1 files changed, 227 insertions, 0 deletions
diff --git a/test/bun.js/preload-test.test.js b/test/bun.js/preload-test.test.js
new file mode 100644
index 000000000..76603b3a0
--- /dev/null
+++ b/test/bun.js/preload-test.test.js
@@ -0,0 +1,227 @@
+import { spawnSync } from "bun";
+import { describe, expect, test } from "bun:test";
+import { mkdirSync, realpathSync } from "fs";
+import { tmpdir } from "os";
+import { join } from "path";
+import { bunEnv } from "./bunEnv";
+import { bunExe } from "./bunExe";
+const preloadModule = `
+import {plugin} from 'bun';
+
+plugin({
+    setup(build) {
+        build.onResolve({ filter: /.*\.txt$/, }, async (args) => {
+            return {
+                path: args.path,
+                namespace: 'boop'
+            }
+        });
+    build.onResolve({ namespace: "boop", filter: /.*/ }, async (args) => {
+            return {
+                path: args.path,
+                namespace: 'boop'
+            }
+        });
+    build.onLoad({ namespace: "boop", filter: /.*/ }, async (args) => {
+            return {
+                contents: '"hello world"',
+                loader: 'json'
+            }
+        });
+    }
+});
+    `;
+
+const mainModule = `
+    import hey from './hey.txt';
+
+    if (hey !== 'hello world') {
+        throw new Error('preload test failed');
+    }
+
+    console.log('Test passed');
+    process.exit(0);
+`;
+
+const bunfig = `preload = ["./preload.js"]`;
+
+describe("preload", () => {
+  test("works", async () => {
+    const preloadDir = join(realpathSync(tmpdir()), "bun-preload-test");
+    mkdirSync(preloadDir, { recursive: true });
+    const preloadPath = join(preloadDir, "preload.js");
+    const mainPath = join(preloadDir, "main.js");
+    const bunfigPath = join(preloadDir, "bunfig.toml");
+    await Bun.write(preloadPath, preloadModule);
+    await Bun.write(mainPath, mainModule);
+    await Bun.write(bunfigPath, bunfig);
+
+    const cmds = [
+      [bunExe(), "run", mainPath],
+      [bunExe(), mainPath],
+    ];
+
+    for (let cmd of cmds) {
+      const { stderr, exitCode, stdout } = spawnSync({
+        cmd,
+        cwd: preloadDir,
+        stderr: "pipe",
+        stdout: "pipe",
+        env: bunEnv,
+      });
+
+      expect(exitCode).toBe(0);
+      expect(stderr.toString()).toBe("");
+      expect(stdout.toString()).toContain("Test passed");
+    }
+  });
+
+  test("works from CLI", async () => {
+    const preloadDir = join(realpathSync(tmpdir()), "bun-preload-test4");
+    mkdirSync(preloadDir, { recursive: true });
+    const preloadPath = join(preloadDir, "preload.js");
+    const mainPath = join(preloadDir, "main.js");
+    await Bun.write(preloadPath, preloadModule);
+    await Bun.write(mainPath, mainModule);
+
+    const cmds = [
+      [bunExe(), "-r=" + preloadPath, "run", mainPath],
+      [bunExe(), "-r=" + preloadPath, mainPath],
+    ];
+
+    for (let cmd of cmds) {
+      const { stderr, exitCode, stdout } = spawnSync({
+        cmd,
+        cwd: preloadDir,
+        stderr: "pipe",
+        stdout: "pipe",
+        env: bunEnv,
+      });
+
+      expect(exitCode).toBe(0);
+      expect(stderr.toString()).toBe("");
+      expect(stdout.toString()).toContain("Test passed");
+    }
+  });
+
+  describe("as entry point", () => {
+    const preloadModule = `
+import {plugin} from 'bun';
+
+plugin({
+    setup(build) {
+        build.onResolve({ filter: /.*\.txt$/, }, async (args) => {
+            return {
