Migrate to ESMBundler and node 24 (#345)

.github/scripts/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    "target": "es2022",
+    "types": ["node"]
+  },
+  "include": ["check-all-tests-passed-needs.ts"]
+}

.github/workflows/test.yml

@@ -27,14 +27,15 @@ jobs:
         uses: zizmorcore/zizmor-action@71321a20a9ded102f6e9ce5718a2fcec2c4f70d8 # v0.5.2
       - uses: actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238 # v6.2.0
         with:
-          node-version: "20"
+          node-version-file: .nvmrc
+          cache: npm
       - run: |
           npm ci --ignore-scripts
       - run: |
           npm run all
       - name: Check all jobs are in all-tests-passed.needs
         run: |
-          tsc check-all-tests-passed-needs.ts
+          tsc -p tsconfig.json
           node check-all-tests-passed-needs.js
         working-directory: .github/scripts
       - name: Make sure no changes from linters are detected

.github/workflows/update-known-checksums.yml

@@ -16,11 +16,12 @@ jobs:
           persist-credentials: false
       - uses: actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238 # v6.2.0
         with:
-          node-version: "20"
+          node-version-file: .nvmrc
+          cache: npm
       - name: Update known checksums
         id: update-known-checksums
         run:
-          node dist/update-known-checksums/index.js
+          node dist/update-known-checksums/index.cjs
           src/download/checksum/known-checksums.ts ${{ secrets.GITHUB_TOKEN }}
       - run: npm ci --ignore-scripts && npm run all
       - name: Create Pull Request

.nvmrc

@@ -0,0 +1 @@
+24

__tests__/utils/pyproject-finder.test.ts

@@ -0,0 +1,122 @@
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
+
+const debug = jest.fn();
+const info = jest.fn();
+
+jest.unstable_mockModule("@actions/core", () => ({
+  debug,
+  info,
+}));
+
+const { findPyprojectToml } = await import("../../src/utils/pyproject-finder");
+
+const testFilePath = fileURLToPath(import.meta.url);
+const testDir = path.dirname(testFilePath);
+const repoRoot = path.resolve(testDir, "..", "..");
+const fixturesDir = path.join(repoRoot, "__tests__", "fixtures");
+
+describe("findPyprojectToml", () => {
+  beforeEach(() => {
+    debug.mockReset();
+    info.mockReset();
+  });
+
+  describe("when pyproject.toml exists in src directory", () => {
+    it("should return the exact path", () => {
+      const result = findPyprojectToml(fixturesDir, repoRoot);
+
+      expect(result).toContain("pyproject.toml");
+      expect(result).toContain("fixtures");
+      expect(info).toHaveBeenCalled();
+    });
+  });
+
+  describe("when pyproject.toml exists only in parent directory", () => {
+    it("should search upwards and find the parent's pyproject.toml", () => {
+      const subprojectDir = path.join(
+        fixturesDir,
+        "parent-config-project",
+        "subproject",
+      );
+
+      const result = findPyprojectToml(subprojectDir, repoRoot);
+
+      expect(result).toBeTruthy();
+      expect(result).toContain("pyproject.toml");
+      expect(result).toContain("parent-config-project");
+      expect(info).toHaveBeenCalled();
+    });
+  });
+
+  describe("boundary conditions", () => {
+    it("should stop searching at workspace root and return undefined when not found", () => {
+      const nodeModulesDir = path.join(repoRoot, "node_modules", "@actions");
+
+      const result = findPyprojectToml(nodeModulesDir, repoRoot);
+
+      expect(result).toBeUndefined();
+      expect(info).not.toHaveBeenCalledWith(
+        expect.stringContaining("Found pyproject.toml"),
+      );
+    });
+
+    it("should find pyproject.toml when it exists at workspace root", () => {
+      const parentConfigProjectDir = path.join(
+        fixturesDir,
+        "parent-config-project",
+      );
+      const subprojectDir = path.join(parentConfigProjectDir, "subproject");
+
+      const result = findPyprojectToml(subprojectDir, parentConfigProjectDir);
+
+      expect(result).toBeTruthy();
+      expect(result).toContain("pyproject.toml");
+      expect(result).toContain("parent-config-project");
+    });
+
+    it("should stop at workspace root even if searching from it", () => {
+      const result = findPyprojectToml(fixturesDir, fixturesDir);
+
+      expect(result).toBeTruthy();
+      expect(result).toContain("pyproject.toml");
+      expect(result).toContain("fixtures");
+    });
+  });
+
+  describe("edge cases", () => {
+    it("should handle relative paths", () => {
+      const result = findPyprojectToml("./__tests__/fixtures", ".");
+
+      expect(result).toBeTruthy();
+      expect(result).toContain("pyproject.toml");
+    });
+
+    it("should handle when src equals workspace root", () => {
+      const result = findPyprojectToml(fixturesDir, fixturesDir);
+
+      expect(result).toBeTruthy();
+      expect(result).toContain("pyproject.toml");
+      expect(result).toContain("fixtures");
+    });
+
+    it("should log debug messages for each checked path", () => {
+      const pythonProjectDir = path.join(fixturesDir, "python-project");
+
+      findPyprojectToml(pythonProjectDir, repoRoot);
+
+      expect(debug).toHaveBeenCalled();
+      expect(debug.mock.calls.length).toBeGreaterThan(0);
+      expect(debug.mock.calls[0][0]).toContain("Checking for");
+      expect(debug.mock.calls[0][0]).toContain("python-project");
+    });
+
+    it("should handle paths with trailing slashes", () => {
+      const result = findPyprojectToml(`${fixturesDir}/`, repoRoot);
+
+      expect(result).toBeTruthy();
+      expect(result).toContain("pyproject.toml");
+    });
+  });
+});

