From b7ad4ffba9fe37de0240f75e74e6a007402076d1 Mon Sep 17 00:00:00 2001
From: YeonJuan <yeonjuan93@naver.com>
Date: Tue, 4 Feb 2025 20:59:05 +0900
Subject: [PATCH] fix(eslint-plugin): [no-unnecessary-template-expression]
 ignore enum and enum mebers

---
 .../no-unnecessary-template-expression.mdx    |  1 +
 .../no-unnecessary-template-expression.ts     | 20 +++--
 .../no-unnecessary-template-expression.shot   |  1 +
 ...no-unnecessary-template-expression.test.ts | 79 +++++++++++++------
 4 files changed, 65 insertions(+), 36 deletions(-)

diff --git a/packages/eslint-plugin/docs/rules/no-unnecessary-template-expression.mdx b/packages/eslint-plugin/docs/rules/no-unnecessary-template-expression.mdx
index 9262d9fea9be..aded1f4b85a0 100644
--- a/packages/eslint-plugin/docs/rules/no-unnecessary-template-expression.mdx
+++ b/packages/eslint-plugin/docs/rules/no-unnecessary-template-expression.mdx
@@ -66,6 +66,7 @@ enum ABC {
   C = 'C',
 }
 type ABCUnion = `${ABC}`;
+type A = `${ABC.A}`;
 
 // Interpolating type parameters is allowed.
 type TextUtil<T extends string> = `${T}`;
diff --git a/packages/eslint-plugin/src/rules/no-unnecessary-template-expression.ts b/packages/eslint-plugin/src/rules/no-unnecessary-template-expression.ts
index 842f549eb34a..6c70e134043e 100644
--- a/packages/eslint-plugin/src/rules/no-unnecessary-template-expression.ts
+++ b/packages/eslint-plugin/src/rules/no-unnecessary-template-expression.ts
@@ -1,6 +1,7 @@
 import type { TSESLint } from '@typescript-eslint/utils';
 
 import { TSESTree, AST_NODE_TYPES } from '@typescript-eslint/utils';
+import * as tsutils from 'ts-api-utils';
 import * as ts from 'typescript';
 
 import {
@@ -76,16 +77,13 @@ export default createRule<[], MessageId>({
       return isStringLike(type);
     }
 
-    /**
-     * Checks for whole enum types, i.e. `MyEnum`, and not their values, i.e. `MyEnum.A`
-     */
-    function isEnumType(type: ts.Type): boolean {
-      const symbol = type.getSymbol();
-
-      return !!(
-        symbol?.valueDeclaration &&
-        ts.isEnumDeclaration(symbol.valueDeclaration)
-      );
+    function isEnumMemberType(type: ts.Type): boolean {
+      return tsutils.typeParts(type).some(t => {
+        const symbol = t.getSymbol();
+        return !!(
+          symbol?.valueDeclaration && ts.isEnumMember(symbol.valueDeclaration)
+        );
+      });
     }
 
     const isLiteral = isNodeOfType(TSESTree.AST_NODE_TYPES.Literal);
@@ -460,7 +458,7 @@ export default createRule<[], MessageId>({
             constraintType &&
             !isTypeParameter &&
             isUnderlyingTypeString(constraintType) &&
-            !isEnumType(constraintType)
+            !isEnumMemberType(constraintType)
           ) {
             reportSingleInterpolation(node);
             return;
diff --git a/packages/eslint-plugin/tests/docs-eslint-output-snapshots/no-unnecessary-template-expression.shot b/packages/eslint-plugin/tests/docs-eslint-output-snapshots/no-unnecessary-template-expression.shot
index 2d5241b52e5e..b4662d8bdcfd 100644
--- a/packages/eslint-plugin/tests/docs-eslint-output-snapshots/no-unnecessary-template-expression.shot
+++ b/packages/eslint-plugin/tests/docs-eslint-output-snapshots/no-unnecessary-template-expression.shot
@@ -59,6 +59,7 @@ enum ABC {
   C = 'C',
 }
 type ABCUnion = \`\${ABC}\`;
+type A = \`\${ABC.A}\`;
 
