From 9bb4b21fb59e8bdf44ba608740c6e15e65234452 Mon Sep 17 00:00:00 2001
From: neverland <chenjiahan.jait@bytedance.com>
Date: Tue, 1 Sep 2026 10:18:49 +0800
Subject: [PATCH 1/4] feat(fmt): display millisecond durations

---
 packages/rstack/src/fmt/cli.ts            | 45 ++++++-----------------
 packages/rstack/src/fmt/elapsed.ts        | 35 ++++++++++++++++++
 packages/rstack/tests/cli/fmt/helpers.ts  |  5 ++-
 packages/rstack/tests/fmt/elapsed.test.ts | 18 +++++++++
 4 files changed, 68 insertions(+), 35 deletions(-)
 create mode 100644 packages/rstack/src/fmt/elapsed.ts
 create mode 100644 packages/rstack/tests/fmt/elapsed.test.ts

diff --git a/packages/rstack/src/fmt/cli.ts b/packages/rstack/src/fmt/cli.ts
index ed61c36b..d4dd1f09 100644
--- a/packages/rstack/src/fmt/cli.ts
+++ b/packages/rstack/src/fmt/cli.ts
@@ -8,6 +8,7 @@ import { ensureProjectCacheDir } from '../projectCache.ts';
 import { fmtCacheFileName } from './cacheStore.ts';
 import { resolveFmtConfig } from './config.ts';
 import { discoverFmtFiles } from './discovery.ts';
+import { formatElapsed } from './elapsed.ts';
 import { createRelativePathResolver, toPosixPath } from './pathHelpers.ts';
 import { runFmtFiles } from './runner.ts';
 import type { FmtMode, FmtRunResult, ResolvedFmtConfig } from './types.ts';
@@ -157,34 +158,8 @@ const createDisplayPathResolver = (
   return (filePath) => toPosixPath(resolveRelativePath(filePath));
 };
 
-const prettyTime = (seconds: number): string => {
-  const format = (time: string, unit: 'm' | 's') =>
-    color.bold(`${time}${unit}`);
-
-  if (seconds < 10) {
-    const digits = seconds >= 0.01 ? 2 : 3;
-    return format(seconds.toFixed(digits), 's');
-  }
-
-  if (seconds < 60) {
-    return format(seconds.toFixed(1), 's');
-  }
-
-  const minutes = Math.floor(seconds / 60);
-  const minutesLabel = format(minutes.toFixed(0), 'm');
-  const remainingSeconds = seconds % 60;
-
-  if (remainingSeconds === 0) {
-    return minutesLabel;
-  }
-
-  const secondsLabel = format(
-    remainingSeconds.toFixed(remainingSeconds % 1 === 0 ? 0 : 1),
-    's',
-  );
-
-  return `${minutesLabel} ${secondsLabel}`;
-};
+const prettyTime = (milliseconds: number): string =>
+  color.bold(formatElapsed(milliseconds));
 
 const formatCount = (count: number): string => color.bold(count);
 const formatFileCount = (count: number, isError = false): string => {
@@ -207,7 +182,7 @@ const logFmtResult = (
   mode: FmtMode,
   cwd: string,
   processedFileCount: number,
-  durationSeconds: number,
+  durationMilliseconds: number,
   fixCommand?: string,
 ): void => {
   let writtenCount = 0;
@@ -235,7 +210,7 @@ const logFmtResult = (
     }
 
     const processedFiles = formatFileCount(processedFileCount);
-    const time = prettyTime(durationSeconds);
+    const time = prettyTime(durationMilliseconds);
     const message =
       writtenCount > 0
         ? `Formatted ${formatCount(writtenCount)} of ${processedFiles} in ${time}.`
@@ -255,10 +230,12 @@ const logFmtResult = (
       ? `Run ${color.cyan(fixCommand)} to fix.`
       : `Rerun this command without ${color.cyan('--check')} to fix.`;
     logger.error(`Formatting issues found in ${differentFiles}. ${fixHint}`);
-    logger.info(`Checked ${processedFiles} in ${prettyTime(durationSeconds)}.`);
+    logger.info(
+      `Checked ${processedFiles} in ${prettyTime(durationMilliseconds)}.`,
+    );
   } else if (result.exitCode === 0) {
     logger.success(
-      `Checked ${formatFileCount(processedFileCount)} in ${prettyTime(durationSeconds)}. No issues found.`,
+      `Checked ${formatFileCount(processedFileCount)} in ${prettyTime(durationMilliseconds)}. No issues found.`,
     );
   }
 };
@@ -415,13 +392,13 @@ const runFmtCLI = async (
       return;
     }
 