__tests__/utils/pyproject.test.ts

@@ -1,77 +1,82 @@
-import * as core from "@actions/core";
-import { findRuffVersionInSpec } from "./pyproject";
+import { beforeEach, describe, expect, it, jest } from "@jest/globals";
 
-jest.mock("@actions/core", () => ({
-  info: jest.fn(),
-  warning: jest.fn(),
+const info = jest.fn();
+const warning = jest.fn();
+
+jest.unstable_mockModule("@actions/core", () => ({
+  info,
+  warning,
 }));
 
+const { findRuffVersionInSpec } = await import("../../src/utils/pyproject");
+
 describe("findRuffVersionInSpec", () => {
   beforeEach(() => {
-    jest.clearAllMocks();
+    info.mockReset();
+    warning.mockReset();
   });
 
   describe("ruff dependency strings", () => {
     it("should extract version from 'ruff==0.9.3'", () => {
       const result = findRuffVersionInSpec("ruff==0.9.3");
       expect(result).toBe("0.9.3");
-      expect(core.info).toHaveBeenCalledWith(
+      expect(info).toHaveBeenCalledWith(
         "Found ruff version in requirements file: 0.9.3",
       );
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should extract version from 'ruff>=0.14'", () => {
       const result = findRuffVersionInSpec("ruff>=0.14");
       expect(result).toBe(">=0.14");
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should extract version from 'ruff ~=1.0.0'", () => {
       const result = findRuffVersionInSpec("ruff ~=1.0.0");
       expect(result).toBe("~=1.0.0");
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should extract version from 'ruff>=0.14,<1.0'", () => {
       const result = findRuffVersionInSpec("ruff>=0.14,<1.0");
       expect(result).toBe(">=0.14,<1.0");
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should extract version from 'ruff>=0.14,<2.0,!=1.5.0'", () => {
       const result = findRuffVersionInSpec("ruff>=0.14,<2.0,!=1.5.0");
       expect(result).toBe(">=0.14,<2.0,!=1.5.0");
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should return undefined for non-ruff dependency 'another-dep 0.1.6'", () => {
       const result = findRuffVersionInSpec("another-dep 0.1.6");
       expect(result).toBeUndefined();
-      expect(core.info).not.toHaveBeenCalled();
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(info).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should return undefined for non-ruff dependency 'another-dep==0.1.6'", () => {
       const result = findRuffVersionInSpec("another-dep==0.1.6");
       expect(result).toBeUndefined();
-      expect(core.info).not.toHaveBeenCalled();
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(info).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should strip trailing backslash", () => {
       const result = findRuffVersionInSpec("ruff==0.9.3 \\");
       expect(result).toBe("0.9.3");
-      expect(core.info).toHaveBeenCalledWith(
+      expect(info).toHaveBeenCalledWith(
         "Found ruff version in requirements file: 0.9.3",
       );
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should strip trailing backslash with whitespace", () => {
       const result = findRuffVersionInSpec("  ruff==0.9.3  \\  ");
       expect(result).toBe("0.9.3");
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
   });
 
