ci: relax file-size ceilings by surface

AGENTS.md

@@ -586,8 +586,8 @@ The mobile app lives in `mobile/` — a Flutter app using Riverpod + Hooks.
   over raw `Theme.of(context)` calls.
 - **Keep widgets small and composable.** One public widget per file; push
   private sub-widgets (`_Foo`) into sibling `part` files under a
-  `<page>/` folder rather than growing the page file. Hard ceiling:
-  **1000 lines/file**, enforced across Desktop, Web, and Mobile by the
+  `<page>/` folder rather than growing the page file. Mobile's hard ceiling is
+  **1200 lines/file**, enforced with the other surface-specific limits by the
   repository-level `just file-size-check` gate (`just check`, CI, and every
   pre-push). If the guard trips, **split the file — never bump the limit or add
   an override to slip under it.**

desktop/scripts/check-file-sizes.mjs

@@ -1,61 +1,17 @@
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 import { runFileSizeCheck } from "../../scripts/check-file-sizes-core.mjs";
+import { rules } from "./file-size-policy.mjs";
 
-const __dirname = path.dirname(fileURLToPath(import.meta.url));
-const projectRoot = path.resolve(__dirname, "..");
+const scriptPath = fileURLToPath(import.meta.url);
+const projectRoot = path.resolve(path.dirname(scriptPath), "..");
 
-const MAX_LINES = 1000;
-
-const rules = [
-  { root: "src-tauri/src", extensions: new Set([".rs"]), maxLines: MAX_LINES },
-  // Workspace member crates. Without this the ratchet's only Rust root is
-  // `src-tauri/src`, and a crate under `src-tauri/crates/` is born outside the
-  // repo's one size discipline -- silently, since the check still exits 0.
-  {
-    root: "src-tauri/crates",
-    extensions: new Set([".rs"]),
-    maxLines: MAX_LINES,
-  },
-  {
-    root: "src/app",
-    extensions: new Set([".ts", ".tsx"]),
-    maxLines: MAX_LINES,
-  },
-  {
-    root: "src/features",
-    extensions: new Set([".ts", ".tsx"]),
-    maxLines: MAX_LINES,
-  },
-  {
-    root: "src/shared/api",
-    extensions: new Set([".ts", ".tsx"]),
-    maxLines: MAX_LINES,
-  },
-  {
-    root: "src/shared/context",
-    extensions: new Set([".ts", ".tsx"]),
-    maxLines: MAX_LINES,
-  },
-  {
-    root: "src/shared/lib",
-    extensions: new Set([".ts", ".tsx"]),
-    maxLines: MAX_LINES,
-  },
-  {
-    root: "src/shared/ui",
-    extensions: new Set([".ts", ".tsx"]),
-    maxLines: MAX_LINES,
-  },
-  {
-    root: "src/shared/styles",
-    extensions: new Set([".css"]),
-    maxLines: MAX_LINES,
-  },
-];
-
-await runFileSizeCheck({
+export const policy = {
   projectRoot,
   rules,
   label: "Desktop",
-});
+};
+
+if (process.argv[1] && path.resolve(process.argv[1]) === scriptPath) {
+  await runFileSizeCheck(policy);
+}

desktop/scripts/file-size-policy.mjs

@@ -0,0 +1,53 @@
+const DESKTOP_FRONTEND_MAX_LINES = 1200;
+const DESKTOP_RUST_MAX_LINES = 1500;
+
+export const rules = [
+  {
+    root: "src-tauri/src",
+    extensions: new Set([".rs"]),
+    maxLines: DESKTOP_RUST_MAX_LINES,
+  },
+  // Workspace member crates. Without this the ratchet's only Rust root is
+  // `src-tauri/src`, and a crate under `src-tauri/crates/` is born outside the
+  // repo's one size discipline -- silently, since the check still exits 0.
+  {
+    root: "src-tauri/crates",
+    extensions: new Set([".rs"]),
+    maxLines: DESKTOP_RUST_MAX_LINES,
+  },
+  {
+    root: "src/app",
+    extensions: new Set([".ts", ".tsx"]),
+    maxLines: DESKTOP_FRONTEND_MAX_LINES,
+  },
+  {
+    root: "src/features",
+    extensions: new Set([".ts", ".tsx"]),
+    maxLines: DESKTOP_FRONTEND_MAX_LINES,
+  },
+  {
+    root: "src/shared/api",
+    extensions: new Set([".ts", ".tsx"]),
+    maxLines: DESKTOP_FRONTEND_MAX_LINES,
+  },
+  {
+    root: "src/shared/context",
+    extensions: new Set([".ts", ".tsx"]),
+    maxLines: DESKTOP_FRONTEND_MAX_LINES,
+  },
+  {
+    root: "src/shared/lib",
+    extensions: new Set([".ts", ".tsx"]),
+    maxLines: DESKTOP_FRONTEND_MAX_LINES,
+  },
+  {
+    root: "src/shared/ui",
+    extensions: new Set([".ts", ".tsx"]),
+    maxLines: DESKTOP_FRONTEND_MAX_LINES,
+  },
+  {
+    root: "src/shared/styles",
+    extensions: new Set([".css"]),
+    maxLines: DESKTOP_FRONTEND_MAX_LINES,
+  },
+];

