feat: add support for template literals

Author: som-sm

rules/prefer-string-raw.js

@@ -8,27 +8,9 @@ const messages = {
 
 const BACKSLASH = '\\';
 
-function unescapeBackslash(raw) {
-	const quote = raw.charAt(0);
-
-	raw = raw.slice(1, -1);
-
-	let result = '';
-	for (let position = 0; position < raw.length; position++) {
-		const character = raw[position];
-		if (character === BACKSLASH) {
-			const nextCharacter = raw[position + 1];
-			if (nextCharacter === BACKSLASH || nextCharacter === quote) {
-				result += nextCharacter;
-				position++;
-				continue;
-			}
-		}
-
-		result += character;
-	}
-
-	return result;
+function unescapeBackslash(value, quote = '') {
+	return value
+		.replaceAll(new RegExp(String.raw`\\([\\${quote}])`, 'g'), '$1');
 }
 
 /** @param {import('eslint').Rule.RuleContext} context */
@@ -65,7 +47,7 @@ const create = context => {
 			return;
 		}
 
-		const unescaped = unescapeBackslash(raw);
+		const unescaped = unescapeBackslash(raw.slice(1, -1), raw.charAt(0));
 		if (unescaped !== node.value) {
 			return;
 		}
@@ -79,6 +61,52 @@ const create = context => {
 			},
 		};
 	});
+
+	context.on('TemplateLiteral', node => {
+		if (node.parent.type === 'TaggedTemplateExpression') {
+			return;
+		}
+
+		let suggestedValue = '';
+		let hasBackslash = false;
+
+		for (let index = 0; index < node.quasis.length; index++) {
+			const quasi = node.quasis[index];
+			const {raw, cooked} = quasi.value;
+
+			if (cooked.at(-1) === BACKSLASH) {
+				return;
+			}
+
+			const unescaped = unescapeBackslash(raw);
+			if (unescaped !== cooked) {
+				return;
+			}
+
+			if (cooked.includes(BACKSLASH)) {
+				hasBackslash = true;
+			}
+
+			if (index > 0) {
+				suggestedValue += '${' + context.sourceCode.getText(node.expressions[index - 1]) + '}';
+			}
+
+			suggestedValue += unescaped;
+		}
+
+		if (!hasBackslash) {
+			return;
+		}
+
+		return {
+			node,
+			messageId: MESSAGE_ID,
+			* fix(fixer) {
+				yield fixer.replaceText(node, `String.raw\`${suggestedValue}\``);
+				yield * fixSpaceAroundKeyword(fixer, node, context.sourceCode);
+			},
+		};
+	});
 };
 
 /** @type {import('eslint').Rule.RuleModule} */

test/prefer-string-raw.js

@@ -1,3 +1,4 @@
+/* eslint-disable no-template-curly-in-string */
 import outdent from 'outdent';
 import {getTester} from './utils/test.js';
 
@@ -18,7 +19,6 @@ test.snapshot({
 		`,
 		String.raw`a = 'a\\b\u{51}c'`,
 		'a = "a\\\\b`"',
-		// eslint-disable-next-line no-template-curly-in-string
 		'a = "a\\\\b${foo}"',
 		{
 			code: String.raw`<Component attribute="a\\b" />`,
@@ -43,6 +43,32 @@ test.snapshot({
 	],
 });
 
+test.snapshot({
+	valid: [
+		'a = `a`',
+		'a = `${foo}`',
+		'a = `a\\tb`',
+		'a = `a\\``',
+		'a = `a\\${`',
+		'a = `a\\\\b\\\'`',
+		'a = `a\\\\b\\"`',
+		'a = `\\\\`',
+		'a = `a${foo}b`',
+		'a = `a\\\\b${foo}a\\tb`',
+		outdent`
+			a = \`\\\\a \\
+			b\`
+		`,
+	],
+	invalid: [
+		'a = `a\\\\b`',
+		'a = `a\\\\b${foo}cd`',
+		'a = `a\\\\b${foo}cd${foo.bar}e\\\\f`',
+		'a = `b${foo}${foo.bar}a\\\\b`',
+		'a = `a\\\\b${"c\\\\d"}e`',
+	],
+});
+
 test.typescript({
 	valid: [
 		outdent`

test/snapshots/prefer-string-raw.js.md

@@ -87,3 +87,115 @@ Generated by [AVA](https://avajs.dev).
     > 1 | const foo = "foo \\\\x46";␊
         |             ^^^^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
     `
+
+## invalid(1): a = `a\\b`
+
+> Input
+
+    `␊
+      1 | a = \`a\\\\b\`␊
+    `
+
+> Output
+
+    `␊
+      1 | a = String.raw\`a\\b\`␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | a = \`a\\\\b\`␊
+        |     ^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `
+
+## invalid(2): a = `a\\b${foo}cd`
+
+> Input
+
+    `␊
+      1 | a = \`a\\\\b${foo}cd\`␊
+    `
+
+> Output
+
+    `␊
+      1 | a = String.raw\`a\\b${foo}cd\`␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | a = \`a\\\\b${foo}cd\`␊
+        |     ^^^^^^^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `
+
+## invalid(3): a = `a\\b${foo}cd${foo.bar}e\\f`
+
+> Input
+
+    `␊
+      1 | a = \`a\\\\b${foo}cd${foo.bar}e\\\\f\`␊
+    `
+
+> Output
+
+    `␊
+      1 | a = String.raw\`a\\b${foo}cd${foo.bar}e\\f\`␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | a = \`a\\\\b${foo}cd${foo.bar}e\\\\f\`␊
+        |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `
+
+## invalid(4): a = `b${foo}${foo.bar}a\\b`
+
+> Input
+
+    `␊
+      1 | a = \`b${foo}${foo.bar}a\\\\b\`␊
+    `
+
+> Output
+
+    `␊
+      1 | a = String.raw\`b${foo}${foo.bar}a\\b\`␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | a = \`b${foo}${foo.bar}a\\\\b\`␊
+        |     ^^^^^^^^^^^^^^^^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `
+
+## invalid(5): a = `a\\b${"c\\d"}e`
+
+> Input
+
+    `␊
+      1 | a = \`a\\\\b${"c\\\\d"}e\`␊
+    `
+
+> Output
+
+    `␊
+      1 | a = String.raw\`a\\b${String.raw\`c\\d\`}e\`␊
+    `
+
+> Error 1/2
+
+    `␊
+    > 1 | a = \`a\\\\b${"c\\\\d"}e\`␊
+        |     ^^^^^^^^^^^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `
+
+> Error 2/2
+
+    `␊
+    > 1 | a = \`a\\\\b${"c\\\\d"}e\`␊
+        |            ^^^^^^ \`String.raw\` should be used to avoid escaping \`\\\`.␊
+    `