fix: preserve canonical snippet names (#1380)

* fix: preserve canonical snippet names

* test: cover same-directory snippet alias precedence

---------

Co-authored-by: Isaac Sanchez <isanchez-hawkins@arize.com>

packages/web/server/lib/opencode/snippets.js

@@ -85,27 +85,38 @@ function loadSnippetFile(dir, filename, source) {
   };
 }
 
-function registerSnippet(registry, snippet) {
+function removeSnippetAliases(registry, snippet, canonicalNames) {
+  for (const alias of snippet.aliases) {
+    const aliasKey = alias.toLowerCase();
+    if (canonicalNames.has(aliasKey)) continue;
+    if (registry.get(aliasKey) === snippet) registry.delete(aliasKey);
+  }
+}
+
+function registerSnippet(registry, snippet, canonicalNames) {
   const key = snippet.name.toLowerCase();
   const existing = registry.get(key);
-  if (existing) {
-    for (const alias of existing.aliases) registry.delete(alias.toLowerCase());
+  if (existing?.name.toLowerCase() === key) {
+    removeSnippetAliases(registry, existing, canonicalNames);
   }
   registry.set(key, snippet);
+  canonicalNames.add(key);
   for (const alias of snippet.aliases) {
-    if (SNIPPET_NAME_PATTERN.test(alias)) registry.set(alias.toLowerCase(), snippet);
+    const aliasKey = alias.toLowerCase();
+    if (SNIPPET_NAME_PATTERN.test(alias) && !canonicalNames.has(aliasKey)) registry.set(aliasKey, snippet);
   }
 }
 
 function loadSnippetRegistry(workingDirectory) {
   const registry = new Map();
+  const canonicalNames = new Set();
   for (const { dir, source } of getLoadDirs(workingDirectory)) {
     if (!fs.existsSync(dir)) continue;
     for (const filename of fs.readdirSync(dir)) {
       if (!filename.endsWith(SNIPPET_EXTENSION)) continue;
       try {
         const snippet = loadSnippetFile(dir, filename, source);
-        if (snippet) registerSnippet(registry, snippet);
+        if (snippet) registerSnippet(registry, snippet, canonicalNames);
       } catch (error) {
         console.warn(`[Snippets] Failed to load ${path.join(dir, filename)}:`, error);
       }

packages/web/server/lib/opencode/snippets.test.js

@@ -44,6 +44,35 @@ describe('snippets', () => {
     expect(getSnippet('same', projectDir)?.content).toBe('New');
   });
 
+  test('canonical snippet names take precedence over colliding aliases', () => {
+    writeSnippet('.opencode/snippets/review.md', 'Review by name');
+    writeSnippet('.opencode/snippet/helper.md', '---\naliases: [review, help]\n---\nReview by alias');
+
+    expect(getSnippet('review', projectDir)).toEqual(expect.objectContaining({ name: 'review', content: 'Review by name' }));
+    expect(getSnippet('help', projectDir)).toEqual(expect.objectContaining({ name: 'helper', content: 'Review by alias' }));
+    expect(expandSnippets('Use #review and #help', projectDir)).toBe('Use Review by name and Review by alias');
+  });
+
+  test('canonical snippet names override earlier same-directory aliases', () => {
+    writeSnippet('.opencode/snippet/alias-first.md', '---\naliases: [review, assist]\n---\nReview by alias');
+    writeSnippet('.opencode/snippet/review.md', 'Review by name');
+
+    const snippetDir = path.join(projectDir, '.opencode', 'snippet');
+    const originalReaddirSync = fs.readdirSync;
+    fs.readdirSync = function readdirSync(dir, ...args) {
+      if (dir === snippetDir) return ['alias-first.md', 'review.md'];
+      return originalReaddirSync.call(fs, dir, ...args);
+    };
+
+    try {
+      expect(getSnippet('review', projectDir)).toEqual(expect.objectContaining({ name: 'review', content: 'Review by name' }));
+      expect(getSnippet('assist', projectDir)).toEqual(expect.objectContaining({ name: 'alias-first', content: 'Review by alias' }));
+      expect(expandSnippets('Use #review and #assist', projectDir)).toBe('Use Review by name and Review by alias');
+    } finally {
+      fs.readdirSync = originalReaddirSync;
+    }
+  });
+
   test('creates updates and deletes snippets', () => {
     expect(createSnippet('custom-one', { content: 'Body', aliases: ['co'] }, projectDir, 'project')).toEqual(
       expect.objectContaining({ name: 'custom-one', content: 'Body', aliases: ['co'] }),