refactor!: improved run error handling and improved API

src/pytest_copier/errors.py

@@ -9,5 +9,5 @@ class CopierTaskError(CopierError):
     """Triggered by post-generation tasks"""
 
 
-class ProjectRunError(CopierError):
-    """Triggered by a command executed in th project"""
+class RunError(CopierError):
+    """Triggered by a failed command"""

src/pytest_copier/plugin.py

@@ -1,13 +1,13 @@
 from __future__ import annotations
 
-import shlex
 import subprocess
 
 from dataclasses import dataclass
+from functools import cached_property
 from io import StringIO
 from pathlib import Path
 from shutil import copy, copytree
-from typing import TYPE_CHECKING, Any, Mapping, cast
+from typing import TYPE_CHECKING, Any, cast
 
 import pytest
 import yaml
@@ -18,7 +18,7 @@
 from plumbum import local
 from pytest_dir_equal import DEFAULT_IGNORES, DiffRepr, assert_dir_equal
 
-from .errors import CopierTaskError, ProjectRunError
+from .errors import CopierTaskError, RunError
 
 if TYPE_CHECKING:
     from pytest_gitconfig import GitConfig
@@ -45,22 +45,24 @@ def expected_lines(self) -> list[str]:
         return self._as_lines(self.expected)
 
 
-def run(cmd: str, *args, **kwargs) -> None:
-    args = [cmd, *args] if args else shlex.split(cmd)  # type: ignore
+def run(cmd: str, *args, **kwargs) -> str:
+    args = [cmd, *args] if args else cmd  # type: ignore
     try:
-        subprocess.run(args, check=True, capture_output=True, **kwargs)
+        return subprocess.check_output(
+            args, text=True, stderr=subprocess.STDOUT, shell=True, **kwargs
+        )
     except subprocess.CalledProcessError as e:
         out = StringIO()
         tw = TerminalWriter(out)
-        output = e.stdout.decode("utf-8").replace("\n", "\n>>> ")
-        error = e.stderr.decode("utf-8").replace("\n", "\n>>> ")
         tw.hasmarkup = True
-        tw.line(f"{str(e)}\n")
-        if output:
-            tw.line(f"Standard output:\n>>> {output}\n")
-        if error:
-            tw.line(f"Standard error:\n>>> {error}")
-        raise RuntimeError(out.getvalue()) from e
+        tw.line(f"❌ {str(e)}\n")
+        if e.output:
+            prefix = tw.markup("│ ", red=True)
+            tw.line("╭╼ Combined output:")
+            for line in e.output.splitlines():
+                tw.line(f"{prefix} {line}")
+            tw.line("╰╼")
+        raise RunError(out.getvalue()) from e
 
 
 @pytest.fixture(scope="session")
@@ -119,16 +121,16 @@ def copier_template(
 @dataclass
 class CopierFixture:
     template: Path
-    dst: Path
     defaults: dict[str, Any]
+    monkeypatch: pytest.MonkeyPatch
 
-    def copy(self, **data) -> CopierProject:
+    def copy(self, dst: Path, **data) -> CopierProject:
         """Copy a template given some answers"""
         __tracebackhide__ = True
         try:
             run_copy(
                 str(self.template),
-                self.dst,
+                dst,
                 overwrite=True,
                 cleanup_on_error=False,
                 unsafe=True,
@@ -140,15 +142,14 @@ def copy(self, **data) -> CopierProject:
             # we can produce a more streamlined error report
             # we explicitly raise form None to cut the inner stacktrace too
             raise CopierTaskError(f"❌ {e}") from None
-        return CopierProject(self.dst)
+        return CopierProject(dst, self)
 
-    def update(self, **data) -> CopierProject:
+    def update(self, project: Path, **data) -> CopierProject:
         """Update a template given some answers"""
         __tracebackhide__ = True
         try:
             run_update(
-                str(self.template),
-                self.dst,
+                project,
                 overwrite=True,
                 cleanup_on_error=False,
                 unsafe=True,
@@ -159,9 +160,9 @@ def update(self, **data) -> CopierProject:
             # we catch those error which are triggered by tasks
             # we can produce a more streamlined error report
             raise CopierTaskError(f"❌ {e}") from None
-        return CopierProject(self.dst)
+        return CopierProject(project, self)
 
