allow_outside_tmpdir

Author: blueyed

src/_pytest/pytester.py

@@ -666,11 +666,26 @@ def maketxtfile(self, *args, **kwargs):
         """Shortcut for .makefile() with a .txt extension."""
         return self._makefile(".txt", args, kwargs)
 
-    def makefiles(self, **kwargs: str) -> List[Path]:
-        """Create the given set of files."""
+    def makefiles(
+        self, files: Dict[str, str], allow_outside_tmpdir=False
+    ) -> List[Path]:
+        """Create the given set of files.
+
+        Unlike other helpers like :func:`makepyfile` this allows to specify
+        absolute paths, which need to be below :attr:`tmpdir` by default
+        (use `allow_outside_tmpdir` to write arbitrary files).
+        """
         paths = []
-        for fname, content in kwargs.items():
-            path = Path(self.tmpdir).joinpath(Path(fname))
+        if allow_outside_tmpdir:
+            validated_files = {Path(k): v for k, v in files.items()}
+        else:
+            tmpdir_path = Path(self.tmpdir)
+            validated_files = {
+                Path(k).absolute().relative_to(tmpdir_path): v for k, v in files.items()
+            }
+
+        for fpath, content in validated_files.items():
+            path = Path(self.tmpdir).joinpath(fpath)
             with open(str(path), "w") as fp:
                 fp.write(textwrap.dedent(content))
             paths.append(path)

testing/test_pytester.py

@@ -1,7 +1,9 @@
+import builtins
 import os
 import subprocess
 import sys
 import time
+from contextlib import contextmanager
 from typing import List
 
 import py.path
@@ -15,6 +17,7 @@
 from _pytest.pytester import CwdSnapshot
 from _pytest.pytester import HookRecorder
 from _pytest.pytester import LineMatcher
+from _pytest.pytester import MonkeyPatch
 from _pytest.pytester import SysModulesSnapshot
 from _pytest.pytester import SysPathsSnapshot
 from _pytest.pytester import Testdir
@@ -713,16 +716,43 @@ def test_error2(bad_fixture):
     assert result.parseoutcomes() == {"error": 2}
 
 
-def test_testdir_makefiles(testdir: Testdir) -> None:
-    abspath = str(testdir.tmpdir / "bar")
-    created_paths = testdir.makefiles(**{"foo": "", abspath: ""})
+def test_testdir_makefiles(testdir: Testdir, monkeypatch: MonkeyPatch) -> None:
+    tmpdir = testdir.tmpdir
+
+    abspath = str(tmpdir / "bar")
+
+    created_paths = testdir.makefiles({"foo": "", abspath: ""})
     p1 = created_paths[0]
     assert isinstance(p1, Path)
-    relpath = testdir.tmpdir / "foo"
+    relpath = tmpdir / "foo"
     assert p1 == relpath
 
     p2 = created_paths[1]
     assert p2.exists()
     assert str(p2) == abspath
 
-    assert testdir.makefiles() == []
+    assert testdir.makefiles({}) == []
+
+    # Disallows creation outside of tmpdir by default.
+    with pytest.raises(
+        ValueError, match="'/abspath' does not start with '{}'".format(tmpdir)
+    ):
+        testdir.makefiles({"shouldnotbecreated": "", "/abspath": ""})
+    # Validation before creating anything.
+    assert not Path("shouldnotbecreated").exists()
+
+    # Support writing arbitrary files on request.
+    open_calls = []
+    orig_open = builtins.open
+
+    @contextmanager
+    def mocked_open(*args):
+        open_calls.append(["__enter__", args])
+        with orig_open(os.devnull, *args[1:]) as fp:
+            yield fp
+
+    with monkeypatch.context() as mp:
+        mp.setattr(builtins, "open", mocked_open)
+        created_paths = testdir.makefiles({"/abspath": ""}, allow_outside_tmpdir=True)
+    assert created_paths == [Path("/abspath")]
+    assert open_calls == [["__enter__", ("/abspath", "w")]]