Flow ruleset

Author: arnostpleskot

.gitignore

@@ -19,6 +19,7 @@ node_modules
 *#
 .DS_STORE
 .netbeans
+.vscode
 nbproject
 .idea
 .node_history

README.md

@@ -46,6 +46,9 @@ See the [tutorial](tutorial) directory for lots of example config files.
 - @strv/javascript/environments/react/optional
 - @strv/javascript/environments/react/accessibility
 
+> These are rules for [Flow][flow-home] type checker.
+- @strv/javascript/environments/flow/recommended
+
 > This one includes rules which deal with how the code looks like and not how it works. It helps keep the code clean and consistent.
 
 - @strv/javascript/coding-styles/recommended
@@ -54,6 +57,10 @@ See the [tutorial](tutorial) directory for lots of example config files.
 
 - @strv/javascript/coding-styles/fixable
 
+> This one contains coding style rules for Flow
+
+- @strv/javascript/coding-styles/flow
+
 ## License
 
 This software is licensed under the **BSD-3-Clause License**. See the [LICENSE](LICENSE) file for more information.
@@ -64,3 +71,4 @@ This software is licensed under the **BSD-3-Clause License**. See the [LICENSE](
 [travis-url]: https://travis-ci.org/strvcom/eslint-config-javascript
 [eslint-version]: https://img.shields.io/badge/ESLint->=4.5.0-brightgreen.svg
 [eslint-fixing]: http://eslint.org/docs/user-guide/command-line-interface#fix
+[flow-home]: https://flow.org

coding-styles/flow.js

@@ -0,0 +1,45 @@
+/**
+ * Js-coding-standards
+ *
+ * @author      Arnost Pleskot <[email protected]>
+ * @copyright   2017 STRV
+ * @license     http://choosealicense.com/licenses/bsd-3-clause  BSD-3-Clause License
+ */
+
+'use strict'
+
+module.exports = {
+  plugins: [
+    'flowtype',
+  ],
+
+  rules: {
+    // Enforces a particular style for boolean type annotations.
+    'flowtype/boolean-style': ['warn', 'boolean'],
+
+    // Enforces consistent spacing within generic type annotation parameters.
+    'flowtype/generic-spacing': ['warn', 'never'],
+
+    // Enforces consistent separators between properties in Flow object types.
+    'flowtype/object-type-delimiter': ['warn', 'comma'],
+
+    // Enforces consistent use of trailing commas in Object and Tuple annotations.
+    // This rule takes one argument which mirrors ESLint's default comma-dangle rule.
+    'flowtype/delimiter-dangle': ['warn', 'always-multiline'],
+
+    // Enforces consistent use of semicolons after type aliases.
+    'flowtype/semi': ['warn', 'never'],
+
+    // Enforces consistent spacing after the type annotation colon.
+    'flowtype/space-after-type-colon': ['warn', 'always'],
+
+    // Enforces consistent spacing before the opening < of generic type annotation parameters.
+    'flowtype/space-before-generic-bracket': ['warn', 'never'],
+
+    // Enforces consistent spacing before the type annotation colon.
+    'flowtype/space-before-type-colon': ['warn', 'never'],
+
+    // Enforces consistent spacing around union and intersection type separators (` | ` and ` & `).
+    'flowtype/union-intersection-spacing': ['warn', 'always'],
+  },
+}

environments/flow/README.md

@@ -0,0 +1,19 @@
+# Flow
+
+These configuration files are suitable to lint Flow type annotations.
+
+## Configurations
+
+### @strv/javascript/environments/flow/recommended
+
+Basic ruleset for Flow. Main focus is on consistent way to write type annotations.
+
+### In combination with React
+
+If you are using Flow with React to [validate props](https://flow.org/en/docs/react/components/#toc-class-components) consider adding this rule to your `.eslintrc.js` config:
+
+```js
+// Enforces sorting of Object annotations.
+// This rule mirrors ESlint's sort-keys rule.
+'flowtype/sort-keys': ['warn', 'asc', { caseSensitive: false }]
+```

environments/flow/recommended.js

@@ -0,0 +1,48 @@
+/**
+ * Js-coding-standards
+ *
+ * @author      Arnost Pleskot <[email protected]>
+ * @copyright   2017 STRV
+ * @license     http://choosealicense.com/licenses/bsd-3-clause  BSD-3-Clause License
+ */
+
+'use strict'
+
+module.exports = {
+  plugins: [
+    'flowtype',
+  ],
+
+  rules: {
+    // Marks Flow type identifiers as defined.
+    // Used to suppress no-undef reporting of type identifiers.
+    'flowtype/define-flow-type': 'warn',
+
+    // Checks for duplicate properties in Object annotations.
+    'flowtype/no-dupe-keys': 'error',
+
+    // Disallows use of primitive constructors as types, such as Boolean, Number and String.
+    'flowtype/no-primitive-constructor-types': 'error',
+
+    // Disallows Flow type imports, exports, aliases, and annotations in files missing a valid
+    // Flow file declaration (or a @noflow annotation).
+    'flowtype/no-types-missing-file-annotation': 'error',
+
+    // Warns against weak type annotations any, Object and Function. These types can cause flow
+    // to silently skip over portions of your code, which would have otherwise caused type errors.
+    'flowtype/no-weak-types': ['warn', { any: true }],
+
+    // Requires that all function parameters have type annotations.
+    'flowtype/require-parameter-type': 'error',
+
+    // Requires that functions have return type annotation.
+    'flowtype/require-return-type': ['error', 'always'],
+
+    // Requires that all variable declarators have type annotations.
+    'flowtype/require-variable-type': 'error',
+
+    // Marks Flow type alias declarations as used.
+    // Used to suppress no-unused-vars errors that are triggered by type aliases.
+    'flowtype/use-flow-type': 'warn',
+  },
+}

package-lock.json

@@ -8,6 +8,7 @@
   },
   "contributors": [],
   "dependencies": {
+    "eslint-plugin-flowtype": "^2.35.0",
     "eslint-plugin-import": "^2.7.0",
     "eslint-plugin-jsx-a11y": "^6.0.2",
     "eslint-plugin-react": "^7.3.0"

package.json

@@ -168,5 +168,12 @@ module.exports = {
 
     // Enforce React components to have a shouldComponentUpdate method
     'react/require-optimization': 0,
+
+    // Enforces sorting of Object annotations.
+    // This rule mirrors ESlint's sort-keys rule.
+    'flowtype/sort-keys': 0,
+
+    // Enforces a consistent naming pattern for type aliases.
+    'flowtype/type-id-match': 0,
   },
 }