Add tests for determinePackageManager

package.json

@@ -34,7 +34,7 @@
     "test": "concurrently --group npm:test:*",
     "test:format": "prettier --check .",
     "test:lint": "eslint .",
-    "test:node": "node --test",
+    "test:node": "node --test --test-reporter spec",
     "update-template-deps": "(cd template && npx npm-check-updates@latest --upgrade)"
   },
   "dependencies": {

src/main.mjs

@@ -19,7 +19,7 @@ const templatePath = pathJoin(__dirname, "..", "template");
 debug("__dirname", __dirname);
 debug("templatePath", templatePath);
 
-export const derivePackageManager = () => {
+export const determinePackageManager = () => {
   const npmUserAgent = env.npm_config_user_agent;
   debug("npmUserAgent", npmUserAgent);
   const npmExecPath = env.npm_execpath;
@@ -79,7 +79,7 @@ export const create = async () => {
   const { projectName, projectPath } = deriveProjectNameAndPath(argv[2]);
   debug("projectName", projectName);
   debug("projectPath", projectPath);
-  const packageManagerType = derivePackageManager();
+  const packageManagerType = determinePackageManager();
   debug("packageManagerType", packageManagerType);
   const packageManagerRun =
     packageManagerType === "npm" ? "npm run"

src/test.mjs

@@ -2,8 +2,8 @@ import test from "node:test";
 import assert from "node:assert/strict";
 import { tmpdir } from "node:os";
 import { join as pathJoin } from "node:path";
-
-import { deriveProjectNameAndPath } from "./main.mjs";
+import { env } from "node:process";
+import { deriveProjectNameAndPath, determinePackageManager } from "./main.mjs";
 
 test("deriveProjectNameAndPath", async (t) => {
   const dir = tmpdir();
@@ -42,3 +42,29 @@ test("deriveProjectNameAndPath", async (t) => {
     assert.equal(projectPath, pathJoin(dir, "test"));
   });
 });
+
+test("determinePackageManager", async (t) => {
+  let npmUserAgent;
+  t.beforeEach(() => {
+    npmUserAgent = env.npm_config_user_agent;
+  });
+  t.afterEach(() => {
+    env.npm_config_user_agent = npmUserAgent;
+  });
+
+  await t.test("with npm", (_t) => {
+    env.npm_config_user_agent =
+      "npm/10.7.0 node/v18.20.4 linux x64 workspaces/false ci/github-actions";
+    assert.equal(determinePackageManager(), "npm");
+  });
+
+  await t.test("with yarn", (_t) => {
+    env.npm_config_user_agent = "yarn/1.22.22 npm/? node/v20.15.1 darwin arm64";
+    assert.equal(determinePackageManager(), "yarn");
+  });
+
+  await t.test("with pnpm", (_t) => {
+    env.npm_config_user_agent = "pnpm/9.6.0 npm/? node/v22.5.1 win32 x64";
+    assert.equal(determinePackageManager(), "pnpm");
+  });
+});