@@ -81,10 +86,10 @@ describe("findRuffVersionInSpec", () => {
         'ruff>=0.14 ; python_version >= "3.11"',
       );
       expect(result).toBe(">=0.14");
-      expect(core.info).toHaveBeenCalledWith(
+      expect(info).toHaveBeenCalledWith(
         "Found ruff version in requirements file: >=0.14",
       );
-      expect(core.warning).toHaveBeenCalledWith(
+      expect(warning).toHaveBeenCalledWith(
         "Environment markers are ignored. ruff is a standalone tool that works independently of Python version.",
       );
     });
@@ -94,7 +99,7 @@ describe("findRuffVersionInSpec", () => {
         "ruff==0.9.3 ; sys_platform == 'linux'",
       );
       expect(result).toBe("0.9.3");
-      expect(core.warning).toHaveBeenCalledWith(
+      expect(warning).toHaveBeenCalledWith(
         "Environment markers are ignored. ruff is a standalone tool that works independently of Python version.",
       );
     });
@@ -104,7 +109,7 @@ describe("findRuffVersionInSpec", () => {
         'ruff>=0.14 ; python_version >= "3.11" and sys_platform == "linux"',
       );
       expect(result).toBe(">=0.14");
-      expect(core.warning).toHaveBeenCalledWith(
+      expect(warning).toHaveBeenCalledWith(
         "Environment markers are ignored. ruff is a standalone tool that works independently of Python version.",
       );
     });
@@ -114,7 +119,7 @@ describe("findRuffVersionInSpec", () => {
         'ruff>=0.14,<1.0 ; python_version >= "3.11"',
       );
       expect(result).toBe(">=0.14,<1.0");
-      expect(core.warning).toHaveBeenCalledWith(
+      expect(warning).toHaveBeenCalledWith(
         "Environment markers are ignored. ruff is a standalone tool that works independently of Python version.",
       );
     });
@@ -124,7 +129,7 @@ describe("findRuffVersionInSpec", () => {
     it("should handle whitespace", () => {
       const result = findRuffVersionInSpec("  ruff  >=0.14  ");
       expect(result).toBe(">=0.14");
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should handle whitespace with environment markers", () => {
@@ -132,28 +137,28 @@ describe("findRuffVersionInSpec", () => {
         "  ruff  >=0.14  ;  python_version >= '3.11'  ",
       );
       expect(result).toBe(">=0.14");
-      expect(core.warning).toHaveBeenCalled();
+      expect(warning).toHaveBeenCalled();
     });
 
     it("should return undefined for empty string", () => {
       const result = findRuffVersionInSpec("");
       expect(result).toBeUndefined();
-      expect(core.info).not.toHaveBeenCalled();
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(info).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should return undefined for whitespace only", () => {
       const result = findRuffVersionInSpec("   ");
       expect(result).toBeUndefined();
-      expect(core.info).not.toHaveBeenCalled();
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(info).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should return undefined for just semicolon", () => {
       const result = findRuffVersionInSpec(";");
       expect(result).toBeUndefined();
-      expect(core.info).not.toHaveBeenCalled();
-      expect(core.warning).not.toHaveBeenCalled();
+      expect(info).not.toHaveBeenCalled();
+      expect(warning).not.toHaveBeenCalled();
     });
 
     it("should handle exact example from issue #256", () => {
@@ -161,10 +166,10 @@ describe("findRuffVersionInSpec", () => {
         'ruff>=0.14 ; python_version >= "3.11"',
       );
       expect(result).toBe(">=0.14");
-      expect(core.info).toHaveBeenCalledWith(
+      expect(info).toHaveBeenCalledWith(
         "Found ruff version in requirements file: >=0.14",
       );
-      expect(core.warning).toHaveBeenCalledWith(
+      expect(warning).toHaveBeenCalledWith(
         "Environment markers are ignored. ruff is a standalone tool that works independently of Python version.",
       );
     });
@@ -174,7 +179,7 @@ describe("findRuffVersionInSpec", () => {
         "ruff>=0.14 ; python_version >= '3.11'",
       );
       expect(result).toBe(">=0.14");
-      expect(core.warning).toHaveBeenCalled();
+      expect(warning).toHaveBeenCalled();
     });
 
