feat: add presets/es5 and presets/es5-prettier

Author: koba04

README.md

@@ -118,6 +118,16 @@ module.exports = {
 };
 ```
 
+### [Experimental] `@cybozu/eslint-config/presets/es5`
+
+This rule set is for projects using ES5.
+
+```js
+module.exports = {
+  extends: "@cybozu/eslint-config/presets/es5"
+};
+```
+
 ## [Experimental] Prettier Support
 
 Prettier is a code formatter, which supports not only JavaScript but also other languages.
@@ -139,5 +149,6 @@ In order to this, you have to install `prettier` and choose a preset from the fo
 - `@cybozu/eslint-config/presets/prettier`
 - `@cybozu/eslint-config/presets/react-prettier`
 - `@cybouz/eslint-config/presets/react-flowtype-prettier`
+- `@cybouz/eslint-config/presets/es5-prettier`
 
 **Currently, we don't support customized Prettier config**

lib/es5.js

@@ -0,0 +1,52 @@
+const base = require("./base");
+
+const baseRules = base.rules;
+// This rule can be parsed with ES5
+delete baseRules["import/no-duplicates"];
+
+module.exports = {
+  extends: ["eslint:recommended"],
+  parserOptions: {
+    ecmaVersion: 5,
+    sourceType: "script"
+  },
+  env: {
+    browser: true,
+    commonjs: true
+  },
+  rules: Object.assign({}, baseRules, {
+    // Disable all rules about ES6
+    "arrow-body-style": "off",
+    "arrow-parens": "off",
+    "arrow-spacing": "off",
+    "constructor-super": "off",
+    "generator-star-spacing": "off",
+    "no-class-assign": "off",
+    "no-confusing-arrow": "off",
+    "no-const-assign": "off",
+    "no-dupe-class-members": "off",
+    "no-duplicate-imports": "off",
+    "no-new-symbol": "off",
+    "no-restricted-imports": "off",
+    "no-this-before-super": "off",
+    "no-useless-computed-key": "off",
+    "no-useless-constructor": "off",
+    "no-useless-rename": "off",
+    "no-var": "off",
+    "object-shorthand": "off",
+    "prefer-arrow-callback": "off",
+    "prefer-const": "off",
+    "prefer-destructuring": "off",
+    "prefer-numeric-literals": "off",
+    "prefer-reflect": "off",
+    "prefer-rest-params": "off",
+    "prefer-spread": "off",
+    "prefer-template": "off",
+    "require-yield": "off",
+    "rest-spread-spacing": "off",
+    "sort-imports": "off",
+    "symbol-description": "off",
+    "template-curly-spacing": "off",
+    "yield-star-spacing": "off"
+  })
+};

presets/es5-prettier.js

@@ -0,0 +1,3 @@
+module.exports = {
+  extends: ["../lib/es5.js", "../lib/prettier.js"]
+};

presets/es5.js

@@ -0,0 +1,3 @@
+module.exports = {
+  extends: ["../lib/es5.js"]
+};

test/es5-test.js

@@ -0,0 +1,17 @@
+const assert = require("assert");
+const runLintWithFixtures = require("./lib/runLintWithFixtures");
+
+describe("es5", () => {
+  it("should get expected errors and warninigs with es5 config", () => {
+    const result = runLintWithFixtures("es5");
+    assert.deepStrictEqual(result, {
+      "error.js": {
+        errors: ["no-unused-vars", "no-redeclare"]
+      },
+      "warning.js": {
+        warnings: ["array-callback-return"]
+      },
+      "ok.js": {}
+    });
+  });
+});

test/fixtures/es5/error.js

@@ -0,0 +1,3 @@
+var obj = {};
+var obj = {};
+

test/fixtures/es5/ok.js

@@ -0,0 +1,4 @@
+var foos = [''];
+foos.map(function(foo) {
+  return foo + foo;
+});

test/fixtures/es5/warning.js

@@ -0,0 +1,8 @@
+var a = 1;
+var b = 2;
+
+alert(a + b);
+
+[].map(function(v) {
+  alert(v);
+});