fix(eslint-plugin): [no-type-alias] handle Template Literal Types

packages/eslint-plugin/docs/rules/no-type-alias.md

@@ -118,6 +118,8 @@ type Foo = string | string[];
 
 type Foo = string & string[];
 
+type Foo = `foo-${number}`;
+
 // reference types
 interface Bar {}
 class Baz implements Bar {}
@@ -139,6 +141,8 @@ type Foo = string;
 
 type Foo = string & string[];
 
+type Foo = `foo-${number}`;
+
 // reference types
 interface Bar {}
 class Baz implements Bar {}
@@ -156,6 +160,8 @@ type Foo = 'a' | 'b';
 
 type Foo = string | string[];
 
+type Foo = `a-${number}` | `b-${number}`;
+
 // reference types
 interface Bar {}
 class Baz implements Bar {}
@@ -175,6 +181,8 @@ type Foo = string;
 
 type Foo = string | string[];
 
+type Foo = `a-${number}` | `b-${number}`;
+
 // reference types
 interface Bar {}
 class Baz implements Bar {}
@@ -190,6 +198,8 @@ Examples of **correct** code for the `{ "allowAliases": "in-intersections" }` op
 // primitives
 type Foo = string & string[];
 
+type Foo = `a-${number}` & `b-${number}`;
+
 // reference types
 interface Bar {}
 class Baz implements Bar {}
@@ -205,6 +215,8 @@ type Foo = 'a';
 
 type Foo = string;
 
+type Foo = `foo-${number}`;
+
 // reference types
 interface Bar {}
 class Baz implements Bar {}
@@ -222,6 +234,10 @@ type Foo = string | string[];
 
 type Foo = string & string[];
 
+type Foo = `a-${number}` & `b-${number}`;
+
+type Foo = `a-${number}` | `b-${number}`;
+
 // reference types
 interface Bar {}
 class Baz implements Bar {}

packages/eslint-plugin/src/rules/no-type-alias.ts

@@ -133,6 +133,7 @@ export default util.createRule<Options, MessageIds>({
       AST_NODE_TYPES.TSLiteralType,
       AST_NODE_TYPES.TSTypeQuery,
       AST_NODE_TYPES.TSIndexedAccessType,
+      AST_NODE_TYPES.TSTemplateLiteralType,
     ]);
 
     /**

packages/eslint-plugin/tests/rules/no-type-alias.test.ts

@@ -131,6 +131,66 @@ ruleTester.run('no-type-alias', rule, {
       code: 'type Foo = 1 | (2 & 3);',
       options: [{ allowAliases: 'in-unions-and-intersections' }],
     },
+    {
+      code: 'type Foo = `a-${number}`;',
+      options: [{ allowAliases: 'always' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | `b-${number}`;',
+      options: [{ allowAliases: 'always' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | `b-${number}`;',
+      options: [{ allowAliases: 'in-unions-and-intersections' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | `b-${number}`;',
+      options: [{ allowAliases: 'in-unions' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | `b-${number}` | `c-${number}`;',
+      options: [{ allowAliases: 'always' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | `b-${number}` | `c-${number}`;',
+      options: [{ allowAliases: 'in-unions-and-intersections' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | `b-${number}` | `c-${number}`;',
+      options: [{ allowAliases: 'in-unions' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` & `b-${number}`;',
+      options: [{ allowAliases: 'always' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` & `b-${number}`;',
+      options: [{ allowAliases: 'in-unions-and-intersections' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` & `b-${number}`;',
+      options: [{ allowAliases: 'in-intersections' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` & `b-${number}` & `c-${number}`;',
+      options: [{ allowAliases: 'always' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` & `b-${number}` & `c-${number}`;',
+      options: [{ allowAliases: 'in-unions-and-intersections' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` & `b-${number}` & `c-${number}`;',
+      options: [{ allowAliases: 'in-intersections' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | (`b-${number}` & `c-${number}`);',
+      options: [{ allowAliases: 'always' }],
+    },
+    {
+      code: 'type Foo = `a-${number}` | (`b-${number}` & `c-${number}`);',
+      options: [{ allowAliases: 'in-unions-and-intersections' }],
+    },
     {
       code: 'type Foo = true;',
       options: [{ allowAliases: 'always' }],
@@ -3340,5 +3400,66 @@ type Foo<T> = {
         },
       ],
     },
+    {
+      code: 'type Foo = `foo-${number}`;',
+      errors: [
+        {
+          messageId: 'noTypeAlias',
+          data: {
+            alias: 'aliases',
+          },
+          line: 1,
+          column: 12,
+        },
+      ],
+    },
+    {
+      code: 'type Foo = `a-${number}` | `b-${number}`;',
+      options: [{ allowAliases: 'never' }],
+      errors: [
+        {
+          messageId: 'noCompositionAlias',
+          data: {
+            typeName: 'Aliases',
+            compositionType: 'union',
+          },
+          line: 1,
+          column: 12,
+        },
+        {
+          messageId: 'noCompositionAlias',
+          data: {
+            typeName: 'Aliases',
+            compositionType: 'union',
+          },
+          line: 1,
+          column: 28,
+        },
+      ],
+    },
+    {
+      code: 'type Foo = `a-${number}` & `b-${number}`;',
+      options: [{ allowAliases: 'never' }],
+      errors: [
+        {
+          messageId: 'noCompositionAlias',
+          data: {
+            typeName: 'Aliases',
+            compositionType: 'intersection',
+          },
+          line: 1,
+          column: 12,
+        },
+        {
+          messageId: 'noCompositionAlias',
+          data: {
+            typeName: 'Aliases',
+            compositionType: 'intersection',
+          },
+          line: 1,
+          column: 28,
+        },
+      ],
+    },
   ],
 });