feat: experimental native bun support

.github/workflows/ci.yml

@@ -25,10 +25,16 @@ jobs:
         with:
           node-version: ${{ matrix.node }}
           cache: "pnpm"
+      - uses: oven-sh/setup-bun@v1
+        if: ${{ matrix.os != 'windows-latest' }}
+        with:
+          bun-version: latest
       - run: pnpm install
       - run: pnpm lint
+        if: ${{ matrix.os != 'windows-latest' }}
       - run: pnpm build
-      - run: pnpm test
-
+      - run: pnpm vitest run --coverage
+      - run: pnpm test:bun --coverage
+        if: ${{ matrix.os != 'windows-latest' }}
       # - name: Coverage
       #   uses: codecov/codecov-action@v1

.gitignore

@@ -3,3 +3,4 @@ node_modules
 dist
 *.log*
 coverage
+.tmp

README.md

@@ -129,6 +129,14 @@ List of modules (within `node_modules`) to always use native require for them.
 
 List of modules (within `node_modules`) to transform them regardless of syntax.
 
+### `experimentalBun`
+
+- Type: Boolean
+- Default: Enabled if `process.versions.bun` exists (Bun runtime)
+- Environment Variable: `JITI_EXPERIMENTAL_BUN`
+
+Enable experimental native Bun support for transformations.
+
 ## Development
 
 - Clone this repository

package.json

@@ -21,7 +21,8 @@
     "lint": "eslint --ext .ts,.js . && prettier -c src lib test stubs",
     "lint:fix": "eslint --fix --ext .ts,.js . && prettier -w src lib test stubs",
     "release": "pnpm build && pnpm test && changelogen --release --push && npm publish",
-    "test": "pnpm lint && vitest run --coverage"
+    "test": "pnpm lint && vitest run --coverage && pnpm test:bun",
+    "test:bun": "bun --bun test test/bun"
   },
   "devDependencies": {
     "@babel/core": "^7.22.15",

src/jiti.ts

@@ -33,6 +33,7 @@ const _EnvSourceMaps = destr<boolean>(process.env.JITI_SOURCE_MAPS);
 const _EnvAlias = destr<Record<string, string>>(process.env.JITI_ALIAS);
 const _EnvTransform = destr<string[]>(process.env.JITI_TRANSFORM_MODULES);
 const _EnvNative = destr<string[]>(process.env.JITI_NATIVE_MODULES);
+const _ExpBun = destr<string[]>(process.env.JITI_EXPERIMENTAL_BUN);
 
 const isWindows = platform() === "win32";
 
@@ -49,6 +50,7 @@ const defaults: JITIOptions = {
   alias: _EnvAlias,
   nativeModules: _EnvNative || [],
   transformModules: _EnvTransform || [],
+  experimentalBun: _ExpBun === undefined ? !!process.versions.bun : !!_ExpBun,
 };
 
 type Require = typeof require;
@@ -292,6 +294,20 @@ export default function createJITI(
       return nativeRequire(id);
     }
 
+    // Experimental Bun support
+    if (opts.experimentalBun && !opts.transformOptions) {
+      try {
+        debug(`[bun] [native] ${id}`);
+        const _mod = nativeRequire(id);
+        if (opts.requireCache === false) {
+          delete nativeRequire.cache[id];
+        }
+        return _interopDefault(_mod);
+      } catch (error: any) {
+        debug(`[bun] Using fallback for ${id} because of an error:`, error);
+      }
+    }
+
     // Resolve path
     const filename = _resolve(id);
     const ext = extname(filename);

src/types.ts

@@ -29,4 +29,5 @@ export type JITIOptions = {
   alias?: Record<string, string>;
   nativeModules?: string[];
   transformModules?: string[];
+  experimentalBun?: boolean;
 };

test/bun.test.ts

@@ -0,0 +1,42 @@
+import { fileURLToPath } from "node:url";
+import { readdir, writeFile, mkdir } from "node:fs/promises";
+import { join } from "node:path";
+// @ts-ignore
+import { test, expect } from "bun:test";
+
+import jiti from "../lib/index.js";
+
+const fixturesDir = fileURLToPath(new URL("fixtures", import.meta.url));
+
+const fixtures = await readdir(fixturesDir);
+
+const _jiti = jiti(fixturesDir, {
+  debug: true,
+  interopDefault: true,
+  requireCache: false,
+  cache: false,
+});
+
+for (const fixture of fixtures) {
+  if (fixture.startsWith("error-")) {
+    continue;
+  }
+  test("fixtures/" + fixture, () => {
+    _jiti("./" + fixture);
+  });
+}
+
+test("hmr", async () => {
+  await mkdir(join(fixturesDir, "../.tmp"), { recursive: true });
+  const tmpFile = join(fixturesDir, "../.tmp/bun.mjs");
+
+  let value;
+
+  await writeFile(tmpFile, "export default 1");
+  value = _jiti(tmpFile);
+  expect(value).toBe(1);
+
+  await writeFile(tmpFile, "export default 2");
+  value = _jiti(tmpFile);
+  expect(value).toBe(2);
+});

vitest.config.ts

@@ -2,6 +2,10 @@ import { defineConfig } from "vitest/config";
 
 export default defineConfig({
   test: {
-    exclude: ["**/test.{ts,mjs,cjs,js}", "node_modules/**/*"],
+    exclude: [
+      "**/test.{ts,mjs,cjs,js}",
+      "node_modules/**/*",
+      "test/bun.test.ts",
+    ],
   },
 });