feat: merge generator config yaml

Author: chingor13

monorepo-migration/migrate.sh

@@ -56,6 +56,7 @@ TRANSFORM_SCRIPT="$TRANSFORM_SCRIPT_DIR/transform_workflow.py"
 MODERNIZE_POM_SCRIPT="$TRANSFORM_SCRIPT_DIR/modernize_pom.py"
 UPDATE_ROOT_POM_SCRIPT="$TRANSFORM_SCRIPT_DIR/update_root_pom.py"
 FIX_COPYRIGHT_SCRIPT="$TRANSFORM_SCRIPT_DIR/fix_copyright_headers.py"
+UPDATE_GENERATION_CONFIG_SCRIPT="$TRANSFORM_SCRIPT_DIR/update_generation_config.py"
 
 echo "Starting migration using git read-tree with isolated clones..."
 
@@ -209,17 +210,7 @@ fi
 echo "Updating generation_config.yaml..."
 SOURCE_CONFIG="$SOURCE_REPO_NAME/generation_config.yaml"
 if [ -f "$SOURCE_CONFIG" ]; then
-    # Extract the library entry (starts with - api_shortname)
-    # This assumes the source config only has one library or we want the first one
-    ENTRY=$(awk '/^  - api_shortname:/{flag=1; print $0; next} /^  - / && flag{flag=0} flag' "$SOURCE_CONFIG")
-    
-    # Simple cleanup: remove repo and repo_short if they exist
-    # Adjust indentation to match monorepo (0 spaces for -)
-    CLEAN_ENTRY=$(echo "$ENTRY" | sed '/repo:/d' | sed '/repo_short:/d' | sed 's/^  //')
-    
-    # Append to target generation_config.yaml
-    echo "" >> generation_config.yaml
-    echo "$CLEAN_ENTRY" >> generation_config.yaml
+    python3 "$UPDATE_GENERATION_CONFIG_SCRIPT" "generation_config.yaml" "$SOURCE_CONFIG"
 
     echo "Committing generation_config.yaml update..."
     git add generation_config.yaml

monorepo-migration/update_generation_config.py

@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import sys
+import yaml
+import re
+
+def get_library_id(lib):
+    """
+    Returns a unique identifier for a library.
+    Prefer 'library_name', then 'api_shortname'.
+    """
+    if 'library_name' in lib:
+        return f"java-{lib['library_name']}"
+    if 'api_shortname' in lib:
+        return f"java-{lib['api_shortname']}"
+    return "unknown"
+
+def merge_libraries(target_libs, source_libs):
+    """
+    Merges source_libs into target_libs.
+    Libraries are matched by get_library_id.
+    GAPICs are merged and deduplicated by proto_path.
+    The final list is sorted by library_id.
+    """
+    # Map from library_id to library dict
+    target_map = {get_library_id(lib): lib for lib in target_libs}
+
+    for s_lib in source_libs:
+        lib_id = get_library_id(s_lib)
+        
+        # Clean up source library (remove repo fields)
+        s_lib_cleaned = {k: v for k, v in s_lib.items() if k not in ('repo', 'repo_short')}
+        
+        if lib_id in target_map:
+            t_lib = target_map[lib_id]
+            # Merge GAPICs
+            t_gapics_list = t_lib.get('GAPICs', [])
+            s_gapics_list = s_lib_cleaned.get('GAPICs', [])
+            
+            # Map by proto_path for deduplication
+            proto_map = {g['proto_path']: g for g in t_gapics_list}
+            for g in s_gapics_list:
+                proto_map[g['proto_path']] = g
+            
+            # Sort GAPICs by proto_path
+            sorted_protos = sorted(proto_map.keys())
+            t_lib['GAPICs'] = [proto_map[p] for p in sorted_protos]
+            
+            # Update other fields from source
+            for k, v in s_lib_cleaned.items():
+                if k != 'GAPICs':
+                    t_lib[k] = v
+        else:
+            target_map[lib_id] = s_lib_cleaned
+
+    # Return sorted list of libraries
+    sorted_ids = sorted(target_map.keys())
+    return [target_map[lib_id] for lib_id in sorted_ids]
+
+def update_config(target_path, source_path):
+    with open(target_path, 'r') as f:
+        target_content = f.read()
+    
+    with open(source_path, 'r') as f:
+        source_data = yaml.safe_load(f) or {}
+
+    # Load target data
+    target_data = yaml.safe_load(target_content) or {}
+    
+    target_libs = target_data.get('libraries', [])
+    source_libs = source_data.get('libraries', [])
+    
+    merged_libs = merge_libraries(target_libs, source_libs)
+    target_data['libraries'] = merged_libs
+
+    # Write back
+    with open(target_path, 'w') as f:
+        # Check if there was a license header in the original file
+        header_match = re.search(r'^(#.*?\n\n)', target_content, re.DOTALL)
+        if header_match:
+            f.write(header_match.group(1))
+        
+        # Use yaml.dump to write the data.
+        # sort_keys=False to preserve order of fields within libraries if possible (YAML 1.2+ usually does, but pyyaml depends)
+        yaml.dump(target_data, f, sort_keys=False, default_flow_style=False, indent=2)
+
+if __name__ == "__main__":
+    if len(sys.argv) != 3:
+        print("Usage: python3 update_generation_config.py <target_config> <source_config>")
+        sys.exit(1)
+    
+    target_path = sys.argv[1]
+    source_path = sys.argv[2]
+    update_config(target_path, source_path)