Check if yarn installed before asking (#249)

* check if yarn installed

* ask for package manager if yarn installed

* bump version to 1.1.5

package.json

@@ -1,6 +1,6 @@
 {
     "name": "superplate-cli",
-    "version": "1.1.4",
+    "version": "1.1.5",
     "description": "The frontend boilerplate with superpowers",
     "license": "MIT",
     "repository": {

src/Helper/binary/index.spec.ts

@@ -0,0 +1,7 @@
+import { BinaryHelper } from "./";
+
+describe("Binary Helper", () => {
+    it("has CanUseYarn function", async () => {
+        expect(typeof BinaryHelper.CanUseYarn).toBe("function");
+    });
+});

src/Helper/binary/index.ts

@@ -0,0 +1,12 @@
+import { execSync } from "child_process";
+
+export const BinaryHelper = {
+    CanUseYarn: (): boolean => {
+        try {
+            execSync("yarn --version", { stdio: "ignore" });
+            return true;
+        } catch (e) {
+            return false;
+        }
+    },
+};

src/Helper/index.ts

@@ -16,3 +16,4 @@ export { UrlHelper } from "./url";
 export { GitHelper } from "./git";
 export { FSHelper } from "./fs";
 export { tips } from "./tips";
+export { BinaryHelper } from "./binary";

src/saofile.ts

@@ -15,6 +15,7 @@ import {
     mergeBabel,
     tips,
     mergePluginData,
+    BinaryHelper,
 } from "@Helper";
 
 const saoConfig: GeneratorConfig = {
@@ -37,16 +38,20 @@ const saoConfig: GeneratorConfig = {
                 message: "What will be the name of your app",
                 default: appName,
             },
-            {
-                name: "pm",
-                message: "Package manager:",
-                choices: [
-                    { message: "Npm", value: "npm" },
-                    { message: "Yarn", value: "yarn" },
-                ],
-                type: "select",
-                default: "npm",
-            },
+            ...(BinaryHelper.CanUseYarn()
+                ? [
+                      {
+                          name: "pm",
+                          message: "Package manager:",
+                          choices: [
+                              { message: "Npm", value: "npm" },
+                              { message: "Yarn", value: "yarn" },
+                          ],
+                          type: "select",
+                          default: "npm",
+                      },
+                  ]
+                : []),
             ...(sourcePrompts?.prompts ?? []),
         ];
     },