     it("should handle double-quoted environment markers", () => {
@@ -182,7 +187,7 @@ describe("findRuffVersionInSpec", () => {
         'ruff>=0.14 ; python_version >= "3.11"',
       );
       expect(result).toBe(">=0.14");
-      expect(core.warning).toHaveBeenCalled();
+      expect(warning).toHaveBeenCalled();
     });
   });
 });

action.yml

@@ -30,8 +30,8 @@ outputs:
   ruff-version:
     description: "The installed ruff version. Useful when using latest."
 runs:
-  using: "node20"
-  main: "dist/ruff-action/index.js"
+  using: "node24"
+  main: "dist/ruff-action/index.cjs"
 branding:
   icon: "code"
   color: "black"

biome.json

@@ -1,5 +1,5 @@
 {
-  "$schema": "https://biomejs.dev/schemas/2.3.2/schema.json",
+  "$schema": "https://biomejs.dev/schemas/2.4.9/schema.json",
   "assist": {
     "actions": {
       "source": {

jest.config.js

@@ -1,12 +0,0 @@
-/** @type {import('ts-jest').JestConfigWithTsJest} */
-module.exports = {
-  collectCoverageFrom: ["src/**/*.ts", "!src/**/*.d.ts"],
-  moduleFileExtensions: ["ts", "js"],
-  preset: "ts-jest",
-  roots: ["<rootDir>/src"],
-  testEnvironment: "node",
-  testMatch: ["**/*.test.ts"],
-  transform: {
-    "^.+\\.ts$": "ts-jest",
-  },
-};

jest.config.mjs

@@ -0,0 +1,12 @@
+import { createDefaultEsmPreset } from "ts-jest";
+
+const preset = createDefaultEsmPreset();
+
+/** @type {import('jest').Config} */
+export default {
+  ...preset,
+  collectCoverageFrom: ["src/**/*.ts", "!src/**/*.d.ts"],
+  moduleFileExtensions: ["ts", "js", "mjs"],
+  testEnvironment: "node",
+  testMatch: ["<rootDir>/__tests__/**/*.test.ts"],
+};

package.json

@@ -2,16 +2,18 @@
   "name": "ruff-action",
   "version": "1.0.0",
   "private": true,
+  "type": "module",
   "description": "A GitHub Action to run Ruff, an extremely fast Python linter and code formatter.",
-  "main": "dist/ruff-action/index.js",
+  "main": "dist/ruff-action/index.cjs",
   "scripts": {
-    "build": "tsc",
+    "build": "tsc --noEmit",
     "check": "biome check --write",
-    "package": "ncc build -o dist/ruff-action src/ruff-action.ts && ncc build -o dist/update-known-checksums src/update-known-checksums.ts",
+    "package": "node scripts/build-dist.mjs",
     "act": "act pull_request -W .github/workflows/test.yml --container-architecture linux/amd64 -s GITHUB_TOKEN=\"$(gh auth token)\"",
-    "update-known-checksums": "RUNNER_TEMP=known_checksums node dist/update-known-checksums/index.js src/download/checksum/known-checksums.ts \"$(gh auth token)\"",
-    "test": "jest",
-    "all": "npm ci --ignore-scripts && npm run build && npm run check && npm run test && npm run package"
+    "update-known-checksums": "RUNNER_TEMP=known_checksums node dist/update-known-checksums/index.cjs src/download/checksum/known-checksums.ts \"$(gh auth token)\"",
+    "test:unit": "node --experimental-vm-modules ./node_modules/jest/bin/jest.js",
+    "test": "npm run build && npm run test:unit",
+    "all": "npm run build && npm run check && npm run package && npm run test:unit"
   },
   "repository": {
     "type": "git",
@@ -26,9 +28,9 @@
   "author": "@eifinger",
   "license": "Apache-2.0",
   "dependencies": {
-    "@actions/core": "^1.11.1",
-    "@actions/exec": "^1.1.1",
-    "@actions/tool-cache": "^2.0.2",
+    "@actions/core": "^3.0.0",
+    "@actions/exec": "^3.0.0",
+    "@actions/tool-cache": "^4.0.0",
     "@octokit/core": "^7.0.3",
     "@octokit/plugin-paginate-rest": "^13.1.1",
     "@octokit/plugin-rest-endpoint-methods": "^16.0.0",
@@ -36,15 +38,15 @@
     "smol-toml": "^1.6.0"
   },
   "devDependencies": {
-    "@biomejs/biome": "2.3.2",
+    "@biomejs/biome": "^2.4.7",
     "@types/jest": "^29.5.14",
     "@types/js-yaml": "^4.0.9",
-    "@types/node": "^24.10.9",
+    "@types/node": "^25.5.0",
     "@types/semver": "^7.7.1",
-    "@vercel/ncc": "^0.38.3",
-    "jest": "^29.7.0",
-    "js-yaml": "^4.1.0",
-    "ts-jest": "^29.2.5",
-    "typescript": "^5.9.2"
+    "esbuild": "^0.27.4",
+    "jest": "^30.3.0",
+    "js-yaml": "^4.1.1",
+    "ts-jest": "^29.4.6",
+    "typescript": "^5.9.3"
   }
 }

