Nov 26, 2024 · Nov 20, 2024 · Nov 20, 2024 · Nov 20, 2024 · Nov 20, 2024 · Nov 20, 2024
diff --git a/packages/eslint-plugin/src/rules/no-unnecessary-template-expression.ts b/packages/eslint-plugin/src/rules/no-unnecessary-template-expression.ts
          return;
        }

        const fixableExpressions = node.expressions
          .filter(
            expression =>
              isLiteral(expression) ||
              isTemplateLiteral(expression) ||
        const fixableExpressionsReversed = node.expressions
          .map((expression, index) => ({
            expression,
            nextQuasi: node.quasis[index + 1],
            prevQuasi: node.quasis[index],
          }))
          .filter(({ expression, nextQuasi }) => {
            if (
              isUndefinedIdentifier(expression) ||
              isInfinityIdentifier(expression) ||
              isNaNIdentifier(expression),
          )
              isNaNIdentifier(expression)
            ) {
              return true;
            }

            if (isLiteral(expression)) {
              // allow trailing whitespace literal
              if (startsWithNewLine(nextQuasi.value.raw)) {
                return !(
                  typeof expression.value === 'string' &&
                  isWhitespace(expression.value)
                );
              }
              return true;
            }

            if (isTemplateLiteral(expression)) {
              // allow trailing whitespace literal
              if (startsWithNewLine(nextQuasi.value.raw)) {
                return !(
                  expression.quasis.length === 1 &&
                  isWhitespace(expression.quasis[0].value.raw)
                );
              }
              return true;
            }

            return false;
          })
          .reverse();

        let nextCharacterIsOpeningCurlyBrace = false;

        for (const expression of fixableExpressions) {
        for (const {
          expression,
          nextQuasi,
          prevQuasi,
        } of fixableExpressionsReversed) {
          const fixers: ((fixer: TSESLint.RuleFixer) => TSESLint.RuleFix[])[] =
            [];
          const index = node.expressions.indexOf(expression);
          const prevQuasi = node.quasis[index];
          const nextQuasi = node.quasis[index + 1];

          if (nextQuasi.value.raw.length !==0) {
          if (nextQuasi.value.raw !=='') {
            nextCharacterIsOpeningCurlyBrace =
              nextQuasi.value.raw.startsWith('{');
          }
    };
  },
 });

 function isWhitespace(x: string): boolean {
  // allow empty string too since we went to allow
  // `      ${''}
  // `;
  //
  // in addition to
  // `${'        '}
  // `;
  //
  return /^\s*$/.test(x);
 }

 function startsWithNewLine(x: string): boolean {
  return x.startsWith('\n') || x.startsWith('\r\n');
 }
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
    errors: [{ messageId: 'noUnnecessaryTemplateExpression' }],
    output: '` \\ud83d\\udc68 `;',
  },
  {
    code: `
 \`
 this code does not have trailing whitespace: \${' '}\\n even though it might look it.\`;
    `,
    errors: [
      {
        messageId: 'noUnnecessaryTemplateExpression',
      },
    ],
    output: `
 \`
 this code does not have trailing whitespace:  \\n even though it might look it.\`;
    `,
  },
  {
    code: `
 \`
 this code has trailing position template expression \${'but it isn\\'t whitespace'}
    \`;
    `,
    errors: [
      {
        messageId: 'noUnnecessaryTemplateExpression',
      },
    ],
    output: `
 \`
 this code has trailing position template expression but it isn\\'t whitespace
    \`;
    `,
  },
  {
    code: noFormat`
 \`trailing whitespace followed by escaped windows newline: \${' '}\\r\\n\`;
    `,
    errors: [
      {
        messageId: 'noUnnecessaryTemplateExpression',
      },
    ],
    output: `
 \`trailing whitespace followed by escaped windows newline:  \\r\\n\`;
    `,
  },
  {
    code: `
 \`template literal with interpolations followed by newline: \${\` \${'interpolation'} \`}
 \`;
    `,
    errors: [
      {
        messageId: 'noUnnecessaryTemplateExpression',
      },
      {
        messageId: 'noUnnecessaryTemplateExpression',
      },
    ],
    output: [
      `
 \`template literal with interpolations followed by newline:  \${'interpolation'}${' '}
 \`;
    `,
      `
 \`template literal with interpolations followed by newline:  interpolation${' '}
 \`;
    `,
    ],
  },
 ];

 describe('fixer should not change runtime value', () => {
    `
 \`not a useless \${String.raw\`nested interpolation \${a}\`}\`;
    `,
    `
 \`
 this code has trailing whitespace: \${'    '}
    \`;
    `,
    noFormat`
 \`this code has trailing whitespace with a windows \\\r new line: \${' '}\r\n\`;
    `,
    `
 \`trailing position interpolated empty string also makes whitespace clear    \${''}
 \`;
    `,
  ],

  invalid: [
diff --git a/packages/eslint-plugin/tests/rules/no-useless-constructor.test.ts b/packages/eslint-plugin/tests/rules/no-useless-constructor.test.ts
    `,
  ],
  invalid: [
    /* eslint-disable @typescript-eslint/no-unnecessary-template-expression -- trailing whitespace */

