fix: revert pyproject.toml changes on error

src/poetry_plugin_up/command.py

@@ -60,6 +60,7 @@ def handle(self) -> int:
 
         selector = VersionSelector(self.poetry.pool)
         pyproject_content = self.poetry.file.read()
+        original_pyproject_content = self.poetry.file.read()
 
         for group in self.get_groups():
             for dependency in group.dependencies:
@@ -78,14 +79,19 @@ def handle(self) -> int:
 
         # write new content to pyproject.toml
         self.poetry.file.write(pyproject_content)
+        self.reset_poetry()
 
-        if no_install:
-            # update lock file
-            self.call(name="lock", args="--no-update")
-            return 0
-
-        # update dependencies
-        self.call(name="update")
+        try:
+            if no_install:
+                # update lock file
+                self.call(name="lock", args="--no-update")
+            else:
+                # update dependencies
+                self.call(name="update")
+        except Exception as e:
+            self.line("\nReverting <comment>pyproject.toml</>")
+            self.poetry.file.write(original_pyproject_content)
+            raise e
         return 0
 
     def get_groups(self) -> Iterable[DependencyGroup]:

tests/e2e/test_e2e.py

@@ -22,6 +22,10 @@ def test_command(
         "poetry.version.version_selector.VersionSelector.find_best_candidate",
         side_effect=packages,
     )
+    mocker.patch(
+        "poetry.console.commands.installer_command.InstallerCommand.reset_poetry",  # noqa: E501
+        return_value=None,
+    )
 
     path = project_path / "expected_pyproject.toml"
     expected = PyProjectTOML(path).file.read()
@@ -46,6 +50,10 @@ def test_command_with_latest(
         "poetry.version.version_selector.VersionSelector.find_best_candidate",
         side_effect=packages,
     )
+    mocker.patch(
+        "poetry.console.commands.installer_command.InstallerCommand.reset_poetry",  # noqa: E501
+        return_value=None,
+    )
 
     path = project_path / "expected_pyproject_with_latest.toml"
     expected = PyProjectTOML(path).file.read()
@@ -69,6 +77,10 @@ def test_command_with_dry_run(
         "poetry.version.version_selector.VersionSelector.find_best_candidate",
         side_effect=packages,
     )
+    mocker.patch(
+        "poetry.console.commands.installer_command.InstallerCommand.reset_poetry",  # noqa: E501
+        return_value=None,
+    )
 
     expected = PyProjectTOML(tmp_pyproject_path).file.read()
 
@@ -93,10 +105,40 @@ def test_command_with_no_install(
         "poetry.version.version_selector.VersionSelector.find_best_candidate",
         side_effect=packages,
     )
+    mocker.patch(
+        "poetry.console.commands.installer_command.InstallerCommand.reset_poetry",  # noqa: E501
+        return_value=None,
+    )
 
     path = project_path / "expected_pyproject.toml"
     expected = PyProjectTOML(path).file.read()
 
     assert app_tester.execute("up --no-install") == 0
     assert PyProjectTOML(tmp_pyproject_path).file.read() == expected
     command_call.assert_called_once_with(name="lock", args="--no-update")
+
+
+def test_command_reverts_pyproject_on_error(
+    app_tester: ApplicationTester,
+    packages: List[Package],
+    mocker: MockerFixture,
+    tmp_pyproject_path: Path,
+) -> None:
+    command_call = mocker.patch(
+        "poetry.console.commands.command.Command.call",
+        side_effect=Exception,
+    )
+    mocker.patch(
+        "poetry.version.version_selector.VersionSelector.find_best_candidate",
+        side_effect=packages,
+    )
+    mocker.patch(
+        "poetry.console.commands.installer_command.InstallerCommand.reset_poetry",  # noqa: E501
+        return_value=None,
+    )
+
+    expected = PyProjectTOML(tmp_pyproject_path).file.read()
+
+    assert app_tester.execute("up") == 1
+    assert PyProjectTOML(tmp_pyproject_path).file.read() == expected
+    command_call.assert_called_once_with(name="update")