-    const durationSeconds = (performance.now() - startTime) / 1000;
+    const durationMilliseconds = performance.now() - startTime;
     logFmtResult(
       result,
       mode,
       cwd,
       result.processedFileCount,
-      durationSeconds,
+      durationMilliseconds,
       fixCommand,
     );
     process.exitCode = result.exitCode;
diff --git a/packages/rstack/src/fmt/elapsed.ts b/packages/rstack/src/fmt/elapsed.ts
new file mode 100644
index 00000000..35dd9100
--- /dev/null
+++ b/packages/rstack/src/fmt/elapsed.ts
@@ -0,0 +1,35 @@
+const formatSeconds = (milliseconds: number): string => {
+  const seconds = Math.floor(milliseconds / 1000);
+  const remainder = milliseconds % 1000;
+
+  if (remainder === 0) {
+    return `${seconds}s`;
+  }
+
+  const fraction = remainder.toString().padStart(3, '0').replace(/0+$/, '');
+  return `${seconds}.${fraction}s`;
+};
+
+/** Formats elapsed milliseconds after rounding to millisecond precision. */
+const formatElapsed = (milliseconds: number): string => {
+  if (milliseconds < 1) {
+    return '<1ms';
+  }
+
+  const roundedMilliseconds = Math.round(milliseconds);
+  if (roundedMilliseconds < 1000) {
+    return `${roundedMilliseconds}ms`;
+  }
+
+  const hours = Math.floor(roundedMilliseconds / 3_600_000);
+  const minutes = Math.floor(roundedMilliseconds / 60_000) % 60;
+  const seconds = formatSeconds(roundedMilliseconds % 60_000);
+
+  if (hours > 0) {
+    return `${hours}h${minutes}m${seconds}`;
+  }
+
+  return minutes > 0 ? `${minutes}m${seconds}` : seconds;
+};
+
+export { formatElapsed };
diff --git a/packages/rstack/tests/cli/fmt/helpers.ts b/packages/rstack/tests/cli/fmt/helpers.ts
index d3b62229..9a51e0fb 100644
--- a/packages/rstack/tests/cli/fmt/helpers.ts
+++ b/packages/rstack/tests/cli/fmt/helpers.ts
@@ -42,7 +42,10 @@ export const createCliEnv = (): NodeJS.ProcessEnv => {
 };
 
 export const normalizeDuration = (output: string): string =>
-  output.replace(/\d+m(?: \d+(?:\.\d+)?s)?|\d+(?:\.\d+)?s/g, '<duration>');
+  output.replace(
+    /<1ms|\d+ms|\d+h\d+m\d+(?:\.\d+)?s|\d+m\d+(?:\.\d+)?s|\d+(?:\.\d+)?s/g,
+    '<duration>',
+  );
 
 export const expectWriteSummary = (
   output: string,
diff --git a/packages/rstack/tests/fmt/elapsed.test.ts b/packages/rstack/tests/fmt/elapsed.test.ts
new file mode 100644
index 00000000..a0ecbe03
--- /dev/null
+++ b/packages/rstack/tests/fmt/elapsed.test.ts
@@ -0,0 +1,18 @@
+import { expect, test } from 'rstack/test';
+import { formatElapsed } from '../../src/fmt/elapsed.ts';
+
+test.each([
+  [0, '<1ms'],
+  [0.999, '<1ms'],
+  [1, '1ms'],
+  [29.6, '30ms'],
+  [999.4, '999ms'],
+  [999.6, '1s'],
+  [1_390, '1.39s'],
+  [1_234, '1.234s'],
+  [60_000, '1m0s'],
+  [60_123, '1m0.123s'],
+  [3_661_234, '1h1m1.234s'],
+] as const)('formats %sms as %s', (milliseconds, expected) => {
+  expect(formatElapsed(milliseconds)).toBe(expected);
+});

