refactor tests

* factor out duplicated code
* make tests an importable package
* idiomatic pytest usage
* do not touch files outside of the tmp test tree and do not depend on
  external state (except for /nix/store ☹)
* run coverage to root out dead code

pyproject.toml

@@ -4,6 +4,11 @@ line-length = 88
 select = ["E", "F", "I"]
 ignore = [ "E501" ]
 
+[tool.coverage.report]
+exclude_lines = [
+  "pragma: no cover",
+  "pytest.skip",
+]
 [tool.mypy]
 python_version = "3.10"
 warn_redundant_casts = true

tests/case.py

@@ -0,0 +1,105 @@
+from __future__ import annotations
+
+import functools
+import logging
+import os
+import shutil
+import subprocess
+import textwrap
+from pathlib import Path
+
+import pytest
+
+CMD = Path | str
+
+log = logging.getLogger(__name__)
+
+TEST_ROOT = Path(__file__).parent
+
+PROJECT_ROOT = TEST_ROOT.parent
+
+NIX_DIRENV = PROJECT_ROOT / "direnvrc"
+
+
+class TestCase:
+    @pytest.fixture(autouse=True)
+    def _setup(self, tmp_path: Path) -> None:
+        self.root = tmp_path
+        log.debug(f"path: {self.root}")
+
+    @functools.cached_property
+    def home(self) -> Path:
+        return self.root / "home"
+
+    @functools.cached_property
+    def path(self) -> Path:
+        path = self.root / "cwd"
+        shutil.copytree(TEST_ROOT / "testenv", path)
+        return path
+
+    def _log_output(
+        self,
+        result: subprocess.CompletedProcess | subprocess.CalledProcessError,
+        errlevel: str = "debug",
+    ) -> None:
+        for out in ("stdout", "stderr"):
+            text = getattr(result, out).strip()
+            setattr(result, out, text)
+            if text:
+                getattr(log, errlevel if out == "stderr" else "debug")(
+                    f"{out[3:]}:{os.linesep if os.linesep in text else ' '}{text}"
+                )
+
+    def run(
+        self,
+        *cmd: CMD,
+        **env: str,
+    ) -> subprocess.CompletedProcess:
+        env = dict(PATH=os.environ["PATH"], HOME=str(self.home)) | env
+        command = list(map(str, cmd))
+        log.debug(f"$ {subprocess.list2cmdline(command)}")
+        try:
+            result = subprocess.run(
+                command,
+                capture_output=True,
+                check=True,
+                text=True,
+                cwd=self.path,
+                env=env,
+            )
+        except subprocess.CalledProcessError as exc:  # pragma: no cover
+            self._log_output(exc, errlevel="error")
+            raise
+        self._log_output(result)
+        return result
+
+    def nix_run(self, *cmd: CMD, **env: str) -> subprocess.CompletedProcess:
+        return self.run("nix", *cmd, **env)
+
+    def direnv_run(self, *cmd: CMD, **env: str) -> subprocess.CompletedProcess:
+        return self.run("direnv", *cmd, **env)
+
+    def direnv_exec(self, *cmd: CMD, **env: str) -> subprocess.CompletedProcess:
+        return self.run("direnv", "exec", ".", *cmd, **env)
+
+    def direnv_var(self, name: str, **env: str) -> subprocess.CompletedProcess:
+        return self.direnv_exec("sh", "-c", f"echo -n ${name}", **env)
+
+    def setup_envrc(
+        self, content: str, strict_env: bool, **env: str
+    ) -> subprocess.CompletedProcess:
+        text = textwrap.dedent(
+            f"""
+        {'strict_env' if strict_env else ''}
+        source {NIX_DIRENV}
+        {content}
+        """,
+        )
+        (self.path / ".envrc").write_text(text.strip())
+        return self.direnv_run("allow", **env)
+
+    def assert_direnv_var(self, name: str, **env: str) -> subprocess.CompletedProcess:
+        result = self.direnv_var(name, **env)
+        assert result.stdout == "OK"
+        assert "renewed cache" in result.stderr
+        return result

tests/conftest.py

@@ -1,4 +0,0 @@
-pytest_plugins = [
-    "direnv_project",
-    "root",
-]

