Bug: file:// plugins with same filename incorrectly deduplicated #8759

Bug Description

Multiple file:// plugins with the same entry point filename (e.g., index.js) are incorrectly treated as duplicates during plugin loading, causing only the last one to load.

Steps to Reproduce

1. Create a config with multiple file:// plugins using standard entry points:

{
  "plugin": [
    "file:///path/to/plugin-a/dist/index.js",
    "file:///path/to/plugin-b/dist/index.js",
    "file:///path/to/plugin-c/dist/index.js"
  ]
}

2. Start OpenCode with debug logging:

OPENCODE_LOG_LEVEL=DEBUG opencode run "test" 2>&1 | grep "loading plugin"

3. Observe that only the last plugin loads

Expected Behavior

All three plugins should load since they have different paths.

Actual Behavior

Only plugin-c loads. The deduplication logic in getPluginName() extracts only the filename ("index") for all three plugins, marking them as duplicates.

Root Cause

In packages/opencode/src/config/config.ts, the getPluginName() function extracts only the filename for file:// URLs:

if (plugin.startsWith("file://")) {
  return path.parse(new URL(plugin).pathname).name  // Returns "index" for all
}

This was designed for npm package deduplication but doesn't account for file:// plugins where:

• Multiple plugins may use the same filename (standard practice: index.js)
• Plugins in different directories should not be considered duplicates
• Even plugins in the same directory with different filenames should be allowed

Impact

• Users cannot use multiple local plugins with standard entry point names
• No warning is shown when plugins are silently dropped
• Workaround requires renaming entry points to unique names (non-standard)

Environment

• OpenCode version: 1.1.23
• Node/Bun version: Bun 1.3.5
• OS: Linux

Related

This affects anyone using local plugin development with standard JavaScript conventions.