From c77751aeba0f3eb8c7b3663e31ae9d3b9591a6ba Mon Sep 17 00:00:00 2001
From: neverland <chenjiahan.jait@bytedance.com>
Date: Tue, 1 Sep 2026 10:35:52 +0800
Subject: [PATCH 2/4] refactor(fmt): rename duration formatter

---
 packages/rstack/src/fmt/cli.ts                              | 4 ++--
 packages/rstack/src/fmt/{elapsed.ts => duration.ts}         | 6 +++---
 .../rstack/tests/fmt/{elapsed.test.ts => duration.test.ts}  | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)
 rename packages/rstack/src/fmt/{elapsed.ts => duration.ts} (83%)
 rename packages/rstack/tests/fmt/{elapsed.test.ts => duration.test.ts} (74%)

diff --git a/packages/rstack/src/fmt/cli.ts b/packages/rstack/src/fmt/cli.ts
index d4dd1f09..463bbbb2 100644
--- a/packages/rstack/src/fmt/cli.ts
+++ b/packages/rstack/src/fmt/cli.ts
@@ -8,7 +8,7 @@ import { ensureProjectCacheDir } from '../projectCache.ts';
 import { fmtCacheFileName } from './cacheStore.ts';
 import { resolveFmtConfig } from './config.ts';
 import { discoverFmtFiles } from './discovery.ts';
-import { formatElapsed } from './elapsed.ts';
+import { formatDuration } from './duration.ts';
 import { createRelativePathResolver, toPosixPath } from './pathHelpers.ts';
 import { runFmtFiles } from './runner.ts';
 import type { FmtMode, FmtRunResult, ResolvedFmtConfig } from './types.ts';
@@ -159,7 +159,7 @@ const createDisplayPathResolver = (
 };
 
 const prettyTime = (milliseconds: number): string =>
-  color.bold(formatElapsed(milliseconds));
+  color.bold(formatDuration(milliseconds));
 
 const formatCount = (count: number): string => color.bold(count);
 const formatFileCount = (count: number, isError = false): string => {
diff --git a/packages/rstack/src/fmt/elapsed.ts b/packages/rstack/src/fmt/duration.ts
similarity index 83%
rename from packages/rstack/src/fmt/elapsed.ts
rename to packages/rstack/src/fmt/duration.ts
index 35dd9100..4ea5449e 100644
--- a/packages/rstack/src/fmt/elapsed.ts
+++ b/packages/rstack/src/fmt/duration.ts
@@ -10,8 +10,8 @@ const formatSeconds = (milliseconds: number): string => {
   return `${seconds}.${fraction}s`;
 };
 
-/** Formats elapsed milliseconds after rounding to millisecond precision. */
-const formatElapsed = (milliseconds: number): string => {
+/** Formats a duration after rounding to millisecond precision. */
+const formatDuration = (milliseconds: number): string => {
   if (milliseconds < 1) {
     return '<1ms';
   }
@@ -32,4 +32,4 @@ const formatElapsed = (milliseconds: number): string => {
   return minutes > 0 ? `${minutes}m${seconds}` : seconds;
 };
 