scripts/build-dist.mjs

@@ -0,0 +1,41 @@
+import { mkdir, rm } from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { build } from "esbuild";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const repoRoot = path.resolve(__dirname, "..");
+
+const builds = [
+  {
+    entryPoint: path.join(repoRoot, "src", "ruff-action.ts"),
+    outfile: path.join(repoRoot, "dist", "ruff-action", "index.cjs"),
+    staleOutfile: path.join(repoRoot, "dist", "ruff-action", "index.js"),
+  },
+  {
+    entryPoint: path.join(repoRoot, "src", "update-known-checksums.ts"),
+    outfile: path.join(repoRoot, "dist", "update-known-checksums", "index.cjs"),
+    staleOutfile: path.join(
+      repoRoot,
+      "dist",
+      "update-known-checksums",
+      "index.js",
+    ),
+  },
+];
+
+await Promise.all(
+  builds.map(async ({ entryPoint, outfile, staleOutfile }) => {
+    await rm(staleOutfile, { force: true });
+    await mkdir(path.dirname(outfile), { recursive: true });
+    await build({
+      bundle: true,
+      entryPoints: [entryPoint],
+      format: "cjs",
+      outfile,
+      platform: "node",
+      target: "node24",
+    });
+  }),
+);

src/ruff-action.ts

@@ -136,16 +136,17 @@ function setOutputFormat() {
 }
 
 function addMatchers(): void {
-  const matchersPath = path.join(
-    __dirname,
-    `..${path.sep}..`,
-    ".github",
-    "matchers",
-  );
+  const actionRoot = getActionRoot();
+  const matchersPath = path.join(actionRoot, ".github", "matchers");
   core.info(`##[add-matcher]${path.join(matchersPath, "check.json")}`);
   core.info(`##[add-matcher]${path.join(matchersPath, "format.json")}`);
 }
 
+function getActionRoot(): string {
+  const entrypoint = process.argv[1] ?? process.cwd();
+  return path.resolve(path.dirname(entrypoint), "..", "..");
+}
+
 async function runRuff(
   ruffExecutablePath: string,
   args: string[],

src/update-known-checksums.ts

@@ -10,9 +10,9 @@ const PaginatingOctokit = Octokit.plugin(paginateRest, restEndpointMethods);
 
 async function run(): Promise<void> {
   const checksumFilePath = process.argv.slice(2)[0];
-  const github_token = process.argv.slice(2)[1];
+  const githubToken = process.argv.slice(2)[1];
 
