 @@ export async function poll<T>(options: PollOptions<T>): Promise<T> {
     throw new TimeoutError(timeoutMessage, timeoutHint);
   } finally {
     spinner?.stop();
-    if (!json) {
-      process.stderr.write("\n");
+    if (!suppress) {
+      process.stdout.write("\n");
     }
   }
 }
 
 /**
- * Start an animated spinner that writes progress to stderr.
+ * Start an animated spinner that writes progress to stdout.
+ *
+ * Uses stdout so the spinner doesn't collide with consola log messages
+ * on stderr. The spinner is erased before command output is written,
+ * and is suppressed entirely in JSON mode and when stdout is not a TTY.
  *
  * Returns a controller with `setMessage` to update the displayed text
- * and `stop` to halt the animation. Writes directly to `process.stderr`.
+ * and `stop` to halt the animation.
  */
 function startSpinner(initialMessage: string): {
   setMessage: (msg: string) => void;
@@ -130,7 +136,7 @@ function startSpinner(initialMessage: string): {
       return;
     }
     const display = truncateProgressMessage(currentMessage);
-    process.stderr.write(`\r\x1b[K${formatProgressLine(display, tick)}`);
+    process.stdout.write(`\r\x1b[K${formatProgressLine(display, tick)}`);
     tick += 1;
     setTimeout(scheduleFrame, ANIMATION_INTERVAL_MS).unref();
   };
@@ -158,15 +164,15 @@ export type WithProgressOptions = {
 };
 
 /**
- * Run an async operation with an animated spinner on stderr.
+ * Run an async operation with an animated spinner on stdout.
  *
  * The spinner uses the same braille frames as the Seer polling spinner,
  * giving a consistent look across all CLI commands. Progress output goes
- * to stderr, so it never contaminates stdout (safe to use alongside JSON output).
+ * to stdout so it doesn't collide with consola log messages on stderr.
  *
- * When `options.json` is true the spinner is suppressed entirely, matching
- * the behaviour of {@link poll}. This avoids noisy ANSI escape sequences on
- * stderr when agents or CI pipelines consume `--json` output.
+ * The spinner is suppressed when:
+ * - `options.json` is true (JSON mode — no ANSI noise for agents/CI)
+ * - stdout is not a TTY / plain output mode is active (piped output)
  *
  * The callback receives a `setMessage` function to update the displayed
  * message as work progresses (e.g. to show page counts during pagination).
@@ -193,10 +199,10 @@ export async function withProgress<T>(
   options: WithProgressOptions,
   fn: (setMessage: (msg: string) => void) => Promise<T>
 ): Promise<T> {
-  if (options.json) {
-    // JSON mode: skip the spinner entirely, pass a no-op setMessage
+  if (options.json || isPlainOutput()) {
+    // JSON mode or non-TTY: skip the spinner entirely, pass a no-op setMessage
     return fn(() => {
-      /* spinner suppressed in JSON mode */
+      /* spinner suppressed */
     });
   }
 
@@ -206,6 +212,6 @@ export async function withProgress<T>(
     return await fn(spinner.setMessage);
   } finally {
     spinner.stop();
-    process.stderr.write("\r\x1b[K");
+    process.stdout.write("\r\x1b[K");
   }
 }

test/commands/cli/upgrade.test.ts

@@ -66,18 +66,27 @@ function createMockContext(
     ...overrides.env,
   };
 
-  // Force plain output so formatUpgradeResult renders raw markdown
-  // instead of ANSI-styled output in TTY mode.
+  // Force rich output so the spinner (which uses isPlainOutput() to decide
+  // whether to render) is not suppressed in non-TTY test environments.
+  // The formatUpgradeResult output will contain ANSI codes, but test
+  // assertions use toContain() which matches through them.
   const origPlain = process.env.SENTRY_PLAIN_OUTPUT;
-  process.env.SENTRY_PLAIN_OUTPUT = "1";
+  process.env.SENTRY_PLAIN_OUTPUT = "0";
 
   // Capture consola output (routed to process.stderr)
-  const origWrite = process.stderr.write.bind(process.stderr);
+  const origStderrWrite = process.stderr.write.bind(process.stderr);
   process.stderr.write = ((chunk: string | Uint8Array) => {
     stderrChunks.push(String(chunk));
     return true;
   }) as typeof process.stderr.write;
 
