Refactor snapshot generator entry point (react#56090)

Summary:
Pull Request resolved: react#56090

Changelog: [Internal]

Refactors the `__main__.py` file of the snapshot generator:
- moves doxygen related logic to a separate file
- unifies snapshot generation branches
- reduces duplication

Reviewed By: cipolleschi

Differential Revision: D96455701

fbshipit-source-id: 7306fd2612bb401cd4ff02688ccaf38ecc71f239

Author: coado

scripts/cxx-api/parser/__main__.py

@@ -18,63 +18,34 @@
 import sys
 import tempfile
 
-from .config import parse_config_file
+from .config import ApiViewSnapshotConfig, parse_config_file
+from .doxygen import get_doxygen_bin, run_doxygen
 from .main import build_snapshot
 from .path_utils import get_react_native_dir
 from .snapshot_diff import check_snapshots
 
-DOXYGEN_CONFIG_FILE = ".doxygen.config.generated"
 
-
-def build_doxygen_config(
-    directory: str,
-    include_directories: list[str] = None,
-    exclude_patterns: list[str] = None,
-    definitions: dict[str, str | int] = None,
-    input_filter: str = None,
-) -> None:
-    if include_directories is None:
-        include_directories = []
-    if exclude_patterns is None:
-        exclude_patterns = []
-    if definitions is None:
-        definitions = {}
-
-    include_directories_str = " ".join(include_directories)
-    exclude_patterns_str = "\\\n".join(exclude_patterns)
-    if len(exclude_patterns) > 0:
-        exclude_patterns_str = f"\\\n{exclude_patterns_str}"
-
-    definitions_str = " ".join(
-        [
-            f'{key}="{value}"' if isinstance(value, str) else f"{key}={value}"
-            for key, value in definitions.items()
-        ]
-    )
-
-    input_filter_str = input_filter if input_filter else ""
-
-    # read the template file
-    with open(os.path.join(directory, ".doxygen.config.template")) as f:
-        template = f.read()
-
-    # replace the placeholders with the actual values
-    config = (
-        template.replace("${INPUTS}", include_directories_str)
-        .replace("${EXCLUDE_PATTERNS}", exclude_patterns_str)
-        .replace("${PREDEFINED}", definitions_str)
-        .replace("${DOXYGEN_INPUT_FILTER}", input_filter_str)
-    )
-
-    # write the config file
-    with open(os.path.join(directory, DOXYGEN_CONFIG_FILE), "w") as f:
-        f.write(config)
+def run_command(
+    cmd: list[str],
+    label: str,
+    verbose: bool = False,
+    **kwargs,
+) -> subprocess.CompletedProcess:
+    """Run a subprocess command with consistent error handling."""
+    result = subprocess.run(cmd, **kwargs)
+    if result.returncode != 0:
+        if verbose:
+            print(f"{label} finished with error: {result.stderr}")
+        sys.exit(1)
+    elif verbose:
+        print(f"{label} finished successfully")
+    return result
 
 
 def build_codegen(platform: str, verbose: bool = False) -> str:
     react_native_dir = os.path.join(get_react_native_dir(), "packages", "react-native")
 
-    result = subprocess.run(
+    run_command(
         [
             "node",
             "./scripts/generate-codegen-artifacts.js",
@@ -86,17 +57,11 @@ def build_codegen(platform: str, verbose: bool = False) -> str:
             platform,
             "--forceOutputPath",
         ],
+        label="Codegen",
+        verbose=verbose,
         cwd=react_native_dir,
     )
 
-    if result.returncode != 0:
-        if verbose:
-            print(f"Codegen finished with error: {result.stderr}")
-        sys.exit(1)
-    else:
-        if verbose:
-            print("Codegen finished successfully")
-
     return os.path.join(react_native_dir, "api", "codegen")
 
 
@@ -110,67 +75,35 @@ def build_snapshot_for_view(
     codegen_platform: str | None = None,
     verbose: bool = True,
     input_filter: str = None,
-) -> None:
-    # If there is already an output directory, delete it
-    if os.path.exists(os.path.join(react_native_dir, "api")):
-        if verbose:
-            print("Deleting existing output directory")
-        shutil.rmtree(os.path.join(react_native_dir, "api"))
-
+) -> str:
     if verbose:
         print(f"Generating API view: {api_view}")
 
+    api_dir = os.path.join(react_native_dir, "api")
+    if os.path.exists(api_dir):
+        if verbose:
+            print("  Deleting existing output directory")
+        shutil.rmtree(api_dir)
+
     if codegen_platform is not None:
         codegen_dir = build_codegen(codegen_platform, verbose=verbose)
         include_directories.append(codegen_dir)
     elif verbose:
-        print("Skipping codegen")
-
-    if verbose:
-        print("Generating Doxygen config file")
+        print("  Skipping codegen")
 
-    build_doxygen_config(
-        react_native_dir,
+    run_doxygen(
+        working_dir=react_native_dir,
         include_directories=include_directories,
         exclude_patterns=exclude_patterns,
         definitions=definitions,
         input_filter=input_filter,
+        verbose=verbose,
     )
 
     if verbose:
-        print("Running Doxygen")
-        if input_filter:
-            print(f"  Using input filter: {input_filter}")
+        print("  Building snapshot")
 