-export { formatElapsed };
+export { formatDuration };
diff --git a/packages/rstack/tests/fmt/elapsed.test.ts b/packages/rstack/tests/fmt/duration.test.ts
similarity index 74%
rename from packages/rstack/tests/fmt/elapsed.test.ts
rename to packages/rstack/tests/fmt/duration.test.ts
index a0ecbe03..4800ab33 100644
--- a/packages/rstack/tests/fmt/elapsed.test.ts
+++ b/packages/rstack/tests/fmt/duration.test.ts
@@ -1,5 +1,5 @@
 import { expect, test } from 'rstack/test';
-import { formatElapsed } from '../../src/fmt/elapsed.ts';
+import { formatDuration } from '../../src/fmt/duration.ts';
 
 test.each([
   [0, '<1ms'],
@@ -14,5 +14,5 @@ test.each([
   [60_123, '1m0.123s'],
   [3_661_234, '1h1m1.234s'],
 ] as const)('formats %sms as %s', (milliseconds, expected) => {
-  expect(formatElapsed(milliseconds)).toBe(expected);
+  expect(formatDuration(milliseconds)).toBe(expected);
 });

From aedb0e226cd22d3439b4efdd90bcaa0970a1aac7 Mon Sep 17 00:00:00 2001
From: neverland <chenjiahan.jait@bytedance.com>
Date: Tue, 1 Sep 2026 10:39:35 +0800
Subject: [PATCH 3/4] refactor(fmt): simplify duration formatting

---
 packages/rstack/src/fmt/cli.ts | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/packages/rstack/src/fmt/cli.ts b/packages/rstack/src/fmt/cli.ts
index 463bbbb2..40518c0f 100644
--- a/packages/rstack/src/fmt/cli.ts
+++ b/packages/rstack/src/fmt/cli.ts
@@ -158,9 +158,6 @@ const createDisplayPathResolver = (
   return (filePath) => toPosixPath(resolveRelativePath(filePath));
 };
 
-const prettyTime = (milliseconds: number): string =>
-  color.bold(formatDuration(milliseconds));
-
 const formatCount = (count: number): string => color.bold(count);
 const formatFileCount = (count: number, isError = false): string => {
   const formattedCount = formatCount(count);
@@ -204,13 +201,18 @@ const logFmtResult = (
     }
   }
 
+  if (mode === 'list-different') {
+    return;
+  }
+
+  const time = color.bold(formatDuration(durationMilliseconds));
+
   if (mode === 'write') {
     if (writtenCount === 0 && result.exitCode !== 0) {
       return;
     }
 
     const processedFiles = formatFileCount(processedFileCount);
-    const time = prettyTime(durationMilliseconds);
     const message =
       writtenCount > 0
         ? `Formatted ${formatCount(writtenCount)} of ${processedFiles} in ${time}.`
@@ -219,10 +221,6 @@ const logFmtResult = (
     return;
   }
 
-  if (mode !== 'check') {
-    return;
-  }
-
   if (differentCount > 0) {
     const differentFiles = formatFileCount(differentCount, true);
     const processedFiles = formatFileCount(processedFileCount);
@@ -230,12 +228,10 @@ const logFmtResult = (
       ? `Run ${color.cyan(fixCommand)} to fix.`
       : `Rerun this command without ${color.cyan('--check')} to fix.`;
     logger.error(`Formatting issues found in ${differentFiles}. ${fixHint}`);
-    logger.info(
-      `Checked ${processedFiles} in ${prettyTime(durationMilliseconds)}.`,
-    );
+    logger.info(`Checked ${processedFiles} in ${time}.`);
   } else if (result.exitCode === 0) {
     logger.success(
-      `Checked ${formatFileCount(processedFileCount)} in ${prettyTime(durationMilliseconds)}. No issues found.`,
+      `Checked ${formatFileCount(processedFileCount)} in ${time}. No issues found.`,
     );
   }
 };

From b049451d5a86d9167c96a1690056fbe7d7da9170 Mon Sep 17 00:00:00 2001
From: neverland <chenjiahan.jait@bytedance.com>
Date: Tue, 1 Sep 2026 10:48:01 +0800
Subject: [PATCH 4/4] fix(fmt): preserve duration precision