mobile/scripts/check-file-sizes.mjs

@@ -1,22 +1,17 @@
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 import { runFileSizeCheck } from "../../scripts/check-file-sizes-core.mjs";
+import { rules } from "./file-size-policy.mjs";
 
-const __dirname = path.dirname(fileURLToPath(import.meta.url));
-const projectRoot = path.resolve(__dirname, "..");
+const scriptPath = fileURLToPath(import.meta.url);
+const projectRoot = path.resolve(path.dirname(scriptPath), "..");
 
-const MAX_LINES = 1000;
-
-const rules = [
-  {
-    root: "lib",
-    extensions: new Set([".dart"]),
-    maxLines: MAX_LINES,
-  },
-];
-
-await runFileSizeCheck({
+export const policy = {
   projectRoot,
   rules,
   label: "Mobile",
-});
+};
+
+if (process.argv[1] && path.resolve(process.argv[1]) === scriptPath) {
+  await runFileSizeCheck(policy);
+}

mobile/scripts/file-size-policy.mjs

@@ -0,0 +1,7 @@
+export const rules = [
+  {
+    root: "lib",
+    extensions: new Set([".dart"]),
+    maxLines: 1200,
+  },
+];

scripts/check-file-sizes-core.test.mjs

@@ -1,9 +1,18 @@
 import assert from "node:assert/strict";
-import { execFileSync } from "node:child_process";
-import { mkdtempSync } from "node:fs";
+import { execFileSync, spawnSync } from "node:child_process";
+import {
+  copyFileSync,
+  mkdirSync,
+  mkdtempSync,
+  realpathSync,
+  writeFileSync,
+} from "node:fs";
 import { tmpdir } from "node:os";
 import path from "node:path";
 import test from "node:test";
+import { policy as desktopPolicy } from "../desktop/scripts/check-file-sizes.mjs";
+import { policy as mobilePolicy } from "../mobile/scripts/check-file-sizes.mjs";
+import { policy as webPolicy } from "../web/scripts/check-file-sizes.mjs";
 import {
   allowedLineCount,
   countLines,
@@ -12,6 +21,8 @@ import {
   resolveBaseRef,
 } from "./check-file-sizes-core.mjs";
 
+const repoRoot = path.resolve(import.meta.dirname, "..");
+
 function git(repo, ...args) {
   // These fixture repositories inherit both hook configuration and Git's
   // repository-local environment when this test runs from pre-push. Isolate
@@ -26,6 +37,53 @@ function git(repo, ...args) {
   }).trim();
 }
 
+function createEntrypointFixture({
+  surface,
+  relativeFile,
+  extension,
+  maxLines,
+}) {
+  const repo = realpathSync(
+    mkdtempSync(path.join(tmpdir(), `file-size-${surface}-`)),
+  );
+  const scriptsDir = path.join(repo, "scripts");
+  const surfaceScriptsDir = path.join(repo, surface, "scripts");
+  mkdirSync(scriptsDir, { recursive: true });
+  mkdirSync(surfaceScriptsDir, { recursive: true });
+  copyFileSync(
+    path.join(repoRoot, "scripts/check-file-sizes-core.mjs"),
+    path.join(scriptsDir, "check-file-sizes-core.mjs"),
+  );
+  copyFileSync(
+    path.join(repoRoot, surface, "scripts/check-file-sizes.mjs"),
+    path.join(surfaceScriptsDir, "check-file-sizes.mjs"),
+  );
+  writeFileSync(
+    path.join(surfaceScriptsDir, "file-size-policy.mjs"),
+    `export const rules = [{ root: ${JSON.stringify(path.posix.dirname(relativeFile))}, extensions: new Set([${JSON.stringify(extension)}]), maxLines: ${maxLines} }];\n`,
+  );
+
+  git(repo, "init", "-b", "main");
+  git(repo, "config", "user.name", "Test");
+  git(repo, "config", "user.email", "test@example.com");
+  git(repo, "add", ".");
+  git(repo, "commit", "-m", "base");
+  const base = git(repo, "rev-parse", "HEAD");
+  git(repo, "switch", "-c", "feature");
+
+  const governedFile = path.join(repo, surface, relativeFile);
+  mkdirSync(path.dirname(governedFile), { recursive: true });
+  writeFileSync(governedFile, `${"line\n".repeat(maxLines)}line`);
+
+  const entrypointPath = path.join(surfaceScriptsDir, "check-file-sizes.mjs");
+  const result = spawnSync(realpathSync(process.execPath), [entrypointPath], {
+    cwd: repo,
+    encoding: "utf8",
+    env: { ...process.env, CHECK_FILE_SIZES_BASE: base },
+  });
+  return { result, relativeFile };
+}
+
 test("local base resolution uses the branch merge-base and fails without origin/main", () => {
   const repo = mkdtempSync(path.join(tmpdir(), "file-size-base-"));
   git(repo, "init", "-b", "main");
@@ -47,12 +105,107 @@ test("local base resolution uses the branch merge-base and fails without origin/
   );
 });
 
