feat(packager): add feature to detect Yarn version

Author: hckhanh

src/checker.ts

@@ -1,8 +1,14 @@
-import { getFileStats, withCurrentDir } from "./process";
+import { getFileStats, readCurrentDir, withCurrentDir } from "./process";
 
 export async function checkPackageJson() {
   const stats = await getFileStats(withCurrentDir("package.json"));
   if (!stats) {
     throw new Error("package.json is not found. Must be run in existing project directory.");
   }
 }
+
+export async function detectYarnVersion(): Promise<"yarn" | "yarn2"> {
+  const dirents = await readCurrentDir();
+  const yarnConfigs = dirents.find((dirent) => dirent.name === ".yarn");
+  return yarnConfigs && yarnConfigs.isDirectory() ? "yarn2" : "yarn";
+}

src/index.ts

@@ -36,7 +36,7 @@ class CreateJavascriptProject extends Command {
     const formatter = formatterFactory.createFormatter(answers.format);
 
     const packagerFactory = PackagerFactory.getInstance();
-    const packager = packagerFactory.createPackager(answers);
+    const packager = await packagerFactory.createPackager(answers.packager);
 
     const generatorFactory = GeneratorFactory.getInstance();
     const generators = answers.configurations.map((type) =>

src/packagers/PackagerFactory.ts

@@ -1,4 +1,5 @@
-import { InquirerConfigs } from "../types";
+import { detectYarnVersion } from "../checker";
+import { PackagerType } from "../types";
 import { NpmPackager } from "./NpmPackager";
 import { Packager } from "./Packager";
 import { Yarn2Packager } from "./Yarn2Packager";
@@ -14,19 +15,21 @@ export class PackagerFactory {
     return this.factory;
   }
 
-  createPackager(configs: InquirerConfigs): Packager {
-    if (configs.configurations.includes("yarn2")) {
-      return new Yarn2Packager();
-    }
+  async createPackager(type: PackagerType): Promise<Packager> {
+    if (type === "yarn") {
+      const yarnVersion = await detectYarnVersion();
+
+      if (yarnVersion === "yarn2") {
+        return new Yarn2Packager();
+      }
 
-    if (configs.packager === "yarn") {
       return new YarnPackager();
     }
 
-    if (configs.packager === "npm") {
+    if (type === "npm") {
       return new NpmPackager();
     }
 
-    throw new Error(`"${configs.packager}" packager not implemented.`);
+    throw new Error(`"${type}" packager not implemented.`);
   }
 }

src/process.ts

@@ -1,6 +1,6 @@
 import { ChildProcessWithoutNullStreams } from "child_process";
 import { spawn } from "cross-spawn";
-import { readFile, rm, stat, writeFile } from "fs/promises";
+import { readdir, readFile, rm, stat, writeFile } from "fs/promises";
 import { Stats } from "node:fs";
 import { join } from "path";
 
@@ -83,6 +83,10 @@ export async function removeFile(file: string) {
   await rm(file, { force: true });
 }
 
+export async function readCurrentDir() {
+  return readdir(currentDir, { withFileTypes: true });
+}
+
 export function formatJson(obj: object): string {
   return JSON.stringify(obj, null, 2);
 }