    {
      code: `
 class A {
        },
      ],
    },
    /* eslint-enable @typescript-eslint/no-unnecessary-template-expression */
  ],
 });
Original file line number	Diff line number	Diff line change
Expand Up		@@ -126,27 +126,58 @@ export default createRule<[], MessageId>({
		return;
		}

		const fixableExpressions = node.expressions
		.filter(
		expression =>
		isLiteral(expression) \|\|
		isTemplateLiteral(expression) \|\|
		const fixableExpressionsReversed = node.expressions
		.map((expression, index) => ({
		expression,
		nextQuasi: node.quasis[index + 1],
		prevQuasi: node.quasis[index],
		}))
		.filter(({ expression, nextQuasi }) => {
		if (
		isUndefinedIdentifier(expression) \|\|
		isInfinityIdentifier(expression) \|\|
		isNaNIdentifier(expression),
		)
		isNaNIdentifier(expression)
		) {
		return true;
		}

		if (isLiteral(expression)) {
		// allow trailing whitespace literal
		if (startsWithNewLine(nextQuasi.value.raw)) {
		return !(
		typeof expression.value === 'string' &&
		isWhitespace(expression.value)
		);
		}
		return true;
		}

		if (isTemplateLiteral(expression)) {
		// allow trailing whitespace literal
		if (startsWithNewLine(nextQuasi.value.raw)) {
		return !(
		expression.quasis.length === 1 &&
		isWhitespace(expression.quasis[0].value.raw)
		);
		}
		return true;
		}

		return false;
		})
		.reverse();

		let nextCharacterIsOpeningCurlyBrace = false;

		for (const expression of fixableExpressions) {
		for (const {
		expression,
		nextQuasi,
		prevQuasi,
		} of fixableExpressionsReversed) {
		const fixers: ((fixer: TSESLint.RuleFixer) => TSESLint.RuleFix[])[] =
		[];
		const index = node.expressions.indexOf(expression);
		const prevQuasi = node.quasis[index];
		const nextQuasi = node.quasis[index + 1];

		if (nextQuasi.value.raw.length !==0) {
		if (nextQuasi.value.raw !=='') {
		nextCharacterIsOpeningCurlyBrace =
		nextQuasi.value.raw.startsWith('{');
		}
Expand DownExpand Up		@@ -271,3 +302,19 @@ export default createRule<[], MessageId>({
		};
		},
		});

		function isWhitespace(x: string): boolean {
		// allow empty string too since we went to allow
		// ` ${''}
		// `;
		//
		// in addition to
		// `${' '}
		// `;
		//
		return /^\s*$/.test(x);
		}

		function startsWithNewLine(x: string): boolean {
		return x.startsWith('\n') \|\| x.startsWith('\r\n');
		}
Original file line number	Diff line number	Diff line change
Expand Up		@@ -885,6 +885,75 @@ const invalidCases: readonly InvalidTestCase<
		errors: [{ messageId: 'noUnnecessaryTemplateExpression' }],
		output: '` \\ud83d\\udc68 `;',
		},
		{
		code: `
		\`
		this code does not have trailing whitespace: \${' '}\\n even though it might look it.\`;
		`,
		errors: [
		{
		messageId: 'noUnnecessaryTemplateExpression',
		},
		],
		output: `
		\`
		this code does not have trailing whitespace: \\n even though it might look it.\`;
		`,
		},
		{
		code: `
		\`
		this code has trailing position template expression \${'but it isn\\'t whitespace'}
		\`;
		`,
		errors: [
		{
		messageId: 'noUnnecessaryTemplateExpression',
		},
		],
		output: `
		\`
		this code has trailing position template expression but it isn\\'t whitespace
		\`;
		`,
		},
		{
		code: noFormat`
		\`trailing whitespace followed by escaped windows newline: \${' '}\\r\\n\`;
		`,
		errors: [
		{
		messageId: 'noUnnecessaryTemplateExpression',
		},
		],
		output: `
		\`trailing whitespace followed by escaped windows newline: \\r\\n\`;
		`,
		},
		{
		code: `
		\`template literal with interpolations followed by newline: \${\` \${'interpolation'} \`}
		\`;
		`,
		errors: [
		{
		messageId: 'noUnnecessaryTemplateExpression',
		},
		{
		messageId: 'noUnnecessaryTemplateExpression',
		},
		],
		output: [
		`
		\`template literal with interpolations followed by newline: \${'interpolation'}${' '}
		\`;
		`,
		`
		\`template literal with interpolations followed by newline: interpolation${' '}
		\`;
		`,
		],
		},
		];

		describe('fixer should not change runtime value', () => {
Expand DownExpand Up		@@ -1023,6 +1092,18 @@ ruleTester.run('no-unnecessary-template-expression', rule, {
		`
		\`not a useless \${String.raw\`nested interpolation \${a}\`}\`;
		`,
		`
		\`
		this code has trailing whitespace: \${' '}
		\`;
		`,
		noFormat`
		\`this code has trailing whitespace with a windows \\\r new line: \${' '}\r\n\`;
		`,
		`
		\`trailing position interpolated empty string also makes whitespace clear \${''}
		\`;
		`,
		],

		invalid: [
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -209,8 +209,6 @@ class A extends Object {
		`,
		],
		invalid: [
		/* eslint-disable @typescript-eslint/no-unnecessary-template-expression -- trailing whitespace */
Copy link MemberAuthor kirkwaiblingerNov 20, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. 🙂 JoshuaKGoldberg reacted with laugh emoji

		{
		code: `
		class A {
Expand DownExpand Up		@@ -432,6 +430,5 @@ ${' '}
		},
		],
		},
		/* eslint-enable @typescript-eslint/no-unnecessary-template-expression */
		],
		});