feat: mapDispatchToProps-prefer-object

feat: mapDispatchToProps-prefer-object

Author: DianaSuvorova

.gitignore

@@ -1 +1,2 @@
 node_modules
+package-lock.json

README.md

@@ -45,6 +45,7 @@ Then configure the rules you want to use under the rules section.
 
 * [react-redux/connect-prefer-minimum-two-arguments](docs/rules/connect-prefer-minimum-two-arguments.md) Enforces that connect function has at least 2 arguments.
 * [react-redux/connect-prefer-named-arguments](docs/rules/connect-prefer-named-arguments.md) Enforces that all connect arguments have specific names.
+* [react-redux/mapDispatchToProps-prefer-object](docs/rules/mapDispatchToProps-prefer-object.md) Enforces that all mapDispatchToProps parameters have specific names.
+* [react-redux/mapDispatchToProps-prefer-parameters-names](docs/rules/mapDispatchToProps-prefer-parameters-names.md)  Enforces that mapDispatchToProps returns an object.
 * [react-redux/mapStateToProps-prefer-parameters-names](docs/rules/mapStateToProps-prefer-parameters-names.md) Enforces that all mapStateToProps parameters have specific names.
-* [react-redux/mapDispatchToProps-prefer-parameters-names](docs/rules/mapDispatchToProps-prefer-parameters-names.md) Enforces that all mapDispatchToProps parameters have specific names.
 * [react-redux/prefer-separate-component-file](docs/rules/prefer-separate-component-file.md) Enforces that all connected components are defined in a separate file.

docs/rules/mapDispatchToProps-prefer-object.md

@@ -0,0 +1,30 @@
+#  Enforces that mapDispatchToProps returns an object. (react-redux/mapDispatchToProps-prefer-object)
+
+In most cases one just needs to pass an object with an actions. And connect wraps it into dispatch function.
+
+[react-redux documentation](https://github.com/reactjs/react-redux/blob/master/docs/api.md#arguments)
+> If an object is passed, each function inside it is assumed to be a Redux action creator. An object with the same function names, but with every action creator wrapped into a dispatch call so they may be invoked directly, will be merged into the component’s props.
+
+## Rule details
+
+The following pattern is considered incorrect:
+
+```js
+const mapDispatchToProps = (dispatch) => (
+        {
+            requestFilteredItems: (keyword) => {
+                dispatch(requestFilteredItems(keyword));
+            }
+        }
+    )
+```
+
+The following patterns are considered correct:
+
+```js
+const mapDispatchToProps = () => {}
+```
+
+```js
+const mapDispatchToProps = {anAction: anAction}
+```

index.js

@@ -1,8 +1,9 @@
 const rules = {
   'connect-prefer-minimum-two-arguments': require('./lib/rules/connect-prefer-minimum-two-arguments'),
   'connect-prefer-named-arguments': require('./lib/rules/connect-prefer-named-arguments'),
-  'mapStateToProps-prefer-parameters-names': require('./lib/rules/mapStateToProps-prefer-parameters-names'),
+  'mapDispatchToProps-prefer-object': require('./lib/rules/mapDispatchToProps-prefer-object'),
   'mapDispatchToProps-prefer-parameters-names': require('./lib/rules/mapDispatchToProps-prefer-parameters-names'),
+  'mapStateToProps-prefer-parameters-names': require('./lib/rules/mapStateToProps-prefer-parameters-names'),
   'prefer-separate-component-file': require('./lib/rules/prefer-separate-component-file'),
 };
 
@@ -24,8 +25,9 @@ module.exports = {
       rules: {
         'react-redux/connect-prefer-minimum-two-arguments': 0,
         'react-redux/connect-prefer-named-arguments': 2,
-        'react-redux/mapStateToProps-prefer-parameters-names': 2,
         'react-redux/mapDispatchToProps-prefer-parameters-names': 2,
+        'react-redux/mapDispatchToProps-prefer-object': 2,
+        'react-redux/mapStateToProps-prefer-parameters-names': 2,
         'react-redux/prefer-separate-component-file': 1,
       },
     },

lib/rules/mapDispatchToProps-prefer-object.js

@@ -0,0 +1,28 @@
+const report = function (context, node) {
+  context.report({
+    message: 'mapDispatchToProps should return object',
+    node,
+  });
+};
+
+const checkDeclaration = function (context, node) {
+  const init = (
+    node.id &&
+    node.id.name === 'mapDispatchToProps' &&
+    ((node.init && node.init.body) || node.body)
+  );
+  if (init && context.getSource(init) !== '{}') {
+    report(context, node);
+  }
+};
+
+module.exports = function (context) {
+  return {
+    VariableDeclaration(node) {
+      node.declarations.forEach(decl => checkDeclaration(context, decl));
+    },
+    FunctionDeclaration(node) {
+      checkDeclaration(context, node);
+    },
+  };
+};

tests/lib/rules/mapDispatchToProps-prefer-object.js

@@ -0,0 +1,36 @@
+require('babel-eslint');
+
+const rule = require('../../../lib/rules/mapDispatchToProps-prefer-object');
+const RuleTester = require('eslint').RuleTester;
+
+const parserOptions = {
+  ecmaVersion: 6,
+  sourceType: 'module',
+  ecmaFeatures: {
+    experimentalObjectRestSpread: true,
+  },
+};
+
+const ruleTester = new RuleTester({ parserOptions });
+
+ruleTester.run('mapDispatchToProps-prefer-object', rule, {
+  valid: [
+    'const mapDispatchToProps = {anAction: anAction}',
+    'const mapDispatchToProps = () => {}',
+    'function mapDispatchToProps () {}',
+  ],
+  invalid: [{
+    code: `const mapDispatchToProps = (dispatch) => (
+            {
+                requestFilteredItems: (client, keyword) => {
+                    dispatch(requestFilteredItems(client, keyword));
+                }
+            }
+        )`,
+    errors: [
+      {
+        message: 'mapDispatchToProps should return object',
+      },
+    ],
+  }],
+});

tests/lib/rules/mapDispatchToProps-prefer-parameters-names.js

@@ -18,6 +18,7 @@ ruleTester.run('mapDispatchToProps-prefer-parameters-names', rule, {
     'const mapDispatchToProps = (dispatch, ownProps) => {}',
     'const mapDispatchToProps = (dispatch) => {}',
     'const mapDispatchToProps = (dispatch, ownProps, moreArgs) => {}',
+    'const mapDispatchToProps = {anAction: anAction}',
   ],
   invalid: [{
     code: 'const mapDispatchToProps = (anyOtherName) => {}',