feat: Add require-variable-type rule

.README/rules/require-variable-type.md

@@ -0,0 +1,5 @@
+### `require-variable-type`
+
+Requires that all variable declarators have type annotations.
+
+<!-- assertions requireVariableType -->

src/index.js

@@ -4,6 +4,7 @@ import noWeakTypes from './rules/noWeakTypes';
 import requireParameterType from './rules/requireParameterType';
 import requireReturnType from './rules/requireReturnType';
 import requireValidFileAnnotation from './rules/requireValidFileAnnotation';
+import requireVariableType from './rules/requireVariableType';
 import semi from './rules/semi';
 import spaceAfterTypeColon from './rules/spaceAfterTypeColon';
 import spaceBeforeGenericBracket from './rules/spaceBeforeGenericBracket';
@@ -34,6 +35,7 @@ export default {
     'require-parameter-type': requireParameterType,
     'require-return-type': requireReturnType,
     'require-valid-file-annotation': requireValidFileAnnotation,
+    'require-variable-type': requireVariableType,
     semi,
     'sort-keys': sortKeys,
     'space-after-type-colon': spaceAfterTypeColon,
@@ -54,6 +56,7 @@ export default {
     'object-type-delimiter': 0,
     'require-parameter-type': 0,
     'require-return-type': 0,
+    'require-variable-type': 0,
     semi: 0,
     'sort-keys': 0,
     'space-after-type-colon': 0,

src/rules/requireVariableType.js

@@ -0,0 +1,33 @@
+import _ from 'lodash';
+import {
+    isFlowFile,
+    quoteName
+} from './../utilities';
+
+export default (context) => {
+  const checkThisFile = !_.get(context, 'settings.flowtype.onlyFilesWithFlowAnnotation') || isFlowFile(context);
+
+  if (!checkThisFile) {
+    return () => {};
+  }
+
+  return {
+    VariableDeclaration: (variableDeclaration) => {
+      _.forEach(variableDeclaration.declarations, (variableDeclarator) => {
+        const identifierNode = _.get(variableDeclarator, 'id');
+        const typeAnnotation = _.get(identifierNode, 'typeAnnotation');
+        const identifierName = _.get(identifierNode, 'name');
+
+        if (!typeAnnotation) {
+          context.report({
+            data: {
+              name: quoteName(identifierName)
+            },
+            message: 'Missing {{name}}variable type annotation.',
+            node: identifierNode
+          });
+        }
+      });
+    }
+  };
+};

tests/rules/assertions/requireVariableType.js

@@ -0,0 +1,29 @@
+export default {
+  invalid: [
+    {
+      code: 'var foo = "bar"',
+      errors: [
+        {
+          message: 'Missing "foo" variable type annotation.'
+        }
+      ]
+    },
+    {
+      code: 'var foo : string = "bar", bar = 1',
+      errors: [
+        {
+          message: 'Missing "bar" variable type annotation.'
+        }
+      ]
+    }
+
+  ],
+  valid: [
+    {
+      code: 'var foo : string = "bar"'
+    },
+    {
+      code: 'var foo : string = "bar", bar : number = 1'
+    }
+  ]
+};

tests/rules/index.js

@@ -17,6 +17,7 @@ const reportingRules = [
   'require-parameter-type',
   'require-return-type',
   'require-valid-file-annotation',
+  'require-variable-type',
   'semi',
   'sort-keys',
   'space-after-type-colon',