-  const octokit = new PaginatingOctokit({ auth: github_token });
+  const octokit = new PaginatingOctokit({ auth: githubToken });
 
   const response = await octokit.paginate(octokit.rest.repos.listReleases, {
     owner: OWNER,

src/utils/pyproject-finder.test.ts

@@ -1,183 +0,0 @@
-import * as path from "node:path";
-import * as core from "@actions/core";
-import { findPyprojectToml } from "./pyproject-finder";
-
-jest.mock("@actions/core", () => ({
-  debug: jest.fn(),
-  info: jest.fn(),
-}));
-
-describe("findPyprojectToml", () => {
-  beforeEach(() => {
-    jest.clearAllMocks();
-  });
-
-  describe("when pyproject.toml exists in src directory", () => {
-    it("should return the exact path", () => {
-      const fixturesDir = path.join(
-        __dirname,
-        "..",
-        "..",
-        "__tests__",
-        "fixtures",
-      );
-      const workspaceRoot = path.join(__dirname, "..", "..");
-
-      const result = findPyprojectToml(fixturesDir, workspaceRoot);
-
-      expect(result).toContain("pyproject.toml");
-      expect(result).toContain("fixtures");
-      expect(core.info).toHaveBeenCalled();
-    });
-  });
-
-  describe("when pyproject.toml exists only in parent directory", () => {
-    it("should search upwards and find the parent's pyproject.toml", () => {
-      // subproject doesn't have a pyproject.toml, but its parent (parent-config-project) does
-      const subprojectDir = path.join(
-        __dirname,
-        "..",
-        "..",
-        "__tests__",
-        "fixtures",
-        "parent-config-project",
-        "subproject",
-      );
-      const workspaceRoot = path.join(__dirname, "..", "..");
-
-      const result = findPyprojectToml(subprojectDir, workspaceRoot);
-
-      expect(result).toBeTruthy();
-      expect(result).toContain("pyproject.toml");
-      expect(result).toContain("parent-config-project");
-      expect(core.info).toHaveBeenCalled();
-    });
-  });
-
-  describe("boundary conditions", () => {
-    it("should stop searching at workspace root and return undefined when not found", () => {
-      // Create a path that won't have pyproject.toml above it
-      const nodeModulesDir = path.join(
-        __dirname,
-        "..",
-        "..",
-        "node_modules",
-        "@actions",
-      );
-      const workspaceRoot = path.join(__dirname, "..", "..");
-
-      const result = findPyprojectToml(nodeModulesDir, workspaceRoot);
-
-      // Should return undefined since there's no pyproject.toml in the search path
-      expect(result).toBeUndefined();
-      expect(core.info).not.toHaveBeenCalledWith(
-        expect.stringContaining("Found pyproject.toml"),
-      );
-    });
-
-    it("should find pyproject.toml when it exists at workspace root", () => {
-      // Use parent-config-project as the "workspace root" for this test
-      // Start from subproject (which has no pyproject.toml) to search up to workspace root
-      const subprojectDir = path.join(
-        __dirname,
-        "..",
-        "..",
-        "__tests__",
-        "fixtures",
-        "parent-config-project",
-        "subproject",
-      );
-      const workspaceRoot = path.join(
-        __dirname,
-        "..",
-        "..",
-        "__tests__",
-        "fixtures",
-        "parent-config-project",
-      );
-
-      const result = findPyprojectToml(subprojectDir, workspaceRoot);
-
-      expect(result).toBeTruthy();
-      expect(result).toContain("pyproject.toml");
-      expect(result).toContain("parent-config-project");
-    });
-
-    it("should stop at workspace root even if searching from it", () => {
-      const workspaceRoot = path.join(
-        __dirname,
-        "..",
-        "..",
-        "__tests__",
-        "fixtures",
-      );
-
-      const result = findPyprojectToml(workspaceRoot, workspaceRoot);
-
-      // Should find pyproject.toml at workspace root
-      expect(result).toBeTruthy();
-      expect(result).toContain("pyproject.toml");
-      expect(result).toContain("fixtures");
-    });
-  });
-
-  describe("edge cases", () => {
-    it("should handle relative paths", () => {
-      const srcDir = "./__tests__/fixtures";
-      const workspaceRoot = ".";
-
-      const result = findPyprojectToml(srcDir, workspaceRoot);
-
-      // Should work with relative paths
-      expect(result).toBeTruthy();
-      expect(result).toContain("pyproject.toml");
-    });
-
-    it("should handle when src equals workspace root", () => {
-      const workspaceRoot = path.join(
-        __dirname,
-        "..",
-        "..",
-        "__tests__",
-        "fixtures",
-      );
-      const result = findPyprojectToml(workspaceRoot, workspaceRoot);
-
-      expect(result).toBeTruthy();
-      expect(result).toContain("pyproject.toml");
-      expect(result).toContain("fixtures");
-    });
-
-    it("should log debug messages for each checked path", () => {
-      const pythonProjectDir = path.join(
-        __dirname,
-        "..",
-        "..",
-        "__tests__",
-        "fixtures",
-        "python-project",
-      );
-      const workspaceRoot = path.join(__dirname, "..", "..");
-
-      findPyprojectToml(pythonProjectDir, workspaceRoot);
-
-      expect(core.debug).toHaveBeenCalled();
-      const debugCalls = (core.debug as jest.Mock).mock.calls;
-      expect(debugCalls.length).toBeGreaterThan(0);
-
-      // First debug call should be for the starting directory
-      expect(debugCalls[0][0]).toContain("Checking for");
-      expect(debugCalls[0][0]).toContain("python-project");
-    });
-
-    it("should handle paths with trailing slashes", () => {
-      const fixturesDir = `${path.join(__dirname, "..", "..", "__tests__", "fixtures")}/`;
-      const workspaceRoot = path.join(__dirname, "..", "..");
-
-      const result = findPyprojectToml(fixturesDir, workspaceRoot);
-
-      expect(result).toBeTruthy();
-      expect(result).toContain("pyproject.toml");
-    });
-  });
-});