+  // Capture spinner output (routed to process.stdout)
+  const origStdoutWrite = process.stdout.write.bind(process.stdout);
+  process.stdout.write = ((chunk: string | Uint8Array) => {
+    stdoutChunks.push(String(chunk));
+    return true;
+  }) as typeof process.stdout.write;
+
   const stdoutWriter = {
     write: (s: string) => {
       stdoutChunks.push(s);
@@ -130,7 +139,8 @@ function createMockContext(
     getOutput: () => stderrChunks.join("") + stdoutChunks.join(""),
     errors,
     restore: () => {
-      process.stderr.write = origWrite;
+      process.stderr.write = origStderrWrite;
+      process.stdout.write = origStdoutWrite;
       if (origPlain === undefined) {
         delete process.env.SENTRY_PLAIN_OUTPUT;
       } else {
@@ -731,7 +741,7 @@ describe("sentry cli upgrade — curl full upgrade path (Bun.spawn spy)", () =>
     await run(app, ["cli", "upgrade", "--method", "curl"], context);
 
     const combined = getOutput();
-    // Spinner progress messages written to stderr
+    // Spinner progress messages written to stdout
     expect(combined).toContain("Checking for updates");
     expect(combined).toContain("Downloading 99.99.99");
     expect(combined).toContain("Upgraded to");
@@ -857,7 +867,7 @@ describe("sentry cli upgrade — curl full upgrade path (Bun.spawn spy)", () =>
     const combined = getOutput();
     // With --force, should NOT show "Already up to date"
     expect(combined).not.toContain("Already up to date");
-    // Should proceed to download and succeed (spinner messages on stderr)
+    // Should proceed to download and succeed (spinner messages on stdout)
     expect(combined).toContain(`Downloading ${CLI_VERSION}`);
     expect(combined).toContain("Upgraded to");
     expect(combined).toContain(CLI_VERSION);

test/commands/issue/utils.test.ts

@@ -1058,16 +1058,20 @@ describe("pollAutofixState", () => {
     expect(fetchCount).toBe(2);
   });
 
-  test("writes progress to stderr when not in JSON mode", async () => {
-    let stderrOutput = "";
+  test("writes progress to stdout when not in JSON mode", async () => {
+    let stdoutOutput = "";
     let fetchCount = 0;
 
-    // Spy on process.stderr.write to capture spinner output
-    const origWrite = process.stderr.write.bind(process.stderr);
-    process.stderr.write = ((chunk: string | Uint8Array) => {
-      stderrOutput += String(chunk);
+    // Force rich output so the spinner isn't suppressed in non-TTY test env
+    const origPlain = process.env.SENTRY_PLAIN_OUTPUT;
+    process.env.SENTRY_PLAIN_OUTPUT = "0";
+
+    // Spy on process.stdout.write to capture spinner output
+    const origWrite = process.stdout.write.bind(process.stdout);
+    process.stdout.write = ((chunk: string | Uint8Array) => {
+      stdoutOutput += String(chunk);
       return true;
-    }) as typeof process.stderr.write;
+    }) as typeof process.stdout.write;
 
     try {
       // Return PROCESSING first to allow animation interval to fire,
@@ -1127,9 +1131,14 @@ describe("pollAutofixState", () => {
         pollIntervalMs: 100, // Allow animation interval (80ms) to fire
       });
 
-      expect(stderrOutput).toContain("Analyzing");
+      expect(stdoutOutput).toContain("Analyzing");
     } finally {
-      process.stderr.write = origWrite;
+      process.stdout.write = origWrite;
+      if (origPlain === undefined) {
+        delete process.env.SENTRY_PLAIN_OUTPUT;
+      } else {
+        process.env.SENTRY_PLAIN_OUTPUT = origPlain;
+      }
     }
   });
 
@@ -1505,16 +1514,20 @@ describe("ensureRootCauseAnalysis", () => {
     expect(triggerCalled).toBe(true); // Should trigger even though state exists
   });
 
-  test("writes progress messages to stderr when not in JSON mode", async () => {
-    let stderrOutput = "";
+  test("writes progress messages to stdout when not in JSON mode", async () => {
+    let stdoutOutput = "";
     let triggerCalled = false;
 
-    // Spy on process.stderr.write to capture logger output
-    const origWrite = process.stderr.write.bind(process.stderr);
-    process.stderr.write = ((chunk: string | Uint8Array) => {
-      stderrOutput += String(chunk);
+    // Force rich output so the spinner isn't suppressed in non-TTY test env
+    const origPlain = process.env.SENTRY_PLAIN_OUTPUT;
+    process.env.SENTRY_PLAIN_OUTPUT = "0";
+
+    // Spy on process.stdout.write to capture spinner output
+    const origWrite = process.stdout.write.bind(process.stdout);
+    process.stdout.write = ((chunk: string | Uint8Array) => {
+      stdoutOutput += String(chunk);
       return true;
-    }) as typeof process.stderr.write;
+    }) as typeof process.stdout.write;
 
     try {
       // @ts-expect-error - partial mock
@@ -1566,11 +1579,15 @@ describe("ensureRootCauseAnalysis", () => {
         json: false, // Not JSON mode, should output progress
       });
 
-      // The logger.info() messages go through consola and the poll spinner
-      // writes directly to stderr — check for the spinner's initial message
-      expect(stderrOutput).toContain("Waiting for analysis");
+      // The poll spinner writes to stdout — check for the spinner's initial message
+      expect(stdoutOutput).toContain("Waiting for analysis");
     } finally {
-      process.stderr.write = origWrite;
+      process.stdout.write = origWrite;
+      if (origPlain === undefined) {
+        delete process.env.SENTRY_PLAIN_OUTPUT;
+      } else {
+        process.env.SENTRY_PLAIN_OUTPUT = origPlain;
+      }
     }
   });
 });