+                path: args.path,
+                namespace: 'boop'
+            }
+        });
+    build.onResolve({ namespace: "boop", filter: /.*/ }, async (args) => {
+            return {
+                path: args.path,
+                namespace: 'boop'
+            }
+        });
+    build.onLoad({ namespace: "boop", filter: /.*/ }, async (args) => {
+            return {
+                contents: 'console.log("Test passed")',
+                loader: 'js'
+            }
+        });
+    }
+});
+    `;
+
+    test("works from CLI", async () => {
+      const preloadDir = join(realpathSync(tmpdir()), "bun-preload-test6");
+      mkdirSync(preloadDir, { recursive: true });
+      const preloadPath = join(preloadDir, "preload.js");
+      const mainPath = join(preloadDir, "boop.txt");
+      await Bun.write(preloadPath, preloadModule);
+      await Bun.write(mainPath, "beep");
+
+      const cmds = [
+        [bunExe(), "-r=" + preloadPath, "run", mainPath],
+        [bunExe(), "-r=" + preloadPath, mainPath],
+      ];
+
+      for (let cmd of cmds) {
+        const { stderr, exitCode, stdout } = spawnSync({
+          cmd,
+          cwd: preloadDir,
+          stderr: "pipe",
+          stdout: "pipe",
+          env: bunEnv,
+        });
+
+        expect(stderr.toString()).toBe("");
+        expect(stdout.toString()).toContain("Test passed");
+        expect(exitCode).toBe(0);
+      }
+    });
+  });
+
+  test("throws an error when preloaded module fails to execute", async () => {
+    const preloadModule = "throw new Error('preload test failed');";
+
+    const preloadDir = join(realpathSync(tmpdir()), "bun-preload-test3");
+    mkdirSync(preloadDir, { recursive: true });
+    const preloadPath = join(preloadDir, "preload.js");
+    const mainPath = join(preloadDir, "main.js");
+    const bunfigPath = join(preloadDir, "bunfig.toml");
+    await Bun.write(preloadPath, preloadModule);
+    await Bun.write(mainPath, mainModule);
+    await Bun.write(bunfigPath, bunfig);
+
+    const cmds = [
+      [bunExe(), "run", mainPath],
+      [bunExe(), mainPath],
+    ];
+
+    for (let cmd of cmds) {
+      const { stderr, exitCode, stdout } = spawnSync({
+        cmd,
+        cwd: preloadDir,
+        stderr: "pipe",
+        stdout: "pipe",
+        env: bunEnv,
+      });
+
+      expect(stderr.toString()).toContain("preload test failed");
+      expect(stdout.toString()).toBe("");
+      expect(exitCode).toBe(1);
+    }
+  });
+
+  test("throws an error when preloaded module not found", async () => {
+    const bunfig = `preload = ["./bad-file.js"]`;
+
+    const preloadDir = join(realpathSync(tmpdir()), "bun-preload-test2");
+    mkdirSync(preloadDir, { recursive: true });
+    const preloadPath = join(preloadDir, "preload.js");
+    const mainPath = join(preloadDir, "main.js");
+    const bunfigPath = join(preloadDir, "bunfig.toml");
+    await Bun.write(preloadPath, preloadModule);
+    await Bun.write(mainPath, mainModule);
+    await Bun.write(bunfigPath, bunfig);
+
+    const cmds = [
+      [bunExe(), "run", mainPath],
+      [bunExe(), mainPath],
+    ];
+
+    for (let cmd of cmds) {
+      const { stderr, exitCode, stdout } = spawnSync({
+        cmd,
+        cwd: preloadDir,
+        stderr: "pipe",
+        stdout: "pipe",
+        env: bunEnv,
+      });
+
+      expect(stderr.toString()).toContain("preload not found ");
+      expect(stdout.toString()).toBe("");
+      expect(exitCode).toBe(1);
+    }
+  });
+});