Implement virtual module support in `Bun.plugin` (#6167)

* Add support for `build.module` in `Bun.plugin`

* Another test

* Update docs

* Update isBuiltinModule.cpp

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>
Co-authored-by: Dylan Conway <dylan.conway567@gmail.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/test/bundler/bun-build-api.test.ts b/test/bundler/bun-build-api.test.ts
index 3c2308d94..d1f1a10b8 100644
--- a/test/bundler/bun-build-api.test.ts
+++ b/test/bundler/bun-build-api.test.ts
@@ -290,4 +290,27 @@ describe("Bun.build", () => {
     // depends on the ws package in the test/node_modules.
     expect(content).toContain("var websocket = __toESM(require_websocket(), 1);");
   });
+
+  test("module() throws error", async () => {
+    expect(() =>
+      Bun.build({
+        entrypoints: [join(import.meta.dir, "./fixtures/trivial/bundle-ws.ts")],
+        plugins: [
+          {
+            name: "test",
+            setup: b => {
+              b.module("ad", () => {
+                return {
+                  exports: {
+                    hello: "world",
+                  },
+                  loader: "object",
+                };
+              });
+            },
+          },
+        ],
+      }),
+    ).toThrow();
+  });
 });