Duplicate Code: JSON MCP RenderMCPConfig scaffolding across engine modules

[github-actions]

Overview

The latest commit (f3c7b792f95f8b3e6178f8612109832ca13dc627) contains repeated JSON MCP configuration scaffolding across engine implementations in pkg/workflow. The duplicated block is large enough (>10 lines) and appears in multiple engine-specific files with only small callback/path differences.

Critical Information

• Severity: Medium
• Pattern type: Structural duplication (copy-paste with minor variations)
• Occurrences: 3 primary occurrences
• Impacted area: MCP configuration rendering for CLI engines

Duplication Details

Pattern: Engine RenderMCPConfig setup repetition

• pkg/workflow/claude_mcp.go:12
• pkg/workflow/gemini_mcp.go:12
• pkg/workflow/copilot_mcp.go:12

The methods repeat the same sequence:

1. Log render start
2. Construct JSON renderer factory
3. Build gateway config with buildMCPGatewayConfig(workflowData)
4. Build standard JSON renderers
5. Call RenderJSONMCPConfig(...)

Representative duplicated block

createRenderer := buildMCPRendererFactory(workflowData, "json", false, false)

return RenderJSONMCPConfig(yaml, tools, mcpTools, workflowData, JSONMCPConfigOptions{
    ConfigPath:    "/tmp/gh-aw/mcp-config/mcp-servers.json",
    GatewayConfig: buildMCPGatewayConfig(workflowData),
    Renderers: buildStandardJSONMCPRenderers(workflowData, createRenderer, false, func(yaml *strings.Builder, toolName string, toolConfig map[string]any, isLast bool) error {
        // engine-specific callback only
        return ...
    }),
})

Impact Analysis

• Maintainability: Changes to shared JSON MCP behavior must be repeated in multiple files, increasing drift risk.
• Bug risk: Engine-specific files can diverge subtly when only one file is updated during future feature work.
• Code bloat: Repeated setup logic reduces signal-to-noise in engine modules.

Refactoring Recommendations

1. Extract a shared helper for JSON MCP rendering options

• Suggested location: pkg/workflow/mcp_renderer_helpers.go or pkg/workflow/mcp_engine_shared.go
• Helper input: config path, copilot flags, callback, optional tool filter
• Helper output: unified RenderJSONMCPConfig(...) invocation

2. Keep only engine-specific concerns in engine files

• Claude/Gemini: callback function and logger message
• Copilot: pre-step (mkdir) and FilterTool

Implementation Checklist

• Introduce shared helper for JSON MCP config scaffolding
• Update claude_mcp.go, gemini_mcp.go, and copilot_mcp.go to use helper
• Validate generated MCP config output parity for all engines
• Add/adjust focused unit tests around helper behavior

Analysis Metadata

• Analyzed scope: pkg/**/*.go (non-test files in changed commit)
• Deep semantic review focus: MCP gateway/config rendering paths
• Detection method: Serena symbol/body comparison + targeted pattern search
• Workflow run: §23328418561
• Analysis date: 2026-03-20 UTC

References:

• §23328418561

Warning

⚠️ Firewall blocked 1 domain

The following domain was blocked by the firewall during workflow execution:

• ab.chatgpt.com

To allow these domains, add them to the network.allowed list in your workflow frontmatter:

network:
  allowed:
    - defaults
    - "ab.chatgpt.com"

See Network Configuration for more information.

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