fix(deps): migrate off jest/ts-jest to vitest

package.json

@@ -8,7 +8,7 @@
     "build": "tsc && ncc build lib/main.js && sed -i 's/\\x0D$//' ./dist/index.js",
     "format": "prettier --write \"**/*.ts\"",
     "format-check": "prettier --check \"**/*.ts\"",
-    "test": "NODE_OPTIONS='--experimental-vm-modules' jest",
+    "test": "vitest run",
     "readme": "npx action-docs -u && prettier --write README.md"
   },
   "repository": {
@@ -26,15 +26,13 @@
     "shellwords-ts": "^3.0.1"
   },
   "devDependencies": {
-    "@types/jest": "^30.0.0",
     "@types/js-yaml": "^4.0.9",
     "@types/node": "^24.13.3",
     "@vercel/ncc": "^0.44.1",
     "action-docs": "^2.5.1",
-    "jest": "^30.4.2",
     "prettier": "^3.9.6",
-    "ts-jest": "^29.4.12",
     "ts-node": "^10.9.2",
-    "typescript": "^7.0.2"
+    "typescript": "^7.0.2",
+    "vitest": "^4.1.10"
   }
 }

src/dirty-files.test.ts

@@ -1,4 +1,4 @@
-import { jest } from "@jest/globals";
+import { describe, expect, test } from "vitest";
 
 import { parseGitStatus, isInterestingFile } from "./dirty-files.js";
 

src/envsubst.test.ts

@@ -1,4 +1,4 @@
-import { jest } from "@jest/globals";
+import { describe, expect, test } from "vitest";
 
 import { envsubst } from "./envsubst.js";
 

src/get-cache-keys.test.ts

@@ -1,4 +1,4 @@
-import { jest } from "@jest/globals";
+import { expect, test } from "vitest";
 
 import { getCacheKeys } from "./get-cache-keys.js";
 

src/parse-stack-path.test.ts

@@ -1,4 +1,4 @@
-import { jest } from "@jest/globals";
+import { expect, test } from "vitest";
 
 import { parseStackPath } from "./parse-stack-path.js";
 

src/parse-stack-query.test.ts

@@ -1,4 +1,4 @@
-import { jest } from "@jest/globals";
+import { expect, test } from "vitest";
 
 import { parseStackQuery } from "./parse-stack-query.js";
 

src/stack-cli.test.ts

@@ -1,10 +1,10 @@
 import { ExecOptions } from "@actions/exec";
-import { jest } from "@jest/globals";
+import { describe, expect, test, vi } from "vitest";
 
 import { ExecDelegate, StackCLI } from "./stack-cli.js";
 
 const exec: ExecDelegate = {
-  exec: jest.fn((command: string, args: string[], options?: ExecOptions) =>
+  exec: vi.fn((command: string, args: string[], options?: ExecOptions) =>
     Promise.resolve(0),
   ),
 };

src/stack-yaml.test.ts

@@ -1,4 +1,4 @@
-import { jest } from "@jest/globals";
+import { describe, expect, test, vi } from "vitest";
 
 import { parseStackYaml, getStackDirectories } from "./stack-yaml.js";
 import { StackCLI } from "./stack-cli.js";
@@ -13,9 +13,8 @@ programs: ${testPrograms}
 function mockStackCLI(): StackCLI {
   const stack = new StackCLI([]);
 
-  jest
-    .spyOn(stack, "read")
-    .mockImplementation((args: string[]): Promise<string> => {
+  vi.spyOn(stack, "read").mockImplementation(
+    (args: string[]): Promise<string> => {
       // Stringify to avoid array-comparison pitfalls
       const expected = ["path", "--stack-root", "--programs"].toString();
       const given = args.toString();
@@ -27,7 +26,8 @@ function mockStackCLI(): StackCLI {
       }
 
       return Promise.resolve(testStackPathYaml);
-    });
+    },
+  );
 
   return stack;
 }

src/with-cache.test.ts

@@ -1,5 +1,5 @@
 import * as core from "@actions/core";
-import { jest } from "@jest/globals";
+import { expect, test, vi } from "vitest";
 
 import { getCacheKeys } from "./get-cache-keys.js";
 import {
@@ -9,11 +9,11 @@ import {
 } from "./with-cache.js";
 
 const cache: CacheDelegate = {
-  restoreCache: jest.fn(() => Promise.resolve("")),
-  saveCache: jest.fn(() => Promise.resolve(0)),
+  restoreCache: vi.fn(() => Promise.resolve("")),
+  saveCache: vi.fn(() => Promise.resolve(0)),
 };
 
-const restoreCacheMock = jest.spyOn(cache, "restoreCache");
+const restoreCacheMock = vi.spyOn(cache, "restoreCache");
 
 async function testFunction(): Promise<number> {
   return 42;

vitest.config.ts

@@ -0,0 +1,8 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    environment: "node",
+    mockReset: true,
+  },
+});