Fix Groovy FunctionNodeTypes misconfiguration #6

Problem

Groovy method extraction returns 0 results because FunctionNodeTypes is configured with the wrong tree-sitter node type name.

Root Cause

The Groovy language spec uses function_definition but the tree-sitter-groovy grammar uses a different node type for method declarations. This means the pipeline never matches any Groovy methods.

Fix

1. Run the AST dump test on a Groovy file to see actual node types: go test ./internal/pipeline/ -run TestASTDump -v
2. Update FunctionNodeTypes in internal/lang/groovy.go to match the actual tree-sitter node type
3. Verify with the benchmark repo (Spock: https://github.com/spockframework/spock)

Impact

Unlocks method extraction for all Groovy code. Currently scores 29% — fixing this should jump to 50%+.

References

• Benchmark report: BENCHMARK_REPORT.md (Groovy section)
• Language spec: internal/lang/groovy.go