Test interop with template-colocation-plugin

This test demonstrates the failure from #16

I think the fix will go in `@embroider/shared-internals` but once it does this will tell us if we got it right.

package.json

@@ -35,6 +35,7 @@
     "@babel/plugin-proposal-decorators": "^7.23.3",
     "@babel/plugin-transform-class-properties": "^7.23.3",
     "@babel/plugin-transform-private-methods": "^7.23.3",
+    "@embroider/shared-internals": "^2.5.1",
     "@swc-node/register": "^1.6.8",
     "@types/babel__core": "^7.20.4",
     "@types/node": "^20.9.1",

tests/helpers.ts

@@ -17,9 +17,10 @@ try {
   );
 }
 
-function builder(
+export function builder(
   exprPlugins: TransformOptions["plugins"],
-  modulePlugins?: TransformOptions["plugins"]
+  modulePlugins?: TransformOptions["plugins"],
+  filename = "example.js"
 ): Builder {
   function expression(src: string, scope: Record<string, any>) {
     let transformedSrc = transform(
@@ -28,7 +29,7 @@ function builder(
     return (${src})
    })
   `,
-      { plugins: exprPlugins }
+      { plugins: exprPlugins, filename }
     )!.code!;
     let fn = eval(transformedSrc);
     return fn(...Object.values(scope));
@@ -37,6 +38,7 @@ function builder(
   async function module(src: string, deps: Record<string, any>) {
     let transformedSrc = transform(src, {
       plugins: modulePlugins ?? exprPlugins,
+      filename,
     })!.code!;
     let context = vm.createContext({ deps });
     let m: vm.SourceTextModule;

tests/plugin-interop-test.ts

@@ -0,0 +1,79 @@
+import { module, test } from "qunit";
+import { builder, Builder } from "./helpers.ts";
+import { type LegacyClassDecorator } from "../src/runtime.ts";
+import * as runtimeImpl from "../src/runtime.ts";
+import ourDecorators from "../src/index.ts";
+import { createRequire } from "node:module";
+import { mkdtemp, writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+
+const require = createRequire(import.meta.url);
+const Colocation = require("@embroider/shared-internals/src/template-colocation-plugin");
+
+module("plugin-interop", (hooks) => {
+  let build: Builder;
+
+  hooks.before(async () => {
+    let dir = await mkdtemp(join(tmpdir(), "decorator-transforms-"));
+    await writeFile(join(dir, "example.hbs"), "");
+    build = builder(
+      [],
+      [
+        [
+          ourDecorators,
+          { runtime: { import: "decorator-transforms/runtime" } },
+        ],
+        [Colocation],
+      ],
+      join(dir, "example.js")
+    );
+  });
+
+  test("colocation", async (assert) => {
+    let red: LegacyClassDecorator = (target) => {
+      return class extends target {
+        get red() {
+          return "#ff0000";
+        }
+      };
+    };
+
+    let setComponents = 0;
+
+    let { default: Example } = await build.module(
+      `
+        import red from "red";
+        import { precompileTemplate } from '@ember/template-compilation';
+
+        const __COLOCATED_TEMPLATE__ = precompileTemplate("Hello world")
+
+        @red 
+        export default class Example {
+        }
+
+      `,
+      {
+        "decorator-transforms/runtime": runtimeImpl,
+        red: { default: red },
+        "@ember/component": {
+          setComponentTemplate: function (_template: unknown, obj: unknown) {
+            setComponents++;
+            return obj;
+          },
+        },
+        "@ember/template-compilation": {
+          precompileTemplate: function (a: string) {
+            return a;
+          },
+        },
+        "./example.hbs": {
+          default: "",
+        },
+      }
+    );
+
+    assert.strictEqual(new Example().red, "#ff0000");
+    assert.strictEqual(setComponents, 1);
+  });
+});