tests/direnv_project.py

@@ -1,49 +0,0 @@
-import shutil
-import textwrap
-from dataclasses import dataclass
-from pathlib import Path
-from tempfile import TemporaryDirectory
-from typing import Iterator
-
-import pytest
-from procs import run
-
-
-@dataclass
-class DirenvProject:
-    dir: Path
-    nix_direnv: Path
-
-    @property
-    def envrc(self) -> Path:
-        return self.dir / ".envrc"
-
-    def setup_envrc(self, content: str, strict_env: bool) -> None:
-        text = textwrap.dedent(
-            f"""
-        {'strict_env' if strict_env else ''}
-        source {self.nix_direnv}
-        {content}
-        """
-        )
-        self.envrc.write_text(text)
-        run(["direnv", "allow"], cwd=self.dir)
-
-
-@pytest.fixture
-def direnv_project(test_root: Path, project_root: Path) -> Iterator[DirenvProject]:
-    """
-    Setups a direnv test project
-    """
-    with TemporaryDirectory() as _dir:
-        dir = Path(_dir) / "proj"
-        shutil.copytree(test_root / "testenv", dir)
-        shutil.copyfile(project_root / "flake.nix", dir / "flake.nix")
-        shutil.copyfile(project_root / "flake.lock", dir / "flake.lock")
-        nix_direnv = project_root / "direnvrc"
-
-        c = DirenvProject(Path(dir), nix_direnv)
-        try:
-            yield c
-        finally:
-            pass

tests/procs.py

@@ -1,23 +0,0 @@
-import subprocess
-from pathlib import Path
-from typing import IO, Any, List, Optional, Union
-
-_FILE = Union[None, int, IO[Any]]
-_DIR = Union[None, Path, str]
-
-
-def run(
-    cmd: List[str],
-    text: bool = True,
-    check: bool = True,
-    cwd: _DIR = None,
-    stderr: _FILE = None,
-    stdout: _FILE = None,
-    env: Optional[dict[str, str]] = None,
-) -> subprocess.CompletedProcess:
-    if cwd is not None:
-        print(f"cd {cwd}")
-    print("$ " + " ".join(cmd))
-    return subprocess.run(
-        cmd, text=text, check=check, cwd=cwd, stderr=stderr, stdout=stdout, env=env
-    )

tests/root.py

@@ -1,22 +0,0 @@
-from pathlib import Path
-
-import pytest
-
-TEST_ROOT = Path(__file__).parent.resolve()
-PROJECT_ROOT = TEST_ROOT.parent
-
-
-@pytest.fixture
-def test_root() -> Path:
-    """
-    Root directory of the tests
-    """
-    return TEST_ROOT
-
-
-@pytest.fixture
-def project_root() -> Path:
-    """
-    Root directory of the tests
-    """
-    return PROJECT_ROOT

tests/test_gc.py

@@ -1,92 +1,65 @@
-import subprocess
+from __future__ import annotations
-import sys
+
-import unittest
+import json
 
 import pytest
-from direnv_project import DirenvProject
+
-from procs import run
+from .case import TestCase
 
 
-def common_test(direnv_project: DirenvProject) -> None:
+class TestGc(TestCase):
-    run(["nix-collect-garbage"])
+    def common_test(self) -> None:
+        result = self.direnv_exec("hello")
+        assert "renewed cache" in result.stderr
+        assert "Executing shellHook." in result.stderr
 
-    testenv = str(direnv_project.dir)
+        self.nix_run("store", "gc")
 
-    out1 = run(
+        result = self.direnv_exec("hello")
-        ["direnv", "exec", testenv, "hello"],
+        assert "using cached dev shell" in result.stderr
-        stderr=subprocess.PIPE,
+        assert "Executing shellHook." in result.stderr
-        check=False,
-        cwd=direnv_project.dir,
-    )
-    sys.stderr.write(out1.stderr)
-    assert out1.returncode == 0
-    assert "renewed cache" in out1.stderr
-    assert "Executing shellHook." in out1.stderr
 
-    run(["nix-collect-garbage"])
+    def common_test_clean(self) -> None:
+        self.direnv_exec("hello")
+        files = [path for path in (self.path / ".direnv").iterdir() if path.is_file()]
+        rcs = [f for f in files if f.match("*.rc")]
+        profiles = [f for f in files if not f.match("*.rc")]
+        assert len(rcs) == 1, files
+        assert len(profiles) == 1, files
 
