Dec 14, 2024 · Dec 2, 2024 · Dec 2, 2024 · Dec 2, 2024 · Dec 2, 2024 · Dec 2, 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
  getParserServices,
  isTypeFlagSet,
  isUndefinedIdentifier,
  nullThrows,
  NullThrowsReasons,
 } from '../util';
 import { rangeToLoc } from '../util/rangeToLoc';

      );
    }

    function hasCommentsBetweenQuasi(
      startQuasi: TSESTree.TemplateElement,
      endQuasi: TSESTree.TemplateElement,
    ): boolean {
      const startToken = nullThrows(
        context.sourceCode.getTokenByRangeStart(startQuasi.range[0]),
        NullThrowsReasons.MissingToken('`${', 'opening template literal'),
      );
      const endToken = nullThrows(
        context.sourceCode.getTokenByRangeStart(endQuasi.range[0]),
        NullThrowsReasons.MissingToken('}', 'closing template literal'),
      );

      return context.sourceCode.commentsExistBetween(startToken, endToken);
    }

    return {
      TemplateLiteral(node: TSESTree.TemplateLiteral): void {
        if (node.parent.type === AST_NODE_TYPES.TaggedTemplateExpression) {
          isUnderlyingTypeString(node.expressions[0]);

        if (hasSingleStringVariable) {
          if (hasCommentsBetweenQuasi(node.quasis[0], node.quasis[1])) {
            return;
          }

          context.report({
            loc: rangeToLoc(context.sourceCode, [
              node.expressions[0].range[0] - 2,
            nextQuasi: node.quasis[index + 1],
            prevQuasi: node.quasis[index],
          }))
          .filter(({ expression, nextQuasi }) => {
          .filter(({ expression, nextQuasi, prevQuasi }) => {
            if (
              isUndefinedIdentifier(expression) ||
              isInfinityIdentifier(expression) ||
              return true;
            }

            // allow expressions that include comments
            if (hasCommentsBetweenQuasi(prevQuasi, nextQuasi)) {
              return false;
            }

            if (isLiteral(expression)) {
              // allow trailing whitespace literal
              if (startsWithNewLine(nextQuasi.value.raw)) {
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: [
      {
        line: 2,
        messageId: 'noUnnecessaryTemplateExpression',
      },
      {
        column: 2,
        endColumn: 2,
    ],
    output: [
      `
 \`use\${
  \`less\`
 }\`;
 \`u\${
  // hopefully this comment is not needed.
  'se'

 }le\${  \`ss\`  }\`;
      `,
      `
 \`useless\`;
 \`u\${
  // hopefully this comment is not needed.
  'se'

 }less\`;
      `,
    ],
  },
 \`trailing position interpolated empty string also makes whitespace clear    \${''}
 \`;
    `,
    `
 \`
 \${/* intentional comment before */ 'bar'}
 ...\`;
    `,
    `
 \`
 \${'bar' /* intentional comment after */}
 ...\`;
    `,
    `
 \`
 \${/* intentional comment before */ 'bar' /* intentional comment after */}
 ...\`;
    `,
    `
 \`\${/* intentional  before */ 'bar'}\`;
    `,
    `
 \`\${'bar' /* intentional comment after */}\`;
    `,
    `
 \`\${/* intentional comment before */ 'bar' /* intentional comment after */}\`;
    `,
    `
 \`\${
  // intentional comment before
  'bar'
 }\`;
    `,
    `
 \`\${
  'bar'
  // intentional comment after
 }\`;
    `,
  ],

  invalid: [
Original file line number	Diff line number	Diff line change
Expand Up		@@ -10,6 +10,8 @@ import {
		getParserServices,
		isTypeFlagSet,
		isUndefinedIdentifier,
		nullThrows,
		NullThrowsReasons,
		} from '../util';
		import { rangeToLoc } from '../util/rangeToLoc';

Expand DownExpand Up		@@ -92,6 +94,22 @@ export default createRule<[], MessageId>({
		);
		}

		function hasCommentsBetweenQuasi(
		startQuasi: TSESTree.TemplateElement,
		endQuasi: TSESTree.TemplateElement,
		): boolean {
		const startToken = nullThrows(
		context.sourceCode.getTokenByRangeStart(startQuasi.range[0]),
		NullThrowsReasons.MissingToken('`${', 'opening template literal'),
		);
		const endToken = nullThrows(
		context.sourceCode.getTokenByRangeStart(endQuasi.range[0]),
		NullThrowsReasons.MissingToken('}', 'closing template literal'),
		);

		return context.sourceCode.commentsExistBetween(startToken, endToken);
		}

		return {
		TemplateLiteral(node: TSESTree.TemplateLiteral): void {
		if (node.parent.type === AST_NODE_TYPES.TaggedTemplateExpression) {
Expand All		@@ -106,6 +124,10 @@ export default createRule<[], MessageId>({
		isUnderlyingTypeString(node.expressions[0]);

		if (hasSingleStringVariable) {
		if (hasCommentsBetweenQuasi(node.quasis[0], node.quasis[1])) {
		return;
		}

		context.report({
		loc: rangeToLoc(context.sourceCode, [
		node.expressions[0].range[0] - 2,
Expand All		@@ -132,7 +154,7 @@ export default createRule<[], MessageId>({
		nextQuasi: node.quasis[index + 1],
		prevQuasi: node.quasis[index],
		}))
		.filter(({ expression, nextQuasi }) => {
		.filter(({ expression, nextQuasi, prevQuasi }) => {
		if (
		isUndefinedIdentifier(expression) \|\|
		isInfinityIdentifier(expression) \|\|
Expand All		@@ -141,6 +163,11 @@ export default createRule<[], MessageId>({
		return true;
		}

		// allow expressions that include comments
		if (hasCommentsBetweenQuasi(prevQuasi, nextQuasi)) {
		return false;
		}

		if (isLiteral(expression)) {
		// allow trailing whitespace literal
		if (startsWithNewLine(nextQuasi.value.raw)) {
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -310,10 +310,6 @@ const invalidCases: readonly InvalidTestCase<
		}\`;
		`,
		errors: [
		{
		line: 2,
		messageId: 'noUnnecessaryTemplateExpression',
		},
		{
		column: 2,
		endColumn: 2,
Expand All		@@ -331,12 +327,18 @@ const invalidCases: readonly InvalidTestCase<
		],
		output: [
		`
		\`use\${
		\`less\`
		}\`;
		\`u\${
		// hopefully this comment is not needed.
		'se'

		}le\${ \`ss\` }\`;
		`,
		`
		\`useless\`;
		\`u\${
		// hopefully this comment is not needed.
		'se'

		}less\`;
		`,
		],
		},
Expand DownExpand Up		@@ -1104,6 +1106,42 @@ this code has trailing whitespace: \${' '}
		\`trailing position interpolated empty string also makes whitespace clear \${''}
		\`;
		`,
		`
		\`
		\${/* intentional comment before */ 'bar'}
		...\`;
		`,
		`
		\`
		\${'bar' /* intentional comment after */}
		...\`;
		`,
		`
		\`
		\${/* intentional comment before / 'bar' / intentional comment after */}
		...\`;
		`,
		`
		\`\${/* intentional before */ 'bar'}\`;
		`,
		`
		\`\${'bar' /* intentional comment after */}\`;
		`,
		`
		\`\${/* intentional comment before / 'bar' / intentional comment after */}\`;
		`,
		`
		\`\${
		// intentional comment before
		'bar'
		}\`;
		`,
		`
		\`\${
		'bar'
		// intentional comment after
		}\`;
		`,
		],

		invalid: [
Expand Down