feat: add variable declarations to colon spacing checks

src/rules/typeColonSpacing/evaluateVariables.js

@@ -0,0 +1,31 @@
+import _ from 'lodash';
+import {getParameterName, quoteName} from '../../utilities';
+
+export default (context, report) => {
+  const sourceCode = context.getSourceCode();
+
+  const getColon = (node, typeAnnotation) => {
+    if (node.type === 'FunctionTypeParam') {
+      return sourceCode.getFirstToken(node, node.optional ? 2 : 1);
+    } else {
+      return sourceCode.getFirstToken(typeAnnotation);
+    }
+  };
+
+  return (node) => {
+    const declarations = _.get(node, 'declarations', []);
+
+    _.forEach(declarations, (leaf) => {
+      const typeAnnotation = _.get(leaf, 'id.typeAnnotation');
+
+      if (typeAnnotation) {
+        report({
+          colon: getColon(leaf, typeAnnotation),
+          name: quoteName(getParameterName(leaf, context)),
+          node: leaf,
+          type: node.kind + ' type annotation'
+        });
+      }
+    });
+  };
+};

src/rules/typeColonSpacing/index.js

@@ -4,6 +4,7 @@ import evaluateObjectTypeProperty from './evaluateObjectTypeProperty';
 import evaluateTypeCastExpression from './evaluateTypeCastExpression';
 import evaluateTypical from './evaluateTypical';
 import evaluateFunctions from './evaluateFunctions';
+import evaluateVariables from './evaluateVariables';
 
 export default (direction, context, options) => {
   const report = reporter(direction, context, options);
@@ -13,6 +14,7 @@ export default (direction, context, options) => {
     ClassProperty: evaluateTypical(context, report, 'class property'),
     ObjectTypeIndexer: evaluateObjectTypeIndexer(context, report),
     ObjectTypeProperty: evaluateObjectTypeProperty(context, report),
-    TypeCastExpression: evaluateTypeCastExpression(context, report)
+    TypeCastExpression: evaluateTypeCastExpression(context, report),
+    VariableDeclaration: evaluateVariables(context, report)
   };
 };

tests/rules/assertions/spaceAfterTypeColon.js

@@ -1055,6 +1055,33 @@ const TYPE_CAST_EXPRESSIONS = {
   ]
 };
 
+const VARIABLE_EXPRESSIONS = {
+  invalid: [
+    {
+      code: 'const x:number = 7;',
+      errors: [{message: 'There must be a space after const type annotation colon.'}],
+      options: ['always'],
+      output: 'const x: number = 7;'
+    },
+    {
+      code: 'let x:number = 42;',
+      errors: [{message: 'There must be a space after let type annotation colon.'}],
+      options: ['always'],
+      output: 'let x: number = 42;'
+    }
+  ],
+  valid: [
+    {
+      code: 'const x: number = 7;',
+      options: ['always']
+    },
+    {
+      code: 'let x: number = 42;',
+      options: ['always']
+    }
+  ]
+};
+
 
 const ALL = [
   ARROW_FUNCTION_PARAMS,
@@ -1065,7 +1092,8 @@ const ALL = [
   CLASS_PROPERTIES,
   OBJECT_TYPE_PROPERTIES,
   OBJECT_TYPE_INDEXERS,
-  TYPE_CAST_EXPRESSIONS
+  TYPE_CAST_EXPRESSIONS,
+  VARIABLE_EXPRESSIONS
 ];
 
 export default {

tests/rules/assertions/spaceBeforeTypeColon.js

@@ -870,6 +870,33 @@ const TYPE_CAST_EXPRESSIONS = {
   ]
 };
 
+const VARIABLE_EXPRESSIONS = {
+  invalid: [
+    {
+      code: 'const x:number = 7;',
+      errors: [{message: 'There must be a space before const type annotation colon.'}],
+      options: ['always'],
+      output: 'const x :number = 7;'
+    },
+    {
+      code: 'let x:number = 42;',
+      errors: [{message: 'There must be a space before let type annotation colon.'}],
+      options: ['always'],
+      output: 'let x :number = 42;'
+    }
+  ],
+  valid: [
+    {
+      code: 'const x :number = 7;',
+      options: ['always']
+    },
+    {
+      code: 'let x :number = 42;',
+      options: ['always']
+    }
+  ]
+};
+
 const ALL = [
   ARROW_FUNCTION_PARAMS,
   ARROW_FUNCTION_RETURN,
@@ -879,7 +906,8 @@ const ALL = [
   CLASS_PROPERTIES,
   OBJECT_TYPE_PROPERTIES,
   OBJECT_TYPE_INDEXERS,
-  TYPE_CAST_EXPRESSIONS
+  TYPE_CAST_EXPRESSIONS,
+  VARIABLE_EXPRESSIONS
 ];
 
 export default {