fix: reject powermetrics on non-Apple-Silicon Macs

codecarbon/core/powermetrics.py

@@ -118,17 +118,19 @@ def _setup_cli(self) -> None:
         """
         Setup cli command to run Powermetrics
         """
-        if self._system.startswith("darwin"):
-            cpu_model = detect_cpu_model()
-            if cpu_model.startswith("Apple"):
-                if shutil.which(self._osx_silicon_exec):
-                    self._cli = self._osx_silicon_exec
-                else:
-                    raise FileNotFoundError(
-                        f"Powermetrics executable not found on {self._system}"
-                    )
-        else:
+        if not self._system.startswith("darwin"):
             raise SystemError("Platform not supported by Powermetrics")
+        cpu_model = detect_cpu_model() or ""
+        if not cpu_model.startswith("Apple"):
+            raise SystemError(
+                "Powermetrics is only supported on Apple Silicon, "
+                f"detected CPU: {cpu_model!r}"
+            )
+        if not shutil.which(self._osx_silicon_exec):
+            raise FileNotFoundError(
+                f"Powermetrics executable not found on {self._system}"
+            )
+        self._cli = self._osx_silicon_exec
 
     def _log_values(self) -> None:
         """
@@ -140,10 +142,9 @@ def _log_values(self) -> None:
             # Run the powermetrics command with sudo and capture its output
             cmd = [
                 "sudo",
-                "powermetrics",
+                self._cli,
                 "-n",
                 str(self._n_points),
-                "",
                 "--samplers",
                 "cpu_power",
                 "--format",

tests/test_powermetrics.py

@@ -209,6 +209,40 @@ def test_setup_cli_raises_when_binary_missing_on_apple_silicon(self):
             with pytest.raises(FileNotFoundError):
                 ApplePowermetrics()
 
+    def test_setup_cli_raises_on_intel_mac(self):
+        with (
+            mock.patch("codecarbon.core.powermetrics.sys.platform", "darwin"),
+            mock.patch(
+                "codecarbon.core.powermetrics.detect_cpu_model",
+                return_value="Intel(R) Core(TM) i7-9750H",
+            ),
+        ):
+            with pytest.raises(SystemError):
+                ApplePowermetrics()
+
+    def test_setup_cli_raises_when_cpu_model_unknown(self):
+        with (
+            mock.patch("codecarbon.core.powermetrics.sys.platform", "darwin"),
+            mock.patch(
+                "codecarbon.core.powermetrics.detect_cpu_model", return_value=None
+            ),
+        ):
+            with pytest.raises(SystemError):
+                ApplePowermetrics()
+
+    def test_setup_cli_sets_cli_on_apple_silicon(self):
+        with (
+            mock.patch("codecarbon.core.powermetrics.sys.platform", "darwin"),
+            mock.patch(
+                "codecarbon.core.powermetrics.detect_cpu_model", return_value="Apple M2"
+            ),
+            mock.patch(
+                "codecarbon.core.powermetrics.shutil.which",
+                return_value="/usr/bin/powermetrics",
+            ),
+        ):
+            assert ApplePowermetrics()._cli == "powermetrics"
+
     def test_log_values_returns_none_on_non_darwin(self):
         powermetrics = ApplePowermetrics.__new__(ApplePowermetrics)
         powermetrics._system = "linux"
@@ -221,6 +255,7 @@ def test_log_values_warns_on_nonzero_returncode(self):
         powermetrics._n_points = 3
         powermetrics._interval = 100
         powermetrics._log_file_path = "powermetrics_log.txt"
+        powermetrics._cli = "powermetrics"
 
         with (
             mock.patch(
@@ -233,6 +268,23 @@ def test_log_values_warns_on_nonzero_returncode(self):
         mock_call.assert_called_once()
         mock_warning.assert_called_once()
 
+    def test_log_values_builds_clean_command(self):
+        powermetrics = ApplePowermetrics.__new__(ApplePowermetrics)
+        powermetrics._system = "darwin"
+        powermetrics._n_points = 3
+        powermetrics._interval = 100
+        powermetrics._log_file_path = "powermetrics_log.txt"
+        powermetrics._cli = "powermetrics"
+
+        with mock.patch(
+            "codecarbon.core.powermetrics.subprocess.call", return_value=0
+        ) as mock_call:
+            powermetrics._log_values()
+
+        cmd = mock_call.call_args.args[0]
+        assert "" not in cmd
+        assert cmd[1] == powermetrics._cli
+
     @mock.patch("codecarbon.core.powermetrics.ApplePowermetrics._log_values")
     @mock.patch("builtins.open", side_effect=OSError("missing"))
     @mock.patch("codecarbon.core.powermetrics.ApplePowermetrics._setup_cli")