diff --git a/scripts/changed-lanes.mjs b/scripts/changed-lanes.mjs
index 92263af7189..eb83d6c2d3a 100644
--- a/scripts/changed-lanes.mjs
+++ b/scripts/changed-lanes.mjs
@@ -1,5 +1,6 @@
 import { execFileSync } from "node:child_process";
 import { appendFileSync } from "node:fs";
+import { booleanFlag, parseFlagArgs, stringFlag } from "./lib/arg-utils.mjs";
 
 const DOCS_PATH_RE = /^(?:docs\/|README\.md$|AGENTS\.md$|.*\.mdx?$)/u;
 const APP_PATH_RE = /^(?:apps\/|Swabble\/|appcast\.xml$)/u;
@@ -221,33 +222,23 @@ function parseArgs(argv) {
     githubOutput: false,
     paths: [],
   };
-  for (let index = 0; index < argv.length; index += 1) {
-    const arg = argv[index];
-    if (arg === "--base") {
-      args.base = argv[index + 1] ?? args.base;
-      index += 1;
-      continue;
-    }
-    if (arg === "--head") {
-      args.head = argv[index + 1] ?? args.head;
-      index += 1;
-      continue;
-    }
-    if (arg === "--staged") {
-      args.staged = true;
-      continue;
-    }
-    if (arg === "--json") {
-      args.json = true;
-      continue;
-    }
-    if (arg === "--github-output") {
-      args.githubOutput = true;
-      continue;
-    }
-    args.paths.push(arg);
-  }
-  return args;
+  return parseFlagArgs(
+    argv,
+    args,
+    [
+      stringFlag("--base", "base"),
+      stringFlag("--head", "head"),
+      booleanFlag("--staged", "staged"),
+      booleanFlag("--json", "json"),
+      booleanFlag("--github-output", "githubOutput"),
+    ],
+    {
+      onUnhandledArg(arg, target) {
+        target.paths.push(arg);
+        return "handled";
+      },
+    },
+  );
 }
 
 function isDirectRun() {
diff --git a/scripts/check-changed.mjs b/scripts/check-changed.mjs
index 8a8609e0c10..3414885d7f8 100644
--- a/scripts/check-changed.mjs
+++ b/scripts/check-changed.mjs
@@ -6,6 +6,8 @@ import {
   listStagedChangedPaths,
   normalizeChangedPath,
 } from "./changed-lanes.mjs";
+import { booleanFlag, parseFlagArgs, stringFlag } from "./lib/arg-utils.mjs";
+import { printTimingSummary } from "./lib/check-timing-summary.mjs";
 
 const ROUTABLE_TEST_PATH_RE = /^(?:src|test|extensions|ui|packages|apps)(?:\/|$)/u;
 
@@ -199,23 +201,7 @@ async function runCommand(command, timings) {
 }
 
 function printSummary(timings, options) {
-  if (!options.timed && timings.every((timing) => timing.status === 0)) {
-    return;
-  }
-  console.error("\n[check:changed] summary");
-  for (const timing of timings) {
-    const status = timing.status === 0 ? "ok" : `failed:${timing.status}`;
-    console.error(
-      `${formatMs(timing.durationMs).padStart(8)}  ${status.padEnd(9)}  ${timing.name}`,
-    );
-  }
-}
-
-function formatMs(durationMs) {
-  if (durationMs < 1000) {
-    return `${Math.round(durationMs)}ms`;
-  }
-  return `${(durationMs / 1000).toFixed(2)}s`;
+  printTimingSummary("check:changed", timings, { skipWhenAllOk: !options.timed });
 }
 
 function parseArgs(argv) {
@@ -227,33 +213,23 @@ function parseArgs(argv) {
     timed: false,
     paths: [],
   };
-  for (let index = 0; index < argv.length; index += 1) {
-    const arg = argv[index];
-    if (arg === "--base") {
-      args.base = argv[index + 1] ?? args.base;
-      index += 1;
-      continue;
-    }
-    if (arg === "--head") {
-      args.head = argv[index + 1] ?? args.head;
-      index += 1;
-      continue;
-    }
-    if (arg === "--staged") {
-      args.staged = true;
-      continue;
-    }
-    if (arg === "--dry-run") {
-      args.dryRun = true;
-      continue;
-    }
-    if (arg === "--timed") {
-      args.timed = true;
-      continue;
-    }
-    args.paths.push(normalizeChangedPath(arg));
-  }
-  return args;
+  return parseFlagArgs(
+    argv,
+    args,
+    [
+      stringFlag("--base", "base"),
+      stringFlag("--head", "head"),
+      booleanFlag("--staged", "staged"),
+      booleanFlag("--dry-run", "dryRun"),
+      booleanFlag("--timed", "timed"),
+    ],
+    {
+      onUnhandledArg(arg, target) {
+        target.paths.push(normalizeChangedPath(arg));
+        return "handled";
+      },
+    },
+  );
 }
 
 function isDirectRun() {
diff --git a/scripts/check.mjs b/scripts/check.mjs
index 007f4be6fa8..3747d4490a9 100644
--- a/scripts/check.mjs
+++ b/scripts/check.mjs
@@ -1,5 +1,6 @@
 import { spawn } from "node:child_process";
 import { performance } from "node:perf_hooks";
+import { printTimingSummary } from "./lib/check-timing-summary.mjs";
 
 export async function main(argv = process.argv.slice(2)) {
   const timed = argv.includes("--timed");
@@ -110,20 +111,7 @@ async function runCommand(command) {
 }
 
 function printSummary(timings) {
-  console.error("\n[check] summary");
-  for (const timing of timings) {
-    const status = timing.status === 0 ? "ok" : `failed:${timing.status}`;
-    console.error(
-      `${formatMs(timing.durationMs).padStart(8)}  ${status.padEnd(9)}  ${timing.name}`,
-    );
-  }
-}
-
-function formatMs(durationMs) {
-  if (durationMs < 1000) {
-    return `${Math.round(durationMs)}ms`;
-  }
-  return `${(durationMs / 1000).toFixed(2)}s`;
+  printTimingSummary("check", timings);
 }
 
 if (import.meta.main) {
diff --git a/scripts/lib/check-timing-summary.mjs b/scripts/lib/check-timing-summary.mjs
new file mode 100644
index 00000000000..955021d4e2d
--- /dev/null
+++ b/scripts/lib/check-timing-summary.mjs
@@ -0,0 +1,20 @@
+export function formatMs(durationMs) {
+  if (durationMs < 1000) {
+    return `${Math.round(durationMs)}ms`;
+  }
+  return `${(durationMs / 1000).toFixed(2)}s`;
+}
+
+export function printTimingSummary(label, timings, options = {}) {
+  if (options.skipWhenAllOk && timings.every((timing) => timing.status === 0)) {
+    return;
+  }
+
+  console.error(`\n[${label}] summary`);
+  for (const timing of timings) {
+    const status = timing.status === 0 ? "ok" : `failed:${timing.status}`;
+    console.error(
+      `${formatMs(timing.durationMs).padStart(8)}  ${status.padEnd(9)}  ${timing.name}`,
+    );
+  }
+}