refactor: modify code and tests

typescript-eslint · Mar 6, 2024 · 67c097e · 67c097e
1 parent a259377
commit 67c097e
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Showing 2 changed files with 88 additions and 29 deletions.
diff --git a/packages/eslint-plugin/src/rules/no-useless-template-literals.ts b/packages/eslint-plugin/src/rules/no-useless-template-literals.ts
@@ -54,12 +54,11 @@ export default createRule<[], MessageId>({
     }
 
     function isLiteral(expression: TSESTree.Expression): boolean {
-      return (
-        expression.type === AST_NODE_TYPES.Literal ||
-        (expression.type === AST_NODE_TYPES.TemplateLiteral &&
-          expression.expressions.length === 0 &&
-          expression.quasis.length === 1)
-      );
+      return expression.type === AST_NODE_TYPES.Literal;
+    }
+
+    function isTemplateLiteral(expression: TSESTree.Expression): boolean {
+      return expression.type === AST_NODE_TYPES.TemplateLiteral;
     }
 
     function isInfinityIdentifier(expression: TSESTree.Expression): boolean {
@@ -115,13 +114,9 @@ export default createRule<[], MessageId>({
         }
 
         const fixableExpressions = node.expressions.filter(
-          (
-            expression,
-          ): expression is
-            | TSESTree.Literal
-            | TSESTree.TemplateLiteral
-            | TSESTree.Identifier =>
+          expression =>
             isLiteral(expression) ||
+            isTemplateLiteral(expression) ||
             isUndefinedIdentifier(expression) ||
             isInfinityIdentifier(expression) ||
             isNaNIdentifier(expression),
@@ -155,6 +150,19 @@ export default createRule<[], MessageId>({
                 const escapedValue = stringValue.replace(/([`$\\])/g, '\\$1');
 
                 fixes.push(fixer.replaceText(expression, escapedValue));
+              } else if (isTemplateLiteral(expression)) {
+                // Note that some template literals get handled in the previous branch too.
+                // Remove the beginning and trailing backtick characters.
+                fixes.push(
+                  fixer.removeRange([
+                    expression.range[0],
+                    expression.range[0] + 1,
+                  ]),
+                  fixer.removeRange([
+                    expression.range[1] - 1,
+                    expression.range[1],
+                  ]),
+                );
               }
 
               return fixes;

diff --git a/packages/eslint-plugin/tests/rules/no-useless-template-literals.test.ts b/packages/eslint-plugin/tests/rules/no-useless-template-literals.test.ts
@@ -61,11 +61,6 @@ ruleTester.run('no-useless-template-literals', rule, {
       \`\${left}\${center}\${right}\`;
     `,
 
-    `
-      declare const num: 1;
-      \`a\${\`b\${num}\`}c\`;
-    `,
-
     '`1 + 1 = ${1 + 1}`;',
 
     '`true && false = ${true && false}`;',
@@ -136,6 +131,10 @@ ruleTester.run('no-useless-template-literals', rule, {
     noFormat`
       \`with windows \r new line\`;
     `,
+
+    `
+\`not a useless \${String.raw\`nested interpolation \${a}\`}\`;
+    `,
   ],
 
   invalid: [
@@ -363,39 +362,91 @@ ruleTester.run('no-useless-template-literals', rule, {
     },
 
     {
-      code: "`a${'b'}`;",
-      output: '`ab`;',
+      code: "`use${'less'}`;",
+      output: '`useless`;',
       errors: [
         {
           messageId: 'noUselessTemplateLiteral',
           line: 1,
-          column: 5,
-          endColumn: 8,
         },
       ],
     },
 
     {
-      code: '`a${`${`b`}c`}`;',
-      output: '`a${`bc`}`;',
+      code: '`use${`less`}`;',
+      output: '`useless`;',
       errors: [
         {
           messageId: 'noUselessTemplateLiteral',
           line: 1,
-          column: 8,
-          endColumn: 11,
         },
       ],
     },
 
     {
-      code: '`a${`bc`}`;',
-      output: '`abc`;',
+      code: `
+declare const nested: string, interpolation: string;
+\`use\${\`less\${nested}\${interpolation}\`}\`;
+      `,
+      output: `
+declare const nested: string, interpolation: string;
+\`useless\${nested}\${interpolation}\`;
+      `,
       errors: [
         {
           messageId: 'noUselessTemplateLiteral',
-          line: 1,
-          column: 5,
+        },
+      ],
+    },
+
+    {
+      code: noFormat`
+\`u\${
+  // hopefully this comment is not needed.
+  'se'
+
+}\${
+  \`le\${  \`ss\`  }\`
+}\`;
+      `,
+      output: `
+\`use\${
+  \`less\`
+}\`;
+      `,
+      errors: [
+        {
+          messageId: 'noUselessTemplateLiteral',
+          line: 4,
+        },
+        {
+          messageId: 'noUselessTemplateLiteral',
+          line: 7,
+          column: 3,
+          endLine: 7,
+        },
+        {
+          messageId: 'noUselessTemplateLiteral',
+          line: 7,
+          column: 10,
+          endLine: 7,
+        },
+      ],
+    },
+    {
+      code: noFormat`
+\`use\${
+  \`less\`
+}\`;
+      `,
+      output: `
+\`useless\`;
+      `,
+      errors: [
+        {
+          messageId: 'noUselessTemplateLiteral',
+          line: 3,
+          column: 3,
           endColumn: 9,
         },
       ],