src/utils/pyproject-finder.ts

@@ -26,30 +26,20 @@ export function findPyprojectToml(
       core.info(`Found pyproject.toml at ${pyprojectPath}`);
       return pyprojectPath;
     }
-
-    // Check if we've reached the workspace root
     if (currentDir === resolvedWorkspaceRoot) {
-      // If we're at workspace root and didn't find it, stop searching
-      break;
+      return undefined;
     }
 
-    // Move up to parent directory
     const parentDir = path.dirname(currentDir);
-
-    // If parent is the same as current, we've reached the filesystem root
-    if (parentDir === currentDir) {
-      break;
+    if (
+      parentDir === currentDir ||
+      !isPathWithinWorkspace(parentDir, resolvedWorkspaceRoot)
+    ) {
+      return undefined;
     }
 
     currentDir = parentDir;
-
-    // If we've gone past the workspace root, stop searching
-    if (isPathWithinWorkspace(currentDir, resolvedWorkspaceRoot) === false) {
-      break;
-    }
   }
-
-  return undefined;
 }
 
 /**
@@ -62,18 +52,7 @@ export function findPyprojectToml(
 function isPathWithinWorkspace(
   checkPath: string,
   workspaceRoot: string,
-): boolean | undefined {
-  try {
-    const checkPathResolved = path.resolve(checkPath);
-    const workspaceRootResolved = path.resolve(workspaceRoot);
-
-    // Check if checkPath starts with workspaceRoot (case-insensitive on Windows)
-    const relativePath = path.relative(
-      workspaceRootResolved,
-      checkPathResolved,
-    );
-    return !relativePath.startsWith("..") && !path.isAbsolute(relativePath);
-  } catch {
-    return undefined;
-  }
+): boolean {
+  const relativePath = path.relative(workspaceRoot, checkPath);
+  return !relativePath.startsWith("..") && !path.isAbsolute(relativePath);
 }

tsconfig.json

@@ -1,12 +1,12 @@
 {
   "compilerOptions": {
-    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
-    "module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
-    "noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,
-    "outDir": "./lib" /* Redirect output structure to the directory. */,
-    "rootDir": "./src" /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */,
-    "strict": true /* Enable all strict type-checking options. */,
-    "target": "ES2022" /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
+    "esModuleInterop": true,
+    "isolatedModules": true,
+    "module": "esnext",
+    "moduleResolution": "bundler",
+    "noImplicitAny": true,
+    "strict": true,
+    "target": "ES2022"
   },
-  "exclude": ["node_modules", "**/*.test.ts"]
+  "include": ["src/**/*.ts"]
 }