-    out2 = run(
+    @pytest.mark.parametrize("strict_env", [False, True])
-        ["direnv", "exec", testenv, "hello"],
+    def test_use_nix(self, strict_env: bool) -> None:
-        stderr=subprocess.PIPE,
+        self.setup_envrc("use nix", strict_env=strict_env)
-        check=False,
+        self.common_test()
-        cwd=direnv_project.dir,
-    )
-    sys.stderr.write(out2.stderr)
-    assert out2.returncode == 0
-    assert "using cached dev shell" in out2.stderr
-    assert "Executing shellHook." in out2.stderr
 
+        self.setup_envrc(
+            "use nix --argstr shellHook 'echo Executing hijacked shellHook.'",
+            strict_env=strict_env,
+        )
+        self.common_test_clean()
 
-def common_test_clean(direnv_project: DirenvProject) -> None:
+    def _parse_inputs(self, inputs: dict) -> list:
-    testenv = str(direnv_project.dir)
+        paths = [inputs["path"]]
+        for xinput in inputs["inputs"].values():
+            paths.extend(self._parse_inputs(xinput))
+        return paths
 
-    out3 = run(
+    @pytest.mark.parametrize("strict_env", [False, True])
-        ["direnv", "exec", testenv, "hello"],
+    def test_use_flake(self, strict_env: bool) -> None:
-        stderr=subprocess.PIPE,
+        self.setup_envrc("use flake", strict_env=strict_env)
-        check=False,
+        self.common_test()
-        cwd=direnv_project.dir,
+        inputs = list((self.path / ".direnv/flake-inputs").iterdir())
-    )
+        flake_inputs = self._parse_inputs(
-    sys.stderr.write(out3.stderr)
+            json.loads(
+                self.nix_run(
+                    "flake", "archive", "--json", "--no-write-lock-file"
+                ).stdout
+            )
+        )
+        # should only contain our flake-utils flake
+        assert len(inputs) == len(flake_inputs)
+        for symlink in inputs:
+            assert symlink.is_dir()
 
-    files = [
+        self.setup_envrc("use flake --impure", strict_env=strict_env)
-        path for path in (direnv_project.dir / ".direnv").iterdir() if path.is_file()
+        self.common_test_clean()
-    ]
-    rcs = [f for f in files if f.match("*.rc")]
-    profiles = [f for f in files if not f.match("*.rc")]
-    if len(rcs) != 1 or len(profiles) != 1:
-        print(files)
-    assert len(rcs) == 1
-    assert len(profiles) == 1
-
-
-@pytest.mark.parametrize("strict_env", [False, True])
-def test_use_nix(direnv_project: DirenvProject, strict_env: bool) -> None:
-    direnv_project.setup_envrc("use nix", strict_env=strict_env)
-    common_test(direnv_project)
-
-    direnv_project.setup_envrc(
-        "use nix --argstr shellHook 'echo Executing hijacked shellHook.'",
-        strict_env=strict_env,
-    )
-    common_test_clean(direnv_project)
-
-
-@pytest.mark.parametrize("strict_env", [False, True])
-def test_use_flake(direnv_project: DirenvProject, strict_env: bool) -> None:
-    direnv_project.setup_envrc("use flake", strict_env=strict_env)
-    common_test(direnv_project)
-    inputs = list((direnv_project.dir / ".direnv/flake-inputs").iterdir())
-    # should only contain our flake-utils flake
-    if len(inputs) != 4:
-        run(["nix", "flake", "archive", "--json"], cwd=direnv_project.dir)
-        print(inputs)
-    assert len(inputs) == 4
-    for symlink in inputs:
-        assert symlink.is_dir()
-
-    direnv_project.setup_envrc("use flake --impure", strict_env=strict_env)
-    common_test_clean(direnv_project)
-
-
-if __name__ == "__main__":
-    unittest.main()

tests/test_use_nix.py

@@ -1,67 +1,35 @@
+from __future__ import annotations
+
 import os
-import subprocess
-import sys
-import unittest
-from typing import Optional
 
 import pytest
-from direnv_project import DirenvProject
+
-from procs import run
+from .case import TestCase
 