+test("surface entrypoints execute their exported policies", () => {
+  const cases = [
+    {
+      surface: "desktop",
+      relativeFile: "src-tauri/src/oversized.rs",
+      extension: ".rs",
+      maxLines: 1500,
+    },
+    {
+      surface: "mobile",
+      relativeFile: "lib/oversized.dart",
+      extension: ".dart",
+      maxLines: 1200,
+    },
+    {
+      surface: "web",
+      relativeFile: "src/app/oversized.ts",
+      extension: ".ts",
+      maxLines: 1000,
+    },
+  ];
+
+  for (const fixture of cases) {
+    const { result, relativeFile } = createEntrypointFixture(fixture);
+    assert.equal(
+      result.status,
+      1,
+      `${fixture.surface} should reject ceiling + 1: ${result.stderr || result.stdout}`,
+    );
+    assert.ok(result.stderr.includes(relativeFile), result.stderr);
+  }
+});
+
 test("counts empty, LF, and CRLF content with the existing semantics", () => {
   assert.equal(countLines(""), 0);
   assert.equal(countLines("one\n"), 2);
   assert.equal(countLines("one\r\ntwo"), 2);
 });
 
+test("surface entrypoints expose the exact ordered production policies", () => {
+  const policies = [
+    [
+      desktopPolicy,
+      [
+        ["src-tauri/src", [".rs"], 1500],
+        ["src-tauri/crates", [".rs"], 1500],
+        ["src/app", [".ts", ".tsx"], 1200],
+        ["src/features", [".ts", ".tsx"], 1200],
+        ["src/shared/api", [".ts", ".tsx"], 1200],
+        ["src/shared/context", [".ts", ".tsx"], 1200],
+        ["src/shared/lib", [".ts", ".tsx"], 1200],
+        ["src/shared/ui", [".ts", ".tsx"], 1200],
+        ["src/shared/styles", [".css"], 1200],
+      ],
+    ],
+    [mobilePolicy, [["lib", [".dart"], 1200]]],
+    [
+      webPolicy,
+      [
+        ["src/app", [".ts", ".tsx"], 1000],
+        ["src/features", [".ts", ".tsx"], 1000],
+        ["src/shared/api", [".ts", ".tsx"], 1000],
+      ],
+    ],
+  ];
+
+  for (const [policy, expectedRules] of policies) {
+    const actualRules = policy.rules.map((rule) => [
+      rule.root,
+      [...rule.extensions],
+      rule.maxLines,
+    ]);
+    assert.deepEqual(
+      actualRules,
+      expectedRules,
+      `${policy.label} production rules`,
+    );
+
+    for (const rule of policy.rules) {
+      assert.equal(
+        evaluateFileSize({
+          baseLines: null,
+          candidateLines: rule.maxLines,
+          maxLines: rule.maxLines,
+        }).violates,
+        false,
+        `${policy.label} ${rule.root} should allow the ceiling`,
+      );
+      assert.equal(
+        evaluateFileSize({
+          baseLines: null,
+          candidateLines: rule.maxLines + 1,
+          maxLines: rule.maxLines,
+        }).violates,
+        true,
+        `${policy.label} ${rule.root} should reject ceiling + 1`,
+      );
+    }
+  }
+});
+
 test("new files use the configured ceiling", () => {
   assert.equal(allowedLineCount(null, 1000), 1000);
   assert.deepEqual(