Support `bun` (#4916)

Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>

.github/workflows/main.yml

@@ -225,6 +225,36 @@ jobs:
           paths: "test-results/*.xml"
         if: always()
 
+  test-bun:
+    runs-on: ${{ matrix.os }}
+
+    needs: [build-core]
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download build artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: core-build-${{ runner.os }}
+          path: ./dist/
+
+      - uses: oven-sh/setup-bun@v1
+
+      - name: install test requirements
+        working-directory: src/test-bun
+        run: |
+          bun --version
+          bun install
+
+      - name: run bun tests
+        working-directory: src/test-bun
+        run: bun smoke-test.js
+
   test-deno:
     runs-on: ${{ matrix.os }}
 

src/js/compat.ts

@@ -262,6 +262,10 @@ export async function calculateDirname(): Promise<string> {
   }
   let fileName = ErrorStackParser.parse(err)[0].fileName!;
 
+  if (IN_NODE && !fileName.startsWith("file://")) {
+    fileName = `file://${fileName}`; // Error stack filenames are not starting with `file://` in `Bun`
+  }
+
   if (IN_NODE_ESM) {
     const nodePath = await import("node:path");
     const nodeUrl = await import("node:url");

src/js/environments.ts

@@ -5,8 +5,7 @@ export const IN_NODE =
   typeof process === "object" &&
   typeof process.versions === "object" &&
   typeof process.versions.node === "string" &&
-  typeof process.browser ===
-    "undefined"; /* This last condition checks if we run the browser shim of process */
+  !process.browser; /* This last condition checks if we run the browser shim of process */
 
 /** @private */
 export const IN_NODE_COMMONJS =
@@ -19,6 +18,9 @@ export const IN_NODE_COMMONJS =
 /** @private */
 export const IN_NODE_ESM = IN_NODE && !IN_NODE_COMMONJS;
 
+/** @private */
+export const IN_BUN = typeof globalThis.Bun !== "undefined";
+
 /** @private */
 export const IN_DENO = typeof Deno !== "undefined"; // just in case...
 
@@ -55,6 +57,7 @@ export function detectEnvironment(): Record<string, boolean> {
     IN_NODE: IN_NODE,
     IN_NODE_COMMONJS: IN_NODE_COMMONJS,
     IN_NODE_ESM: IN_NODE_ESM,
+    IN_BUN: IN_BUN,
     IN_DENO: IN_DENO,
     IN_BROWSER: IN_BROWSER,
     IN_BROWSER_MAIN_THREAD: IN_BROWSER_MAIN_THREAD,

src/test-bun/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "test-bun",
+  "module": "smoke-test.js",
+  "type": "module",
+  "scripts": {
+    "dev": "bun --watch smoke-test.js"
+  },
+  "devDependencies": {
+    "@types/bun": "latest"
+  },
+  "peerDependencies": {
+    "typescript": "^5.0.0"
+  },
+  "dependencies": {
+    "pyodide": "../../dist/"
+  }
+}

src/test-bun/smoke-test.js

@@ -0,0 +1,13 @@
+import { loadPyodide } from "pyodide";
+
+console.time("[load pyodide]");
+const pyodide = await loadPyodide();
+console.timeEnd("[load pyodide]");
+
+console.time("[run pyodide]");
+const result = await pyodide.runPythonAsync(`
+3+4
+`);
+console.timeEnd("[run pyodide]");
+
+console.log("result:", result.toString());