Improve source layout test discovery (#247)

- When `./tests` is present, try to test that instead of packagename
- If src layout is used, there's no need to switch away from the source directory when testing
- No longer use import-mode=importlib, which meant that packages could not do
  relative imports in tests

.pre-commit-config.yaml

@@ -41,6 +41,10 @@ repos:
     rev: 6f546f30c2b142ad5b3edcf20e3d27cf1789b932 # frozen: v1.10.1
     hooks:
       - id: mypy
+        exclude: |
+          (?x)(
+            ^example_pkg_src/
+          )
 
   - repo: https://github.com/codespell-project/codespell
     rev: "193cd7d27cd571f79358af09a8fb8997e54f8fff" # frozen: v2.3.0

example_pkg/example_pkg/_core.pyi

@@ -0,0 +1 @@
+def echo(str) -> None: ...

example_pkg_src/.gitattributes

@@ -0,0 +1,2 @@
+.* export-ignore
+.spin -export-ignore

example_pkg_src/.gitignore

@@ -0,0 +1,5 @@
+build
+build-install
+.mesonpy-native-file.ini
+dist/
+doc/_build

example_pkg_src/meson.build

@@ -0,0 +1,20 @@
+project(
+  'spin-example-pkg',
+  'c',
+  version: '0.0.dev0',
+  license: 'BSD-3',
+  meson_version: '>= 0.64',
+  default_options: [
+    'buildtype=debugoptimized',
+    'c_std=c99',
+    'cpp_std=c++14',
+  ],
+)
+
+cc = meson.get_compiler('c')
+
+py_mod = import('python')
+py = py_mod.find_installation(pure: false)
+py_dep = py.dependency()
+
+subdir('src')

example_pkg_src/pyproject.toml

@@ -0,0 +1,20 @@
+[project]
+name = "example_pkg"
+version = "0.0dev0"
+requires-python = ">=3.7"
+description = "spin Example Package"
+
+[build-system]
+build-backend = "mesonpy"
+requires = [
+  "meson-python>=0.13.0rc0",
+]
+
+[tool.spin]
+package = 'example_pkg'
+
+[tool.spin.commands]
+"Build" = [
+  "spin.cmds.meson.build",
+  "spin.cmds.meson.test"
+]

example_pkg_src/src/__init__.py

@@ -0,0 +1,4 @@
+from ._core import echo
+
+__all__ = ["echo"]
+__version__ = "0.0.0dev0"

example_pkg_src/src/_core.pyi

@@ -0,0 +1 @@
+def echo(str) -> None: ...

example_pkg_src/src/coremodule.c

@@ -0,0 +1,44 @@
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+
+static PyObject *
+core_echo(PyObject *self, PyObject *args)
+{
+    const char *str;
+    PyObject *ret;
+
+    if (!PyArg_ParseTuple(args, "s", &str))
+        return NULL;
+
+    printf("%s\n", str);
+
+    ret = PyLong_FromLong(42);
+    Py_INCREF(ret);
+    return ret;
+}
+
+static PyMethodDef CoreMethods[] = {
+    {"echo",  core_echo, METH_VARARGS, "Echo a string and return 42"},
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+static struct PyModuleDef coremodule = {
+    PyModuleDef_HEAD_INIT,
+    "core",   /* name of module */
+    NULL,     /* module documentation, may be NULL */
+    -1,       /* size of per-interpreter state of the module,
+                 or -1 if the module keeps state in global variables. */
+    CoreMethods
+};
+
+PyMODINIT_FUNC
+PyInit__core(void)
+{
+    PyObject *m;
+
+    m = PyModule_Create(&coremodule);
+    if (m == NULL)
+        return NULL;
+
+    return m;
+}

example_pkg_src/src/meson.build

@@ -0,0 +1,18 @@
+py.extension_module(
+  '_core',
+  'coremodule.c',
+  install: true,
+  subdir: 'example_pkg'
+)
+
+python_sources = [
+  '__init__.py',
+  'conftest.py'
+]
+
+py.install_sources(
+  python_sources,
+  subdir: 'example_pkg'
+)
+
+install_subdir('submodule', install_dir: py.get_install_dir() / 'example_pkg')

example_pkg_src/tests/submodule/test_submodule.py

@@ -0,0 +1,2 @@
+def test_something():
+    pass

example_pkg_src/tests/test_core.py

@@ -0,0 +1,6 @@
+from example_pkg import echo  # type: ignore[attr-defined]
+
+
+def test_core():
+    ans = echo("hello world")
+    assert ans == 42

spin/cmds/meson.py

@@ -499,12 +499,16 @@ def test(
         raise SystemExit(1)
 
     # User did not specify what to test, so we test
-    # the full package
+    # the full package, or the tests directory if that is present
     if not (pytest_args or tests):
-        pytest_args = ("--pyargs", package)
+        if os.path.isdir("./tests"):
+            # tests dir exists, presuming you are not shipping tests
+            # with your package, and prefer to run those instead
+            pytest_args = (os.path.abspath("./tests"),)
+        else:
+            pytest_args = ("--pyargs", package)
     elif tests:
         if (os.path.sep in tests) or ("/" in tests):
-            # Tests specified as file path
             pytest_args = pytest_args + (tests,)
         else:
             # Otherwise tests given as modules
@@ -549,9 +553,6 @@ def test(
     if (n_jobs != "1") and ("-n" not in pytest_args):
         pytest_args = ("-n", str(n_jobs)) + pytest_args
 
-    if not any("--import-mode" in arg for arg in pytest_args):
-        pytest_args = ("--import-mode=importlib",) + pytest_args
-
     if verbose:
         pytest_args = ("-v",) + pytest_args
 
@@ -577,8 +578,11 @@ def test(
     if not os.path.exists(install_dir):
         os.mkdir(install_dir)
 
+    # Unless we have a src layout, we need to switch away from the current directory into build install to avoid importing ./package instead of the built package.
+    test_path = site_path if not os.path.isdir("./src") else None
+
     cwd = os.getcwd()
-    pytest_p = _run(cmd + list(pytest_args), cwd=site_path)
+    pytest_p = _run(cmd + list(pytest_args), cwd=test_path)
     os.chdir(cwd)
 
     if gcov:

spin/tests/conftest.py

@@ -5,21 +5,30 @@
 from spin import util
 
 
-@pytest.fixture(autouse=True)
-def pre_post_test():
+def dir_switcher(path):
     # Pre-test code
     cwd = os.getcwd()
-    os.chdir("example_pkg")
+    os.chdir(path)
 
     try:
         yield
     finally:
         # Post test code
         os.chdir(cwd)
-        util.run(["git", "clean", "-xdf"], cwd="example_pkg")
+        util.run(["git", "clean", "-xdf"], cwd=path)
         os.chdir(cwd)
 
 
+@pytest.fixture()
+def example_pkg():
+    yield from dir_switcher("example_pkg")
+
+
+@pytest.fixture()
+def example_pkg_src_layout():
+    yield from dir_switcher("example_pkg_src")
+
+
 @pytest.fixture
 def editable_install():
     util.run(["pip", "install", "--quiet", "--no-build-isolation", "-e", "."])

spin/tests/test_build_cmds.py

@@ -5,7 +5,10 @@
 from pathlib import Path
 
 import pytest
-from testutil import (
+
+from spin.cmds.util import run
+
+from .testutil import (
     skip_on_windows,
     skip_py_lt_311,
     skip_unless_linux,
@@ -14,10 +17,8 @@
     stdout,
 )
 
-from spin.cmds.util import run
-
 
-def test_basic_build():
+def test_basic_build(example_pkg):
     """Does the package build?"""
     spin("build")
 
@@ -27,21 +28,21 @@ def test_basic_build():
     ).exists(), "`build-install` folder not created after `spin build`"
 
 
-def test_debug_builds():
+def test_debug_builds(example_pkg):
     """Does spin generate gcov debug output files?"""
     spin("build", "--gcov")
 
     debug_files = Path(".").rglob("*.gcno")
     assert len(list(debug_files)) != 0, "debug files not generated for gcov build"
 
 
-def test_prefix_builds():
+def test_prefix_builds(example_pkg):
     """does spin build --prefix create a build-install directory with the correct structure?"""
     spin("build", "--prefix=/foobar/")
     assert (Path("build-install") / Path("foobar")).exists()
 
