New: support TypeScript at config initializer (fixes #11789) (#12172)

* New: support TypeScript at config initializer (fixes #11789)

* fix lint

* tiny fixes

Author: g-plane

lib/init/config-initializer.js

@@ -120,6 +120,12 @@ function getModulesList(config, installESLint) {
         }
     }
 
+    const parser = config.parser || (config.parserOptions && config.parserOptions.parser);
+
+    if (parser) {
+        modules[parser] = "latest";
+    }
+
     if (installESLint === false) {
         delete modules.eslint;
     } else {
@@ -291,6 +297,20 @@ function processAnswers(answers) {
         config.extends.push("plugin:vue/essential");
     }
 
+    if (answers.typescript) {
+        if (answers.framework === "vue") {
+            config.parserOptions.parser = "@typescript-eslint/parser";
+        } else {
+            config.parser = "@typescript-eslint/parser";
+        }
+
+        if (Array.isArray(config.plugins)) {
+            config.plugins.push("@typescript-eslint");
+        } else {
+            config.plugins = ["@typescript-eslint"];
+        }
+    }
+
     // setup rules based on problems/style enforcement preferences
     if (answers.purpose === "problems") {
         config.extends.unshift("eslint:recommended");
@@ -306,6 +326,9 @@ function processAnswers(answers) {
             config = autoconfig.extendFromRecommended(config);
         }
     }
+    if (answers.typescript && config.extends.includes("eslint:recommended")) {
+        config.extends.push("plugin:@typescript-eslint/eslint-recommended");
+    }
 
     // normalize extends
     if (config.extends.length === 0) {
@@ -465,6 +488,12 @@ function promptUser() {
                 { name: "None of these", value: "none" }
             ]
         },
+        {
+            type: "confirm",
+            name: "typescript",
+            message: "Does your project use TypeScript?",
+            default: false
+        },
         {
             type: "checkbox",
             name: "env",

tests/lib/init/config-initializer.js

@@ -168,6 +168,24 @@ describe("configInitializer", () => {
                 assert.deepStrictEqual(config.extends, ["eslint:recommended", "plugin:vue/essential"]);
             });
 
+            it("should enable typescript parser and plugin", () => {
+                answers.typescript = true;
+                const config = init.processAnswers(answers);
+
+                assert.strictEqual(config.parser, "@typescript-eslint/parser");
+                assert.deepStrictEqual(config.plugins, ["@typescript-eslint"]);
+                assert.deepStrictEqual(config.extends, ["eslint:recommended", "plugin:@typescript-eslint/eslint-recommended"]);
+            });
+
+            it("should enable typescript parser and plugin with vue", () => {
+                answers.framework = "vue";
+                answers.typescript = true;
+                const config = init.processAnswers(answers);
+
+                assert.strictEqual(config.parserOptions.parser, "@typescript-eslint/parser");
+                assert.deepStrictEqual(config.plugins, ["vue", "@typescript-eslint"]);
+            });
+
             it("should extend eslint:recommended", () => {
                 const config = init.processAnswers(answers);
 
@@ -317,6 +335,28 @@ describe("configInitializer", () => {
                 assert.include(modules, "eslint-plugin-vue@latest");
                 assert.include(modules, "eslint-config-standard@latest");
             });
+
+            it("should support custom parser", () => {
+                const config = {
+                    parser: "@typescript-eslint/parser"
+                };
+                const modules = init.getModulesList(config);
+
+                assert.include(modules, "@typescript-eslint/parser@latest");
+            });
+
+            it("should support custom parser with Vue.js", () => {
+                const config = {
+
+                    // We should declare the parser at `parserOptions` when using with `eslint-plugin-vue`.
+                    parserOptions: {
+                        parser: "@typescript-eslint/parser"
+                    }
+                };
+                const modules = init.getModulesList(config);
+
+                assert.include(modules, "@typescript-eslint/parser@latest");
+            });
         });
 
         describe("auto", () => {