-    # Run doxygen with the config file
-    doxygen_bin = os.environ.get("DOXYGEN_BIN", "doxygen")
-
-    result = subprocess.run(
-        [doxygen_bin, DOXYGEN_CONFIG_FILE],
-        cwd=react_native_dir,
-        capture_output=True,
-        text=True,
-    )
-
-    # Check the result
-    if result.returncode != 0:
-        if verbose:
-            print(f"Doxygen finished with error: {result.stderr}")
-        sys.exit(1)
-    else:
-        if verbose:
-            print("Doxygen finished successfully")
-
-    # Delete the Doxygen config file
-    if verbose:
-        print("Deleting Doxygen config file")
-    os.remove(os.path.join(react_native_dir, DOXYGEN_CONFIG_FILE))
-
-    if verbose:
-        print("Building snapshot")
-
-    # build snapshot, convert to string, and save to file
-    snapshot = build_snapshot(os.path.join(react_native_dir, "api", "xml"))
+    snapshot = build_snapshot(os.path.join(api_dir, "xml"))
     snapshot_string = snapshot.to_string()
 
     output_file = os.path.join(output_dir, f"{api_view}Cxx.api")
@@ -183,6 +116,52 @@ def build_snapshot_for_view(
     return snapshot_string
 
 
+def build_snapshots(
+    snapshot_configs: list[ApiViewSnapshotConfig],
+    react_native_dir: str,
+    output_dir: str,
+    input_filter: str | None,
+    verbose: bool,
+    view_filter: str | None = None,
+    is_test: bool = False,
+) -> None:
+    if not is_test:
+        for config in snapshot_configs:
+            if view_filter and config.snapshot_name != view_filter:
+                continue
+
+            build_snapshot_for_view(
+                api_view=config.snapshot_name,
+                react_native_dir=react_native_dir,
+                include_directories=config.inputs,
+                exclude_patterns=config.exclude_patterns,
+                definitions=config.definitions,
+                output_dir=output_dir,
+                codegen_platform=config.codegen_platform,
+                verbose=verbose,
+                input_filter=input_filter,
+            )
+    else:
+        snapshot = build_snapshot_for_view(
+            api_view="Test",
+            react_native_dir=react_native_dir,
+            include_directories=[],
+            exclude_patterns=[],
+            definitions={},
+            output_dir=output_dir,
+            codegen_platform=None,
+            verbose=verbose,
+            input_filter=input_filter,
+        )
+
+        if verbose:
+            print(snapshot)
+
+
+def get_default_snapshot_dir() -> str:
+    return os.path.join(get_react_native_dir(), "scripts", "cxx-api", "api-snapshots")
+
+
 def main():
     parser = argparse.ArgumentParser(
         description="Generate API snapshots from C++ headers"
@@ -216,7 +195,7 @@ def main():
 
     verbose = not args.check
 
-    doxygen_bin = os.environ.get("DOXYGEN_BIN", "doxygen")
+    doxygen_bin = get_doxygen_bin()
     version_result = subprocess.run(
         [doxygen_bin, "--version"],
         capture_output=True,
@@ -225,7 +204,6 @@ def main():
     if verbose:
         print(f"Using Doxygen {version_result.stdout.strip()} ({doxygen_bin})")
 
-    # Define the path to the react-native directory
     react_native_package_dir = (
         os.path.join(get_react_native_dir(), "packages", "react-native")
         if not args.test
@@ -247,7 +225,6 @@ def main():
     if os.path.exists(input_filter_path):
         input_filter = f"python3 {input_filter_path}"
 
-    # Parse config file
     config_path = os.path.join(
         get_react_native_dir(), "scripts", "cxx-api", "config.yml"
     )
@@ -256,60 +233,28 @@ def main():
         get_react_native_dir(),
     )
 
-    def build_snapshots(output_dir: str, verbose: bool) -> None:
-        if not args.test:
-            for config in snapshot_configs:
-                if args.view and config.snapshot_name != args.view:
-                    continue
-
-                build_snapshot_for_view(
-                    api_view=config.snapshot_name,
-                    react_native_dir=react_native_package_dir,
-                    include_directories=config.inputs,
-                    exclude_patterns=config.exclude_patterns,
-                    definitions=config.definitions,
-                    output_dir=output_dir,
-                    codegen_platform=config.codegen_platform,
-                    verbose=verbose,
-                    input_filter=input_filter,
-                )
-        else:
-            snapshot = build_snapshot_for_view(
-                api_view="Test",
-                react_native_dir=react_native_package_dir,
-                include_directories=[],
-                exclude_patterns=[],
-                definitions={},
-                output_dir=output_dir,
-                codegen_platform=None,
-                verbose=verbose,
-                input_filter=input_filter,
-            )
-
-            if verbose:
-                print(snapshot)
+    with tempfile.TemporaryDirectory() as tmpdir:
+        snapshot_output_dir = (
+            tmpdir if args.check else args.output_dir or get_default_snapshot_dir()
+        )
 
-    if args.check:
-        with tempfile.TemporaryDirectory() as tmpdir:
-            build_snapshots(tmpdir, verbose=False)
+        build_snapshots(
+            output_dir=snapshot_output_dir,
+            verbose=not args.check,
+            snapshot_configs=snapshot_configs,
+            react_native_dir=react_native_package_dir,
+            input_filter=input_filter,
+            view_filter=args.view,
+            is_test=args.test,
+        )
 
-            snapshot_dir = args.snapshot_dir or os.path.join(
-                get_react_native_dir(), "scripts", "cxx-api", "api-snapshots"
-            )
+        if args.check:
+            snapshot_dir = args.snapshot_dir or get_default_snapshot_dir()
 
-            if not check_snapshots(tmpdir, snapshot_dir):
+            if not check_snapshots(snapshot_output_dir, snapshot_dir):
                 sys.exit(1)
 
             print("All snapshot checks passed")
-    else:
-        output_dir = (
-            args.output_dir
-            if args.output_dir
-            else os.path.join(
-                get_react_native_dir(), "scripts", "cxx-api", "api-snapshots"
-            )
-        )
-        build_snapshots(output_dir, verbose=True)
 
 
 if __name__ == "__main__":