als-remove-js-comments/test.js

A utility for removing JavaScript comments, supporting both single-line and multi-line comments with proper handling of string literals.

const { describe, it } = require('node:test');
const assert = require('node:assert');
const removeComments = require('./remove-comments');

describe('removeComments', () => {
   it('should remove single-line comments', () => {
      const input = `const a = 5; // This is a comment\nconst b = 10; // Another comment`;
      const expectedOutput = `const a = 5; \nconst b = 10; `;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should remove multi-line comments', () => {
      const input = `const a = 5; /* This is a\nmulti-line comment */\nconst b = 10;`;
      const expectedOutput = `const a = 5; \nconst b = 10;`;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should handle comments on separate lines', () => {
      const input = `// This is a comment\nconst a = 5;`;
      const expectedOutput = `\nconst a = 5;`;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should handle strings with escaped quotes', () => {
      const input = `const str = "This is a string with an escaped quote: \\" and a // comment";`;
      assert.strictEqual(removeComments(input), input);
   });

   it('should handle empty strings', () => {
      const input = ``;
      const expectedOutput = ``;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should handle code without comments', () => {
      const input = `const a = 5;\nconst b = 10;`;
      const expectedOutput = `const a = 5;\nconst b = 10;`;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should remove mixed single-line and multi-line comments', () => {
      const input = `const a = 5; // single-line\n/* multi-line\ncomment */ const b = 10;`;
      const expectedOutput = `const a = 5; \n const b = 10;`;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should remove single-line comment with // inside quotes', () => {
      const input = `ic.outerHTML = ic.outerHTML + '<svg version="1.1" id="iconBigCursorSvg" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 512 512" style="position: absolute;width: 19px;height: 19px;top: 9px; left: 9px;" xml:space="preserve"><path d="M 423.547 323.115 l -320 -320 c -3.051 -3.051 -7.637 -3.947 -11.627 -2.304 s -6.592 5.547 -6.592 9.856 V 480 c 0 4.501 2.837 8.533 7.083 10.048 c 4.224 1.536 8.981 0.192 11.84 -3.285 l 85.205 -104.128 l 56.853 123.179 c 1.792 3.883 5.653 6.187 9.685 6.187 c 1.408 0 2.837 -0.277 4.203 -0.875 l 74.667 -32 c 2.645 -1.131 4.736 -3.285 5.76 -5.973 c 1.024 -2.688 0.939 -5.675 -0.277 -8.299 l -57.024 -123.52 h 132.672 c 4.309 0 8.213 -2.603 9.856 -6.592 C 427.515 330.752 426.598 326.187 423.547 323.115 Z"/></svg>';`;
      assert.strictEqual(removeComments(input), input);
   });
});

describe('removeComments - Additional Tests', () => {
   it('should remove multiline comments that are not properly closed', () => {
      const input = `const a = 5; /* unclosed comment`;
      const expectedOutput = `const a = 5; `;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should not remove URLs containing // or /* */', () => {
      const input = `const url = 'http://example.com/*not-a-comment*/';`;
      assert.strictEqual(removeComments(input), input);
   });

   it('should handle JSX inline attributes', () => {
      const input = `
       const Button = () => (
           <button title="Click me // not a comment">
               {/* Click here */}
               Click Me
           </button>
       );`;
      const expectedOutput = `
       const Button = () => (
           <button title="Click me // not a comment">
               
               Click Me
           </button>
       );`;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should remove comments after JSX components', () => {
      const input = `
       <div>
           <Component /> // comment after component
       </div>`;
      const expectedOutput = `
       <div>
           <Component /> 
       </div>`;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

   it('should preserve comments inside strings', () => {
      const input = `const str = "This is a string with /* not a comment */ inside";`;
      assert.strictEqual(removeComments(input), input);
   });

   it('should handle JSX with comments', () => {
      const input = `
   const App = () => {
       return (
           <div>
               {/* This is a JSX comment */}
               Hello World!
           </div>
       );
   };`;
      const expectedOutput = `
   const App = () => {
       return (
           <div>
               
               Hello World!
           </div>
       );
   };`;

      const result = removeComments(input)
      assert.strictEqual(result, expectedOutput);
   });

   it.skip('should handle nested comments gracefully', () => {
      const input = `const a = 5; /* outer /* inner */ still outer */ const b = 10;`;
      const expectedOutput = `const a = 5;  const b = 10;`;
      assert.strictEqual(removeComments(input), expectedOutput);
   });

});