---
 packages/rstack/src/fmt/duration.ts        | 37 +++++++++++-----------
 packages/rstack/tests/cli/fmt/helpers.ts   |  2 +-
 packages/rstack/tests/fmt/duration.test.ts | 11 ++++---
 3 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/packages/rstack/src/fmt/duration.ts b/packages/rstack/src/fmt/duration.ts
index 4ea5449e..c093fab0 100644
--- a/packages/rstack/src/fmt/duration.ts
+++ b/packages/rstack/src/fmt/duration.ts
@@ -1,16 +1,4 @@
-const formatSeconds = (milliseconds: number): string => {
-  const seconds = Math.floor(milliseconds / 1000);
-  const remainder = milliseconds % 1000;
-
-  if (remainder === 0) {
-    return `${seconds}s`;
-  }
-
-  const fraction = remainder.toString().padStart(3, '0').replace(/0+$/, '');
-  return `${seconds}.${fraction}s`;
-};
-
-/** Formats a duration after rounding to millisecond precision. */
+/** Formats sub-second durations in milliseconds and preserves the existing longer-duration format. */
 const formatDuration = (milliseconds: number): string => {
   if (milliseconds < 1) {
     return '<1ms';
@@ -21,15 +9,26 @@ const formatDuration = (milliseconds: number): string => {
     return `${roundedMilliseconds}ms`;
   }
 
-  const hours = Math.floor(roundedMilliseconds / 3_600_000);
-  const minutes = Math.floor(roundedMilliseconds / 60_000) % 60;
-  const seconds = formatSeconds(roundedMilliseconds % 60_000);
+  const seconds = milliseconds / 1000;
+  if (seconds < 10) {
+    return `${seconds.toFixed(2)}s`;
+  }
+
+  if (seconds < 60) {
+    return `${seconds.toFixed(1)}s`;
+  }
+
+  const minutes = Math.floor(seconds / 60);
+  const remainingSeconds = seconds % 60;
 
-  if (hours > 0) {
-    return `${hours}h${minutes}m${seconds}`;
+  if (remainingSeconds === 0) {
+    return `${minutes}m`;
   }
 
-  return minutes > 0 ? `${minutes}m${seconds}` : seconds;
+  const secondsLabel = remainingSeconds.toFixed(
+    remainingSeconds % 1 === 0 ? 0 : 1,
+  );
+  return `${minutes}m ${secondsLabel}s`;
 };
 
 export { formatDuration };
diff --git a/packages/rstack/tests/cli/fmt/helpers.ts b/packages/rstack/tests/cli/fmt/helpers.ts
index 9a51e0fb..5086ce5d 100644
--- a/packages/rstack/tests/cli/fmt/helpers.ts
+++ b/packages/rstack/tests/cli/fmt/helpers.ts
@@ -43,7 +43,7 @@ export const createCliEnv = (): NodeJS.ProcessEnv => {
 
 export const normalizeDuration = (output: string): string =>
   output.replace(
-    /<1ms|\d+ms|\d+h\d+m\d+(?:\.\d+)?s|\d+m\d+(?:\.\d+)?s|\d+(?:\.\d+)?s/g,
+    /<1ms|\d+ms|\d+m(?: \d+(?:\.\d+)?s)?|\d+(?:\.\d+)?s/g,
     '<duration>',
   );
 
diff --git a/packages/rstack/tests/fmt/duration.test.ts b/packages/rstack/tests/fmt/duration.test.ts
index 4800ab33..ad208cbf 100644
--- a/packages/rstack/tests/fmt/duration.test.ts
+++ b/packages/rstack/tests/fmt/duration.test.ts
@@ -7,12 +7,13 @@ test.each([
   [1, '1ms'],
   [29.6, '30ms'],
   [999.4, '999ms'],
-  [999.6, '1s'],
+  [999.6, '1.00s'],
   [1_390, '1.39s'],
-  [1_234, '1.234s'],
-  [60_000, '1m0s'],
-  [60_123, '1m0.123s'],
-  [3_661_234, '1h1m1.234s'],
+  [1_234, '1.23s'],
+  [12_340, '12.3s'],
+  [60_000, '1m'],
+  [60_123, '1m 0.1s'],
+  [3_661_234, '61m 1.2s'],
 ] as const)('formats %sms as %s', (milliseconds, expected) => {
   expect(formatDuration(milliseconds)).toBe(expected);
 });