Add ESM/CJS import tests

package.json

@@ -117,6 +117,7 @@
     "eslint": "^8.53.0",
     "eslint-config-prettier": "^9.0.0",
     "eslint-plugin-prettier": "^5.0.1",
+    "flatted": "^3.3.1",
     "get-port": "^7.0.0",
     "http-mitm-proxy": "^1.1.0",
     "make-synchronous": "^1.0.0",

test/import.test.ts

@@ -0,0 +1,91 @@
+// Type checking is disabled in this file because we want type checking to work without the `/dist/`
+// directory being populated.
+import { spawn } from "child_process";
+import path from "path";
+import { fileURLToPath } from "url";
+
+import test from "ava";
+import flatted from "flatted";
+
+// Any `require()` statements actually get treated as ESM imports under the hood in the tests, so
+// this is a kind of hacky way to perform the module import in a subprocess. Because we're only
+// really interested in whether the different builds and import types work in these tests, this
+// should be good enough.
+const requireCjs = async (
+  modulePath: string,
+): Promise<{ [key: string]: unknown }> => {
+  const __dirname = path.dirname(fileURLToPath(import.meta.url));
+  const moduleFullPath = path.resolve(__dirname, modulePath);
+  const subprocessCode = `
+    // Necessary for the browser tests.
+    global.window = {};
+
+    // Use flatted for better handling of non-JSON content, circular referecnes, etc.
+    const { stringify } = require("flatted");
+
+    const module = require("${moduleFullPath}");
+    process.stdout.write(stringify(module));
+  `;
+
+  return new Promise((resolve, reject) => {
+    const subprocess = spawn("node", ["-e", subprocessCode], {
+      stdio: ["inherit", "pipe", "pipe"],
+    });
+
+    let stdout = "";
+    subprocess.stdout.on("data", (chunk) => {
+      stdout += chunk;
+    });
+
+    let stderr = "";
+    subprocess.stderr.on("data", (chunk) => {
+      stderr += chunk;
+    });
+
+    subprocess.on("close", (code) => {
+      if (code === 0) {
+        try {
+          const result = flatted.parse(stdout);
+          resolve(result);
+        } catch (error) {
+          reject(new Error(`Failed to parse subprocess output:\n\n${stdout}`));
+        }
+      } else {
+        reject(new Error(`Subprocess exited with code ${code}:\n\n${stderr}`));
+      }
+    });
+  });
+};
+
+test.before(() => {
+  global.window = {} as Window & typeof globalThis;
+});
+
+test("cli", async (t) => {
+  const cli = await requireCjs("../dist/cli/index.js");
+  t.truthy(cli?.program);
+});
+
+test("lib browser cjs", async (t) => {
+  const lib = await requireCjs("../dist/lib/browser/index.js");
+  t.truthy(lib);
+  t.false("default" in lib, "library should not be nested under `default`");
+});
+
+test("lib browser mjs", async (t) => {
+  const { default: lib } = await import("../dist/lib/browser/index.mjs");
+  t.truthy(lib);
+  t.false("default" in lib, "library should not be nested under `default`");
+});
+
+test("lib node cjs", async (t) => {
+  const lib = await requireCjs("../dist/lib/index.js");
+  t.truthy(lib);
+  t.false("default" in lib, "library should not be nested under `default`");
+});
+
+test("lib node mjs", async (t) => {
+  const { default: lib } = await import("../dist/lib/index.mjs");
+  t.truthy(lib);
+  t.false("default" in lib, "library should not be nested under `default`");
+});

tsconfig.json

@@ -13,5 +13,5 @@
     "preserveConstEnums": true
   },
   "include": ["src/**/*", "test/**/*"],
-  "exclude": ["dist/**/*", "node_modules/**/*"]
+  "exclude": ["dist/**/*", "node_modules/**/*", "test/import.test.ts"]
 }

yarn.lock

@@ -2351,6 +2351,11 @@ flatted@^3.2.9:
   resolved "https://registry.npmjs.org/flatted/-/flatted-3.2.9.tgz"
   integrity sha512-36yxDn5H7OFZQla0/jFJmbIKTdZAQHngCedGxiMmpNfEZM0sdEeT+WczLQrjK6D7o2aiyLYDnkw0R3JK0Qv1RQ==
 
+flatted@^3.3.1:
+  version "3.3.1"
+  resolved "https://registry.yarnpkg.com/flatted/-/flatted-3.3.1.tgz#21db470729a6734d4997002f439cb308987f567a"
+  integrity sha512-X8cqMLLie7KsNUDSdzeN8FYK9rEt4Dt67OsG/DNGnYTSDBG4uFAJFBnUeiV+zCVAvwFy56IjM9sH51jVaEhNxw==
+
 follow-redirects@^1.15.0:
   version "1.15.3"
   resolved "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.15.3.tgz"
@@ -2966,7 +2971,7 @@ json-stable-stringify@^1.0.2:
 
 json-stringify-safe@^5.0.1:
   version "5.0.1"
-  resolved "https://registry.npmjs.org/json-stringify-safe/-/json-stringify-safe-5.0.1.tgz"
+  resolved "https://registry.yarnpkg.com/json-stringify-safe/-/json-stringify-safe-5.0.1.tgz#1296a2d58fd45f19a0f6ce01d65701e2c735b6eb"
   integrity sha512-ZClg6AaYvamvYEE82d3Iyd3vSSIjQ+odgjaTzRuO3s7toCdFKczob2i0zCh7JE8kWn17yvAWhUVxvqGwUalsRA==
 
 jsonfile@^6.0.1: