fix(eslint-plugin): use bracket for infer type in array-type rule (#173)

Author: armano2

packages/eslint-plugin/lib/rules/array-type.js

@@ -67,6 +67,7 @@ function typeNeedsParentheses(node) {
     case 'TSFunctionType':
     case 'TSIntersectionType':
     case 'TSTypeOperator':
+    case 'TSInferType':
       return true;
     default:
       return false;

packages/eslint-plugin/tests/lib/rules/array-type.js

@@ -138,6 +138,11 @@ ruleTester.run('array-type', rule, {
 }`,
       options: ['array']
     },
+    {
+      // https://github.com/typescript-eslint/typescript-eslint/issues/172
+      code: 'type Unwrap<T> = T extends (infer E)[] ? E : T',
+      options: ['array']
+    },
     {
       code: `let z: Array = [3, "4"];`,
       options: ['generic']
@@ -173,6 +178,11 @@ ruleTester.run('array-type', rule, {
     {
       code: `type fooIntersection = Array<string & number>;`,
       options: ['generic']
+    },
+    {
+      // https://github.com/typescript-eslint/typescript-eslint/issues/172
+      code: 'type Unwrap<T> = T extends Array<infer E> ? E : T',
+      options: ['generic']
     }
   ],
   invalid: [
@@ -774,6 +784,34 @@ let yyyy: Arr<Array<Array<Arr<string>>>> = [[[["2"]]]];`,
           column: 19
         }
       ]
+    },
+    {
+      // https://github.com/typescript-eslint/typescript-eslint/issues/172
+      code: 'type Unwrap<T> = T extends Array<infer E> ? E : T',
+      output: 'type Unwrap<T> = T extends (infer E)[] ? E : T',
+      options: ['array'],
+      errors: [
+        {
+          messageId: 'errorStringArray',
+          data: { type: 'T' },
+          line: 1,
+          column: 28
+        }
+      ]
+    },
+    {
+      // https://github.com/typescript-eslint/typescript-eslint/issues/172
+      code: 'type Unwrap<T> = T extends (infer E)[] ? E : T',
+      output: 'type Unwrap<T> = T extends Array<infer E> ? E : T',
+      options: ['generic'],
+      errors: [
+        {
+          messageId: 'errorStringGeneric',
+          data: { type: 'T' },
+          line: 1,
+          column: 28
+        }
+      ]
     }
   ]
 });