-    def context(self, **answers) -> Mapping[str, Any]:
+    def context(self, **answers) -> dict[str, Any]:
         """Get the context rendered given some answers"""
         __tracebackhide__ = True
         worker = self.worker(**answers)
@@ -171,38 +172,54 @@ def context(self, **answers) -> Mapping[str, Any]:
         ctx = env.context_class(env, data, "", {}, env.globals)
         return ctx.get_all()
 
-    def worker(self, **answers) -> Worker:
+    def worker(self, dst: Path = Path(), **answers) -> Worker:
         """Get a worker with prefilled answers"""
         return Worker(
             src_path=str(self.template),
-            dst_path=self.dst,
+            dst_path=dst,
             unsafe=True,
             defaults=True,
             data={**self.defaults, **answers},
         )
 
+    def delenv(self, var: str):
+        """Shortcut to monkeypatch.delenv both builtin os.environ and plumbum.local.env in Copier"""
+        self.monkeypatch.delenv(var, raising=False)
+        self.monkeypatch.delitem(local.env, var, raising=False)
+
+    def setenv(self, var: str, value: str):
+        """Shortcut to monkeypatch.setenv builtin os.environ and plumbum.local.env in Copier"""
+        self.monkeypatch.setenv(var, value)
+        self.monkeypatch.setitem(local.env, var, value)
+
 
 @dataclass
 class CopierProject:
     path: Path
+    copier: CopierFixture
 
-    def update(
-        self,
-    ):
-        pass
+    def update(self, **data) -> CopierProject:
+        return self.copier.update(self.path, **data)
+
+    @cached_property
+    def answers(self) -> dict[str, Any]:
+        return self.load_answers(self.path)
+
+    @cached_property
+    def context(self) -> dict[str, Any]:
+        return self.copier.context(**self.answers)
 
     def assert_answers(self, expected: Path):
         __tracebackhide__ = True
         expected_answers = self.load_answers(expected)
-        answers = self.load_answers(self.path)
-        if answers != expected_answers:
+        if self.answers != expected_answers:
             out = StringIO()
             tw = TerminalWriter(out)
             tw.hasmarkup = True
             tw.line("❌ Answers are different")
-            AnsersDiffRepr("Answers", answers, expected_answers).toterminal(tw)
+            AnsersDiffRepr("Answers", self.answers, expected_answers).toterminal(tw)
             raise AssertionError(out.getvalue())
-        assert answers == expected_answers
+        assert self.answers == expected_answers
 
     def load_answers(self, root: Path) -> dict[str, Any]:
         file = root / ANSWERS_FILE
@@ -217,15 +234,15 @@ def assert_equal(self, expected: Path, ignore: list[str] | None = None):
         ignore = DEFAULT_IGNORES + [ANSWERS_FILE] + (ignore or [])
         assert_dir_equal(self.path, expected, ignore=ignore)
 
-    def run(self, command: str, **kwargs):
+    def run(self, command: str, **kwargs) -> str:
         """Run a command in the rendered project"""
         __tracebackhide__ = True
         try:
-            run(*shlex.split(command), cwd=self.path, **kwargs)
-        except subprocess.CalledProcessError as e:
+            return run(command, cwd=self.path, **kwargs)
+        except RunError as e:
             # produce a more streamlined error report
             # we explicitly raise form None to cut the inner stacktrace too
-            raise ProjectRunError(f"❌ {e}") from None
+            raise RuntimeError(str(e)) from None
 
     def __truediv__(self, key):
         """Provide pathlib-like support"""
@@ -241,5 +258,9 @@ def copier_defaults() -> dict[str, Any]:
 
 
 @pytest.fixture
-def copier(tmp_path: Path, copier_template: Path, copier_defaults: dict[str, Any]) -> CopierFixture:
-    return CopierFixture(template=copier_template, dst=tmp_path / "dst", defaults=copier_defaults)
+def copier(
+    copier_template: Path, copier_defaults: dict[str, Any], monkeypatch: pytest.MonkeyPatch
+) -> CopierFixture:
+    return CopierFixture(
+        template=copier_template, defaults=copier_defaults, monkeypatch=monkeypatch
+    )