chore(core, langchain): add version consistency check pre-commit hooks (#34782)

.pre-commit-config.yaml

@@ -117,3 +117,15 @@ repos:
         entry: make -C libs/partners/qdrant format lint
         files: ^libs/partners/qdrant/
         pass_filenames: false
+      - id: core-version
+        name: check core version consistency
+        language: system
+        entry: make -C libs/core check_version
+        files: ^libs/core/(pyproject\.toml|langchain_core/version\.py)$
+        pass_filenames: false
+      - id: langchain-v1-version
+        name: check langchain version consistency
+        language: system
+        entry: make -C libs/langchain_v1 check_version
+        files: ^libs/langchain_v1/(pyproject\.toml|langchain/__init__\.py)$
+        pass_filenames: false

libs/core/Makefile

@@ -1,4 +1,4 @@
-.PHONY: all format lint test tests test_watch integration_tests help extended_tests
+.PHONY: all format lint test tests test_watch integration_tests help extended_tests check_version
 
 # Default target executed when no arguments are given to make.
 all: help
@@ -31,6 +31,9 @@ test_profile:
 check_imports: $(shell find langchain_core -name '*.py')
 	uv run --group test python ./scripts/check_imports.py $^
 
+check_version:
+	uv run python ./scripts/check_version.py
+
 extended_tests:
 	uv run --group test pytest --only-extended --disable-socket --allow-unix-socket $(TEST_FILE)
 
@@ -69,6 +72,7 @@ help:
 	@echo '----'
 	@echo 'format                       - run code formatters'
 	@echo 'lint                         - run linters'
+	@echo 'check_version                - validate version consistency'
 	@echo 'test                         - run unit tests'
 	@echo 'tests                        - run unit tests'
 	@echo 'test TEST_FILE=<test_file>   - run all tests in file'

libs/core/scripts/check_version.py

@@ -0,0 +1,65 @@
+"""Check version consistency between pyproject.toml and version.py.
+
+This script validates that the version defined in pyproject.toml matches
+the VERSION variable in langchain_core/version.py. Intended for use as
+a pre-commit hook to prevent version mismatches.
+"""
+
+import re
+import sys
+from pathlib import Path
+
+
+def get_pyproject_version(pyproject_path: Path) -> str | None:
+    """Extract version from pyproject.toml."""
+    content = pyproject_path.read_text()
+    match = re.search(r'^version\s*=\s*"([^"]+)"', content, re.MULTILINE)
+    return match.group(1) if match else None
+
+
+def get_version_py_version(version_path: Path) -> str | None:
+    """Extract VERSION from version.py."""
+    content = version_path.read_text()
+    match = re.search(r'^VERSION\s*=\s*"([^"]+)"', content, re.MULTILINE)
+    return match.group(1) if match else None
+
+
+def main() -> int:
+    """Validate version consistency."""
+    script_dir = Path(__file__).parent
+    package_dir = script_dir.parent
+
+    pyproject_path = package_dir / "pyproject.toml"
+    version_path = package_dir / "langchain_core" / "version.py"
+
+    if not pyproject_path.exists():
+        print(f"Error: {pyproject_path} not found")  # noqa: T201
+        return 1
+
+    if not version_path.exists():
+        print(f"Error: {version_path} not found")  # noqa: T201
+        return 1
+
+    pyproject_version = get_pyproject_version(pyproject_path)
+    version_py_version = get_version_py_version(version_path)
+
+    if pyproject_version is None:
+        print("Error: Could not find version in pyproject.toml")  # noqa: T201
+        return 1
+
+    if version_py_version is None:
+        print("Error: Could not find VERSION in langchain_core/version.py")  # noqa: T201
+        return 1
+
+    if pyproject_version != version_py_version:
+        print("Error: Version mismatch detected!")  # noqa: T201
+        print(f"  pyproject.toml: {pyproject_version}")  # noqa: T201
+        print(f"  langchain_core/version.py: {version_py_version}")  # noqa: T201
+        return 1
+
+    print(f"Version check passed: {pyproject_version}")  # noqa: T201
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

libs/langchain_v1/Makefile

@@ -1,4 +1,4 @@
-.PHONY: all start_services stop_services coverage coverage_agents test test_fast extended_tests test_watch test_watch_extended integration_tests check_imports lint format lint_diff format_diff lint_package lint_tests help
+.PHONY: all start_services stop_services coverage coverage_agents test test_fast extended_tests test_watch test_watch_extended integration_tests check_imports check_version lint format lint_diff format_diff lint_package lint_tests help
 
 # Default target executed when no arguments are given to make.
 all: help
@@ -69,6 +69,9 @@ integration_tests:
 check_imports: $(shell find langchain -name '*.py')
 	uv run python ./scripts/check_imports.py $^
 
+check_version:
+	uv run python ./scripts/check_version.py
+
 ######################
 # LINTING AND FORMATTING
 ######################
@@ -100,6 +103,7 @@ help:
 	@echo '-- LINTING --'
 	@echo 'format                       - run code formatters'
 	@echo 'lint                         - run linters'
+	@echo 'check_version                - validate version consistency'
 	@echo '-- TESTS --'
 	@echo 'coverage                     - run unit tests and generate coverage report'
 	@echo 'coverage_agents              - run middleware and agent tests with coverage report'

libs/langchain_v1/scripts/check_version.py

@@ -0,0 +1,65 @@
+"""Check version consistency between pyproject.toml and __init__.py.
+
+This script validates that the version defined in pyproject.toml matches
+the __version__ variable in langchain/__init__.py. Intended for use as
+a pre-commit hook to prevent version mismatches.
+"""
+
+import re
+import sys
+from pathlib import Path
+
+
+def get_pyproject_version(pyproject_path: Path) -> str | None:
+    """Extract version from pyproject.toml."""
+    content = pyproject_path.read_text()
+    match = re.search(r'^version\s*=\s*"([^"]+)"', content, re.MULTILINE)
+    return match.group(1) if match else None
+
+
+def get_init_version(init_path: Path) -> str | None:
+    """Extract __version__ from __init__.py."""
+    content = init_path.read_text()
+    match = re.search(r'^__version__\s*=\s*"([^"]+)"', content, re.MULTILINE)
+    return match.group(1) if match else None
+
+
+def main() -> int:
+    """Validate version consistency."""
+    script_dir = Path(__file__).parent
+    package_dir = script_dir.parent
+
+    pyproject_path = package_dir / "pyproject.toml"
+    init_path = package_dir / "langchain" / "__init__.py"
+
+    if not pyproject_path.exists():
+        print(f"Error: {pyproject_path} not found")  # noqa: T201
+        return 1
+
+    if not init_path.exists():
+        print(f"Error: {init_path} not found")  # noqa: T201
+        return 1
+
+    pyproject_version = get_pyproject_version(pyproject_path)
+    init_version = get_init_version(init_path)
+
+    if pyproject_version is None:
+        print("Error: Could not find version in pyproject.toml")  # noqa: T201
+        return 1
+
+    if init_version is None:
+        print("Error: Could not find __version__ in langchain/__init__.py")  # noqa: T201
+        return 1
+
+    if pyproject_version != init_version:
+        print("Error: Version mismatch detected!")  # noqa: T201
+        print(f"  pyproject.toml: {pyproject_version}")  # noqa: T201
+        print(f"  langchain/__init__.py: {init_version}")  # noqa: T201
+        return 1
+
+    print(f"Version check passed: {pyproject_version}")  # noqa: T201
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())