Use the Python attrs library + improve output on errors

cmake_pc_hooks/_call_process.py

@@ -20,19 +20,26 @@
 import subprocess as sp
 import sys
 
+import attrs
 
+
+@attrs.define(slots=True)
 class History:  # pylint: disable=too-few-public-methods
     """Process execution data."""
 
-    __slots__ = ('stdout', 'stderr', 'returncode')
+    stdout: str
+    stderr: str
+    returncode: int
+    _print_output: bool = True
 
-    def __init__(self, stdout, stderr, returncode):
-        self.stdout = stdout
-        self.stderr = stderr
-        self.returncode = returncode
+    def disable_print_output(self) -> None:
+        """Disable output printing."""
+        self._print_output = False
 
-    def to_stdout_and_stderr(self):
+    def to_stdout_and_stderr(self) -> None:
         """Copy the relevant content to the standard output and error streams."""
+        if not self._print_output:
+            return
         sys.stdout.write(self.stdout)
         sys.stdout.flush()
         sys.stderr.write(self.stderr)

cmake_pc_hooks/_utils.py

@@ -135,8 +135,8 @@ def run(self):
 
         has_errors = False
         for res in self.history:
-            res.to_stdout_and_stderr()
             has_errors |= self._parse_output(res)
+            res.to_stdout_and_stderr()
 
         if has_errors:
             sys.exit(1)

setup.cfg

@@ -26,6 +26,7 @@ install_requires =
     CLinters >= 1.3.0
     fasteners
     filelock
+    attrs >= 23
 
 [options.entry_points]
 console_scripts =

tests/python/_call_process_test.py

@@ -12,30 +12,36 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import pytest
 import subprocess as sp
 
 from cmake_pc_hooks._call_process import History, call_process
 
 # ==============================================================================
 
-
-def test_history(mocker):
+@pytest.parametrize('disable_print', [False, True])
+def test_history(mocker, disable_print):
     stdout = 'out'
     stderr = 'err'
     returncode = 1
     history = History(stdout=stdout, stderr=stderr, returncode=returncode)
+    if disable_print:
+        history.disable_print_output()
 
     assert history.stdout == stdout
     assert history.stderr == stderr
     assert history.returncode == returncode
 
     sys_stdout = mocker.patch('sys.stdout')
     sys_stderr = mocker.patch('sys.stderr')
-
     history.to_stdout_and_stderr()
 
-    sys_stdout.write.assert_called_once()
-    sys_stderr.write.assert_called_once()
+    if disable_print:
+        sys_stdout.write.assert_not_called()
+        sys_stderr.write.assert_not_called()
+    else:
+        sys_stdout.write.assert_called_once()
+        sys_stderr.write.assert_called_once()
 
 
 # ==============================================================================