Fix template-link-rel-noopener: fix fixer and regex matching

- Use word-boundary regex to prevent substring matches
- When rel already exists with partial values, append missing values
  instead of inserting a duplicate rel attribute
- Add test cases for reversed order, additional values, and partial rel

Author: johanrd

lib/rules/template-link-rel-noopener.js

@@ -31,16 +31,34 @@ module.exports = {
         }
 
         const relAttr = node.attributes?.find((a) => a.name === 'rel');
-        const hasProperRel =
-          relAttr?.value?.type === 'GlimmerTextNode' &&
-          /noopener/.test(relAttr.value.chars) &&
-          /noreferrer/.test(relAttr.value.chars);
+        const relValue =
+          relAttr?.value?.type === 'GlimmerTextNode' ? relAttr.value.chars : '';
+        const hasNoopener = /(?:^|\s)noopener(?:\s|$)/.test(relValue);
+        const hasNoreferrer = /(?:^|\s)noreferrer(?:\s|$)/.test(relValue);
+        const hasProperRel = hasNoopener && hasNoreferrer;
 
         if (!hasProperRel) {
           context.report({
             node: targetAttr,
             messageId: 'missingRel',
             fix(fixer) {
+              if (relAttr && relAttr.value?.type === 'GlimmerTextNode') {
+                // rel attribute exists with a text value — append missing values
+                const oldValue = relAttr.value.chars;
+                const parts = oldValue.trim().split(/\s+/).filter(Boolean);
+                if (!hasNoopener) {
+                  parts.push('noopener');
+                }
+                if (!hasNoreferrer) {
+                  parts.push('noreferrer');
+                }
+                const newValue = parts.join(' ');
+                return fixer.replaceTextRange(
+                  [relAttr.value.range[0], relAttr.value.range[1]],
+                  newValue
+                );
+              }
+              // No rel attribute — insert one before the closing >
               const sourceCode = context.sourceCode;
               const openTag = sourceCode.getText(node).match(/^<a[^>]*/)[0];
               const insertPos = node.range[0] + openTag.length;

tests/lib/rules/template-link-rel-noopener.js

@@ -6,12 +6,39 @@ const ruleTester = new RuleTester({
   parserOptions: { ecmaVersion: 2022, sourceType: 'module' },
 });
 ruleTester.run('template-link-rel-noopener', rule, {
-  valid: ['<template><a href="/" target="_blank" rel="noopener noreferrer">Link</a></template>'],
+  valid: [
+    '<template><a href="/" target="_blank" rel="noopener noreferrer">Link</a></template>',
+    // reversed order
+    '<template><a href="/" target="_blank" rel="noreferrer noopener">Link</a></template>',
+    // with additional values
+    '<template><a href="/" target="_blank" rel="nofollow noreferrer noopener">Link</a></template>',
+    // no target="_blank" means no rel required
+    '<template><a href="/">Link</a></template>',
+  ],
   invalid: [
+    // no rel attribute at all
     {
       code: '<template><a href="/" target="_blank">Link</a></template>',
       output: '<template><a href="/" target="_blank" rel="noopener noreferrer">Link</a></template>',
       errors: [{ messageId: 'missingRel' }],
     },
+    // rel="noopener" only — missing noreferrer
+    {
+      code: '<template><a href="/" target="_blank" rel="noopener">Link</a></template>',
+      output: '<template><a href="/" target="_blank" rel="noopener noreferrer">Link</a></template>',
+      errors: [{ messageId: 'missingRel' }],
+    },
+    // rel="noreferrer" only — missing noopener
+    {
+      code: '<template><a href="/" target="_blank" rel="noreferrer">Link</a></template>',
+      output: '<template><a href="/" target="_blank" rel="noreferrer noopener">Link</a></template>',
+      errors: [{ messageId: 'missingRel' }],
+    },
+    // rel="nofollow" — present but wrong values
+    {
+      code: '<template><a href="/" target="_blank" rel="nofollow">Link</a></template>',
+      output: '<template><a href="/" target="_blank" rel="nofollow noopener noreferrer">Link</a></template>',
+      errors: [{ messageId: 'missingRel' }],
+    },
   ],
 });