chore: replace jest with bun test runner (#452)

* chore: replace jest with bun test runner

* fix build

Author: danadajian

CONTRIBUTING.md

@@ -20,7 +20,7 @@ where "my-new-feature" describes what you're working on.
 
 ### 3. Add tests for any bug fixes or new functionality
 
-All functions must be tested with a unit test. Please follow the existing convention of one exported function per file with a corresponding file to test it. Run tests using `yarn test`, or using the [Jest CLI](https://jestjs.io/docs/cli).
+All functions must be tested with a unit test. Please follow the existing convention of one exported function per file with a corresponding file to test it. Run tests using `bun test`.
 
 There is also an integration test present in the [test workflow](./.github/workflows/test.yaml), which will actually run this Github Action using the code from this repository. This allows you to test your change to the Github Action right within the pull request you make.
 

bun.lock

@@ -22,7 +22,6 @@ module.exports = [
       "@typescript-eslint/no-namespace": "off",
       "@typescript-eslint/no-non-null-assertion": "error",
       "@typescript-eslint/no-unsafe-argument": "error",
-      "@typescript-eslint/no-unsafe-call": "error",
     },
   },
   {

eslint.config.js

@@ -30,14 +30,13 @@
     "cypress": ">=13"
   },
   "devDependencies": {
-    "@swc/jest": "0.2.39",
     "@total-typescript/ts-reset": "0.6.1",
+    "@types/babel__generator": "7.27.0",
+    "@types/bun": "1.3.1",
     "@types/react": "19.2.2",
-    "@types/jest": "30.0.0",
     "@types/node": "24.9.2",
     "cypress": "15.5.0",
     "husky": "9.1.7",
-    "jest": "30.2.0",
     "eslint": "9.39.0",
     "eslint-plugin-cypress": "5.2.0",
     "react": "19.2.0",
@@ -57,20 +56,6 @@
     "lint": "eslint .",
     "prepack": "bun run build",
     "prepare": "husky",
-    "test": "NODE_OPTIONS=--experimental-vm-modules jest"
-  },
-  "jest": {
-    "transform": {
-      "^.+\\.(t|j)sx?$": [
-        "@swc/jest",
-        {
-          "jsc": {
-            "target": "esnext"
-          }
-        }
-      ]
-    },
-    "testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
-    "clearMocks": true
+    "test": "bun test"
   }
 }

package.json

@@ -12,7 +12,7 @@ limitations under the License.
 */
 
 import { generateContentWithExports } from "../src/generate-content-with-exports";
-import { expect } from "@jest/globals";
+import { describe, expect, it } from "bun:test";
 
 const filePaths = [
   "cypress/commands/file/path/1.tsx",

test/generate-content-with-exports.test.ts

@@ -11,11 +11,13 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { readFileSync } from "fs";
 import { generateContentWithImports } from "../src/generate-content-with-imports";
+import { describe, expect, it, mock } from "bun:test";
 
-jest.mock("fs");
-import { expect } from "@jest/globals";
+const readFileSyncMock = mock();
+mock.module("fs", () => ({
+  readFileSync: readFileSyncMock,
+}));
 
 const filePath = "filePath";
 const prettierConfig = {
@@ -25,7 +27,7 @@ const prettierConfig = {
 
 describe("generateContentWithImports", () => {
   it("should generate types when types do not exist", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`// some comment
+    readFileSyncMock.mockReturnValue(`// some comment
 
 import { mount } from 'cypress/react18';
 
@@ -68,7 +70,7 @@ import('../commands').then(Cypress.Commands.addAll);
   });
 
   it("should do nothing when types exist", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`// some comment
+    readFileSyncMock.mockReturnValue(`// some comment
 
 import { mount } from 'cypress/react18';
 

test/generate-content-with-imports.test.ts

@@ -12,10 +12,12 @@ limitations under the License.
 */
 
 import { generateContentsWithInterface } from "../src/generate-contents-with-interface";
-import { readFileSync } from "fs";
-import { expect } from "@jest/globals";
+import { describe, expect, it, mock } from "bun:test";
 
-jest.mock("fs");
+const readFileSyncMock = mock();
+mock.module("fs", () => ({
+  readFileSync: readFileSyncMock,
+}));
 
 const filePath = "filePath";
 const prettierConfig = {
@@ -25,7 +27,7 @@ const prettierConfig = {
 
 describe("generateContentsWithInterface", () => {
   it("should generate types when types do not exist", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`// some comment
+    readFileSyncMock.mockReturnValue(`// some comment
 
 export function functionExampleOneInput(input1: string) {
   cy.log('Here is a custom command!');
@@ -89,7 +91,7 @@ declare global {
   });
 
   it("should generate types when types exist", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`// some comment
+    readFileSyncMock.mockReturnValue(`// some comment
 
 export function functionExampleOneInput(input1: string) {
   cy.log('Here is a custom command!');
@@ -163,7 +165,7 @@ declare global {
   });
 
   it("should preserve formatting", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`// some comment
+    readFileSyncMock.mockReturnValue(`// some comment
 
 export function functionExampleOneInput(input1: string) {
   cy.log('Here is a custom command!')
@@ -231,7 +233,7 @@ declare global {
   });
 
   it("should handle generic types properly", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`// some comment
+    readFileSyncMock.mockReturnValue(`// some comment
 
 export function functionExampleGenericType(input1: string) {
   cy.log<GenericType>('Here is a generic type!');
@@ -259,7 +261,7 @@ declare global {
   });
 
   it("should throw error for object-destructured input", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`
+    readFileSyncMock.mockReturnValue(`
 export const objectDestructureExample = ({ input1, input2 }: { input1: string; input2: string }) => {
   cy.log(input1);
   cy.log(input2);
@@ -271,7 +273,7 @@ export const objectDestructureExample = ({ input1, input2 }: { input1: string; i
   });
 
   it("should handle file with only exports", async () => {
-    (readFileSync as jest.Mock).mockReturnValue(`export * from './some-file';
+    readFileSyncMock.mockReturnValue(`export * from './some-file';
 export * from './some-other-file';
 `);
     const result = await generateContentsWithInterface(

test/generate-contents-with-interface.test.ts

@@ -6,7 +6,7 @@
     "lib": ["ESNext", "DOM"],
     "jsx": "react",
     "skipLibCheck": true,
-    "types": ["cypress", "jest"],
+    "types": ["bun", "cypress"],
     "noEmit": true,
     "noImplicitAny": true,
     "noUncheckedIndexedAccess": true,