Add bundling unit tests

tests/bundles.test.js

@@ -0,0 +1,37 @@
+import { spawnSync } from "child_process";
+
+const MODULE_NAME = "@huggingface/transformers";
+
+const CODE_BODY = `
+const model_id = "hf-internal-testing/tiny-random-LlamaForCausalLM";
+const generator = await pipeline("text-generation", model_id, { dtype: "fp32" });
+const result = await generator("hello", { max_new_tokens: 3, return_full_text: false });
+process.stdout.write(result[0].generated_text);
+`;
+
+const TARGET_OUTPUT = "erdingsAndroid Load";
+
+const wrap_async_iife = (code) => `(async function() { ${code} })();`;
+
+const check = (code, module = false) => {
+  const args = ["-e", code];
+  if (module) args.push("--input-type=module");
+  const { status, stdout, stderr } = spawnSync("node", args);
+  expect(stderr.toString()).toBe(""); // No warnings or errors are printed
+  expect(stdout.toString()).toBe(TARGET_OUTPUT); // The output should match
+  expect(status).toBe(0); // The process should exit cleanly
+};
+
+describe("Testing the bundle", () => {
+  it("ECMAScript Module (ESM)", () => {
+    check(`import { pipeline } from "${MODULE_NAME}";${CODE_BODY}`, true);
+  });
+
+  it("CommonJS (CJS) with require", () => {
+    check(`const { pipeline } = require("${MODULE_NAME}");${wrap_async_iife(CODE_BODY)}`);
+  });
+
+  it("CommonJS (CJS) with dynamic import", () => {
+    check(`${wrap_async_iife(`const { pipeline } = await import("${MODULE_NAME}");${CODE_BODY}`)}`);
+  });
+});