 // Interpolating type parameters is allowed.
 type TextUtil<T extends string> = \`\${T}\`;
diff --git a/packages/eslint-plugin/tests/rules/no-unnecessary-template-expression.test.ts b/packages/eslint-plugin/tests/rules/no-unnecessary-template-expression.test.ts
index f60f87126f78..191cfeeb0de7 100644
--- a/packages/eslint-plugin/tests/rules/no-unnecessary-template-expression.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-unnecessary-template-expression.test.ts
@@ -1188,6 +1188,60 @@ enum Foo {
   A = 1,
   B = 2,
 }
+type Bar = \`\${Foo.A}\`;
+    `,
+    `
+enum Enum1 {
+  A = 'A1',
+  B = 'B1',
+}
+
+enum Enum2 {
+  A = 'A2',
+  B = 'B2',
+}
+
+type Union = \`\${Enum1 | Enum2}\`;
+    `,
+    `
+enum Enum1 {
+  A = 'A1',
+  B = 'B1',
+}
+
+enum Enum2 {
+  A = 'A2',
+  B = 'B2',
+}
+
+type Union = \`\${Enum1.A | Enum2.B}\`;
+    `,
+    `
+enum Enum1 {
+  A = 'A1',
+  B = 'B1',
+}
+
+enum Enum2 {
+  A = 'A2',
+  B = 'B2',
+}
+type Enums = Enum1 | Enum2;
+type Union = \`\${Enums}\`;
+    `,
+    `
+enum Enum {
+  A = 'A',
+  B = 'A',
+}
+
+type Intersection = \`\${Enum1.A & string}\`;
+    `,
+    `
+enum Foo {
+  A = 'A',
+  B = 'B',
+}
 type Bar = \`\${Foo.A}\`;
     `,
     `
@@ -1412,30 +1466,5 @@ type Bar = Foo;
       ],
       output: "type FooBar = 'foo' | 'bar';",
     },
-    {
-      code: `
-enum Foo {
-  A = 'A',
-  B = 'B',
-}
-type Bar = \`\${Foo.A}\`;
-      `,
-      errors: [
-        {
-          column: 13,
-          endColumn: 21,
-          endLine: 6,
-          line: 6,
-          messageId: 'noUnnecessaryTemplateExpression',
-        },
-      ],
-      output: `
-enum Foo {
-  A = 'A',
-  B = 'B',
-}
-type Bar = Foo.A;
-      `,
-    },
   ],
 });

<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>
<html xmlns='http://www.w3.org/1999/xhtml'>
<head>
<title>pFad - Phonifier reborn</title>
<meta http-equiv='Content-Type' content='text/html; charset=utf-8' />
</head>
<body>
<h1>Pfad - The Proxy pFad of &#169; 2024 Garber Painting. All rights reserved.</h1>


<!-- Disclaimer -->
<p>Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.</p>
<br>
<p>Alternative Proxies:</p><p><a href="http://rainy.clevelandohioweatherforecast.com/php-proxy/index.php?q=https://patch-diff.githubusercontent.com/raw/typescript-eslint/typescript-eslint/pull/10782.patch" target="_blank">Alternative Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/index.php?u=https://patch-diff.githubusercontent.com/raw/typescript-eslint/typescript-eslint/pull/10782.patch" target="_blank">pFad Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v3index.php?u=https://patch-diff.githubusercontent.com/raw/typescript-eslint/typescript-eslint/pull/10782.patch" target="_blank">pFad v3 Proxy</a></p><p><a href="http://rainy.clevelandohioweatherforecast.com/pFad/v4index.php?u=https://patch-diff.githubusercontent.com/raw/typescript-eslint/typescript-eslint/pull/10782.patch" target="_blank">pFad v4 Proxy</a></p></body>
</html>