 
-def direnv_exec(
+class TestUseNix(TestCase):
-    direnv_project: DirenvProject, cmd: str, env: Optional[dict[str, str]] = None
+    @pytest.mark.parametrize("strict_env", [False, True])
-) -> None:
+    def test_attrs(self, strict_env: bool) -> None:
-    args = ["direnv", "exec", str(direnv_project.dir), "sh", "-c", cmd]
+        self.setup_envrc("use nix -A subshell", strict_env=strict_env)
-    print("$ " + " ".join(args))
+        self.assert_direnv_var("THIS_IS_A_SUBSHELL")
-    out = run(
-        args,
-        stderr=subprocess.PIPE,
-        stdout=subprocess.PIPE,
-        check=False,
-        cwd=direnv_project.dir,
-        env=env,
-    )
-    sys.stdout.write(out.stdout)
-    sys.stderr.write(out.stderr)
-    assert out.returncode == 0
-    assert "OK\n" == out.stdout
-    assert "renewed cache" in out.stderr
 
+    @pytest.mark.parametrize("strict_env", [False, True])
+    def test_with_nix_path(self, strict_env: bool) -> None:
+        if (nix_path := os.environ.get("NIX_PATH")) is None:
+            pytest.skip("no parent NIX_PATH")
+        else:
+            self.setup_envrc(
+                "use nix --argstr someArg OK", strict_env=strict_env, NIX_PATH=nix_path
+            )
+            self.assert_direnv_var("SHOULD_BE_SET", NIX_PATH=nix_path)
 
-@pytest.mark.parametrize("strict_env", [False, True])
+    @pytest.mark.parametrize("strict_env", [False, True])
-def test_attrs(direnv_project: DirenvProject, strict_env: bool) -> None:
+    def test_args(self, strict_env: bool) -> None:
-    direnv_project.setup_envrc("use nix -A subshell", strict_env=strict_env)
+        self.setup_envrc("use nix --argstr someArg OK", strict_env=strict_env)
-    direnv_exec(direnv_project, "echo $THIS_IS_A_SUBSHELL")
+        self.assert_direnv_var("SHOULD_BE_SET")
 
-
+    @pytest.mark.parametrize("strict_env", [False, True])
-@pytest.mark.parametrize("strict_env", [False, True])
+    def test_no_files(self, strict_env: bool) -> None:
-def test_no_nix_path(direnv_project: DirenvProject, strict_env: bool) -> None:
+        self.setup_envrc("use nix -p hello", strict_env=strict_env)
-    direnv_project.setup_envrc("use nix --argstr someArg OK", strict_env=strict_env)
+        result = self.direnv_run("status")
-    env = os.environ.copy()
+        assert 'Loaded watch: "."' not in result.stdout
-    del env["NIX_PATH"]
-    direnv_exec(direnv_project, "echo $SHOULD_BE_SET", env=env)
-
-
-@pytest.mark.parametrize("strict_env", [False, True])
-def test_args(direnv_project: DirenvProject, strict_env: bool) -> None:
-    direnv_project.setup_envrc("use nix --argstr someArg OK", strict_env=strict_env)
-    direnv_exec(direnv_project, "echo $SHOULD_BE_SET")
-
-
-@pytest.mark.parametrize("strict_env", [False, True])
-def test_no_files(direnv_project: DirenvProject, strict_env: bool) -> None:
-    direnv_project.setup_envrc("use nix -p hello", strict_env=strict_env)
-    out = run(
-        ["direnv", "status"],
-        stderr=subprocess.PIPE,
-        stdout=subprocess.PIPE,
-        check=False,
-        cwd=direnv_project.dir,
-    )
-    assert out.returncode == 0
-    assert 'Loaded watch: "."' not in out.stdout
-
-
-if __name__ == "__main__":
-    unittest.main()

tests/testenv/.envrc

@@ -1,2 +0,0 @@
-source ../../direnvrc
-use nix

tests/testenv/flake.lock

@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1700856099,
+        "narHash": "sha256-RnEA7iJ36Ay9jI0WwP+/y4zjEhmeN6Cjs9VOFBH7eVQ=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "0bd59c54ef06bc34eca01e37d689f5e46b3fe2f1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

tests/testenv/flake.nix

@@ -1,6 +1,6 @@
 {
   description = "A very basic flake";
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
   inputs.flake-utils.url = "github:numtide/flake-utils";
 
   outputs = { self, nixpkgs, flake-utils }: