Add python paths option in config

Author: fangpenlin

mr/data_types.py

@@ -75,6 +75,13 @@ class ArtifactsConfig(BaseModel):
 class RepoConfig(BaseModel):
     """Repo-level config loaded from .makerrepo/config.yaml (or REPO_CONFIG_PATH)."""
 
+    pythonpaths: list[str] = Field(
+        default_factory=list,
+        description=(
+            "A list of paths to prepend to sys.path before importing user code. "
+            "Useful for src/ layouts (e.g. add 'src')."
+        ),
+    )
     artifacts: ArtifactsConfig | None = Field(
         default=None, description="Artifacts section"
     )

mr/utils.py

@@ -1,7 +1,9 @@
+import contextlib
 import dataclasses
 import importlib
 import os
 import pathlib
+import sys
 from importlib.machinery import SourceFileLoader
 from types import ModuleType
 
@@ -13,6 +15,46 @@
 from .data_types import RepoConfig
 
 
+@contextlib.contextmanager
+def apply_pythonpaths(
+    config: RepoConfig, repo_root: str | pathlib.Path | None = None
+) -> list[str]:
+    """
+    Temporarily prepend configured python paths to sys.path.
+
+    Paths are interpreted relative to ``repo_root`` when provided; otherwise relative
+    to the current working directory.
+    """
+    if not config.pythonpaths:
+        yield []
+        return
+
+    root = pathlib.Path(repo_root) if repo_root is not None else pathlib.Path.cwd()
+    added: list[str] = []
+
+    # Insert in reverse so the first entry ends up first in sys.path.
+    for raw in reversed(config.pythonpaths):
+        if not raw or not raw.strip():
+            continue
+        p = pathlib.Path(raw)
+        if not p.is_absolute():
+            p = root / p
+        value = str(p.resolve())
+        if value in sys.path:
+            continue
+        sys.path.insert(0, value)
+        added.append(value)
+
+    added.reverse()
+    try:
+        yield added
+    finally:
+        # Remove only what we added (one occurrence each).
+        for value in added:
+            if value in sys.path:
+                sys.path.remove(value)
+
+
 def load_module(module_spec: str) -> ModuleType:
     if module_spec.lower().endswith(".py") and os.path.exists(module_spec):
         module_path = pathlib.Path(module_spec)

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "makerrepo"
-version = "0.5.5"
+version = "0.5.6"
 description = "Open source library that brings Manufacturing As Code concept into build123d ecosystem"
 authors = [{ name = "Fang-Pen Lin", email = "fangpen@launchplatform.com" }]
 readme = "README.md"

tests/test_utils.py

@@ -7,6 +7,7 @@
 from mr.data_types import ArtifactsConfig
 from mr.data_types import DefaultArtifactConfig
 from mr.data_types import RepoConfig
+from mr.utils import apply_pythonpaths
 from mr.utils import apply_repo_config
 from mr.utils import find_python_modules
 from mr.utils import find_python_packages
@@ -34,13 +35,16 @@ def test_load_repo_config_custom_path_valid_yaml(tmp_path: pathlib.Path):
     config_file = tmp_path / "config.yaml"
     config_file.write_text(
         """
+pythonpaths:
+  - src
 artifacts:
   default_config:
     export_step: false
     export_3mf: true
 """
     )
     config = load_repo_config(config_file)
+    assert config.pythonpaths == ["src"]
     assert config.artifacts is not None
     assert config.artifacts.default_config.export_step is False
     assert config.artifacts.default_config.export_3mf is True
@@ -51,9 +55,68 @@ def test_load_repo_config_empty_yaml_returns_default(tmp_path: pathlib.Path):
     config_file = tmp_path / "empty.yaml"
     config_file.write_text("")
     config = load_repo_config(config_file)
+    assert config.pythonpaths == []
     assert config.artifacts is None
 
 
+def test_apply_pythonpaths_prepends_to_sys_path(
+    tmp_path: pathlib.Path, monkeypatch: pytest.MonkeyPatch
+):
+    (tmp_path / "src").mkdir()
+    config = RepoConfig(pythonpaths=["src"])
+    monkeypatch.chdir(tmp_path)
+    before = list(__import__("sys").path)
+    with apply_pythonpaths(config) as added:
+        assert added and added[0].endswith("/src")
+        assert __import__("sys").path[0] == added[0]
+        # Ensure we didn't blow away sys.path
+        assert len(__import__("sys").path) >= len(before)
+    assert __import__("sys").path == before
+
+
+def test_apply_pythonpaths_resolves_relative_to_repo_root(
+    tmp_path: pathlib.Path, monkeypatch: pytest.MonkeyPatch
+):
+    repo_root = tmp_path / "repo"
+    (repo_root / "src").mkdir(parents=True)
+    config = RepoConfig(pythonpaths=["src"])
+    monkeypatch.chdir(tmp_path)  # different cwd on purpose
+    before = list(__import__("sys").path)
+    with apply_pythonpaths(config, repo_root=repo_root) as added:
+        assert added == [str((repo_root / "src").resolve())]
+        assert __import__("sys").path[0] == added[0]
+    assert __import__("sys").path == before
+
+
+def test_apply_pythonpaths_does_not_remove_external_duplicate(
+    tmp_path: pathlib.Path, monkeypatch: pytest.MonkeyPatch
+):
+    """
+    If user code adds the same path again during the context, the context manager
+    should only remove its own inserted occurrence and leave the external one.
+    """
+    sys = __import__("sys")
+    (tmp_path / "src").mkdir()
+    config = RepoConfig(pythonpaths=["src"])
+    monkeypatch.chdir(tmp_path)
+
+    before = list(sys.path)
+    try:
+        with apply_pythonpaths(config) as added:
+            assert len(added) == 1
+            value = added[0]
+            assert sys.path[0] == value
+            # Simulate other code adding the same path during the context.
+            sys.path.append(value)
+            assert sys.path.count(value) == 2
+        # Our inserted occurrence is removed, but the "external" one remains.
+        assert value in sys.path
+        assert sys.path.count(value) == 1
+    finally:
+        # Restore sys.path so this test doesn't affect others.
+        sys.path[:] = before
+
+
 def test_apply_repo_config_fills_none_from_config():
     """apply_repo_config fills export_step/export_3mf when artifact has None."""