test(bundler): add regression test for plugin transform import.meta.url

Add a regression test for GitHub issue #26653 which reported that transitive dependencies could incorrectly use real filesystem paths instead of virtual /$bunfs/ paths in standalone builds when a plugin transforms files. The test verifies that when a plugin's onLoad callback transforms a file, the transitive dependencies (files imported by the transformed file) still correctly have import.meta.url pointing to the virtual filesystem path rather than the original filesystem path. Testing shows the basic behavior is correct - this test ensures it stays that way. The original issue may only manifest in very large codebases (70+ transformed files). Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2026-02-02 15:08:46 +00:00 · 2026-02-01 06:05:45 +00:00
parent a14a89ca95
commit 7ab2b36495
1 changed files with 61 additions and 0 deletions
--- a/test/bundler/bundler_compile.test.ts
+++ b/test/bundler/bundler_compile.test.ts
@@ -935,4 +935,65 @@ const server = serve({
    const result = await Bun.$`./app`.cwd(dir).env(bunEnv).nothrow();
    expect(result.stdout.toString().trim()).toBe("IT WORKS");
  });
+
+  // Regression test for https://github.com/oven-sh/bun/issues/26653
+  // When a plugin transforms a file's content, transitive dependencies should
+  // still have correct import.meta.url pointing to the virtual /$bunfs/ path,
+  // not the original filesystem path.
+  itBundled("compile/PluginTransformPreservesTransitiveImportMetaUrl", {
+    compile: true,
+    backend: "api",
+    outfile: "dist/out",
+    files: {
+      "/entry.ts": /* js */ `
+        import { processData } from "./model.ts";
+        const result = processData();
+        console.log("Result:", result);
+      `,
+      "/model.ts": /* js */ `
+        // This file is transformed by a plugin - it uses a placeholder
+        // that gets replaced with the actual filesystem path
+        import { helper } from "./utils.ts";
+        const MODEL_URL = "MODEL_URL_PLACEHOLDER";
+        export function processData() {
+          console.log("Model URL:", MODEL_URL);
+          return helper();
+        }
+      `,
+      "/utils.ts": /* js */ `
+        // This transitive dependency is NOT transformed by the plugin.
+        // Its import.meta.url should point to the virtual /$bunfs/ path,
+        // not the original filesystem path.
+        export function helper() {
+          const url = import.meta.url;
+          console.log("Utils URL:", url);
+          // Verify the URL is the virtual path
+          if (url.includes("/$bunfs/") || url.includes("B:\\\\~BUN\\\\")) {
+            return "success";
+          } else {
+            return "FAIL: import.meta.url is not virtual path: " + url;
+          }
+        }
+      `,
+    },
+    plugins: [
+      {
+        name: "transform-model",
+        setup(api) {
+          api.onLoad({ filter: /model\.ts$/ }, async args => {
+            const { pathToFileURL } = await import("url");
+            const contents = await Bun.file(args.path).text();
+            // Replace placeholder with actual filesystem path
+            const fileUrl = pathToFileURL(args.path).href;
+            const transformed = contents.replace("MODEL_URL_PLACEHOLDER", fileUrl);
+            return { contents: transformed, loader: "ts" };
+          });
+        },
+      },
+    ],
+    run: {
+      // The output should show success from utils.ts, verifying import.meta.url is correct
+      stdout: /Result: success/,
+    },
+  });
 });