 
-def test_coverage_builds():
+def test_coverage_builds(example_pkg):
     """Does gcov test generate coverage files?"""
     spin("test", "--gcov")
 
@@ -58,7 +59,7 @@ def test_coverage_builds():
         ("sonarqube", Path("sonarqube.xml")),
     ],
 )
-def test_coverage_reports(report_type, output_file):
+def test_coverage_reports(example_pkg, report_type, output_file):
     """Does gcov test generate coverage reports?"""
     spin("test", "--gcov", f"--gcov-format={report_type}")
 
@@ -68,15 +69,15 @@ def test_coverage_reports(report_type, output_file):
     ), f"coverage report not generated for gcov build ({report_type})"
 
 
-def test_expand_pythonpath():
+def test_expand_pythonpath(example_pkg):
     """Does an $ENV_VAR get expanded in `spin run`?"""
     output = spin("run", "echo $PYTHONPATH")
     assert any(
         p in stdout(output) for p in ("site-packages", "dist-packages")
     ), f"Expected value of $PYTHONPATH, got {stdout(output)} instead"
 
 
-def test_run_stdout():
+def test_run_stdout(example_pkg):
     """Ensure `spin run` only includes command output on stdout."""
     p = spin(
         "run",
@@ -92,7 +93,7 @@ def test_run_stdout():
 # Detecting whether a file is executable is not that easy on Windows,
 # as it seems to take into consideration whether that file is associated as an executable.
 @skip_on_windows
-def test_recommend_run_python():
+def test_recommend_run_python(example_pkg):
     """If `spin run file.py` is called, is `spin run python file.py` recommended?"""
     with tempfile.NamedTemporaryFile(suffix=".py") as f:
         p = spin("run", f.name, sys_exit=False)
@@ -101,20 +102,20 @@ def test_recommend_run_python():
         ), "Failed to recommend `python run python file.py`"
 
 
-def test_sdist():
+def test_sdist(example_pkg):
     spin("sdist")
 
 
-def test_example():
+def test_example(example_pkg):
     spin("example")
 
 
-def test_docs():
+def test_docs(example_pkg):
     run(["pip", "install", "--quiet", "sphinx"])
     spin("docs")
 
 
-def test_spin_install():
+def test_spin_install(example_pkg):
     cwd = os.getcwd()
     spin("install")
     with tempfile.TemporaryDirectory() as d:
@@ -135,7 +136,7 @@ def test_spin_install():
 
 
 @skip_unless_linux
-def test_gdb():
+def test_gdb(example_pkg):
     p = spin(
         "gdb",
         "-c",
@@ -149,7 +150,7 @@ def test_gdb():
 
 
 @skip_unless_macos
-def test_lldb():
+def test_lldb(example_pkg):
     p = spin(
         "lldb",
         "-c",
@@ -163,7 +164,7 @@ def test_lldb():
 
 
 @skip_py_lt_311  # python command does not run on older pythons
-def test_parallel_builds():
+def test_parallel_builds(example_pkg):
     spin("build")
     spin("build", "-C", "parallel/build")
     p = spin("python", "--", "-c", "import example_pkg; print(example_pkg.__file__)")

spin/tests/test_cli.py

@@ -1,14 +1,14 @@
-from testutil import spin, stdout
-
 import spin as libspin
 
+from .testutil import spin, stdout
+
 
-def test_get_version():
+def test_get_version(example_pkg):
     p = spin("--version")
     assert stdout(p) == f"spin {libspin.__version__}"
 
 
-def test_arg_override():
+def test_arg_override(example_pkg):
     p = spin("example")
     assert "--test is: default override" in stdout(p)
     assert "Default kwd is: 3" in stdout(p)

spin/tests/test_editable.py

@@ -1,11 +1,11 @@
-from testutil import spin, stdout
+from .testutil import spin, stdout
 
 
-def test_detect_editable(editable_install):
+def test_detect_editable(example_pkg, editable_install):
     assert "Editable install of same source detected" in stdout(
         spin("build")
     ), "Failed to detect and warn about editable install"
 
 
-def test_editable_tests(editable_install):
+def test_editable_tests(example_pkg, editable_install):
     spin("test")