Fix: relative -d/--project-dir path causes FileNotFoundError in device monitor

platformio/device/monitor/command.py

@@ -104,7 +104,7 @@
     "-d",
     "--project-dir",
     default=os.getcwd,
-    type=click.Path(exists=True, file_okay=False, dir_okay=True),
+    type=click.Path(exists=True, file_okay=False, dir_okay=True, resolve_path=True),
 )
 @click.option(
     "-e",

tests/commands/test_device_monitor.py

@@ -0,0 +1,99 @@
+# Copyright (c) 2014-present PlatformIO <contact@platformio.org>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+
+from platformio import fs
+from platformio.device.finder import SerialPortFinder
+from platformio.device.monitor.command import device_monitor_cmd
+
+
+def _patch_monitor_internals(monkeypatch, on_register_filters):
+    # `register_filters` is where a platform's monitor filter (e.g. the
+    # espressif32 exception decoder) re-enters `project_dir` via
+    # `fs.cd()`/`load_build_metadata()`. Stub the heavy, hardware-dependent
+    # collaborators so the command can run in CI while still exercising the
+    # real `project_dir` value it receives.
+    monkeypatch.setattr(
+        "platformio.device.monitor.command.register_filters", on_register_filters
+    )
+    monkeypatch.setattr(
+        "platformio.device.monitor.command.start_terminal", lambda options: None
+    )
+    monkeypatch.setattr(
+        SerialPortFinder, "find", lambda self, initial_port=None: "socket://localhost:0"
+    )
+
+
+def test_relative_project_dir_is_resolved_before_use(
+    clirunner, validate_cliresult, monkeypatch, tmpdir
+):
+    # Regression test for https://github.com/platformio/platformio-core/issues/5439
+    # `pio device monitor -d <relative-dir>` used to crash with a duplicated
+    # path (e.g. `.../examples/distance-ultrasound/examples/distance-ultrasound`)
+    # because `project_dir` stayed relative while the working directory had
+    # already been changed into it via `fs.cd()`.
+    project_dir = os.path.realpath(str(tmpdir.mkdir("project")))
+    captured = {}
+
+    def on_register_filters(platform, options):  # pylint: disable=unused-argument
+        captured["project_dir"] = options["project_dir"]
+        # Mirror `load_build_metadata()`, which re-enters `project_dir` via a
+        # second, nested `fs.cd()` while already inside the first one.
+        with fs.cd(options["project_dir"]):
+            captured["cwd_after_nested_cd"] = os.getcwd()
+
+    _patch_monitor_internals(monkeypatch, on_register_filters)
+    monkeypatch.chdir(tmpdir)
+
+    result = clirunner.invoke(device_monitor_cmd, ["-d", "project"])
+    validate_cliresult(result)
+
+    # compare against the realpath, not the raw tmpdir string: `resolve_path`
+    # also resolves symlinks, and some platforms put the temp dir behind one
+    # (e.g. macOS `/tmp` -> `/private/tmp`)
+    assert os.path.isabs(captured["project_dir"])
+    assert captured["project_dir"] == project_dir
+    assert captured["cwd_after_nested_cd"] == project_dir
+
+
+def test_default_project_dir_without_flag_still_absolute(
+    clirunner, validate_cliresult, monkeypatch, tmpdir
+):
+    captured = {}
+    _patch_monitor_internals(
+        monkeypatch,
+        lambda platform, options: captured.update(project_dir=options["project_dir"]),
+    )
+    monkeypatch.chdir(tmpdir)
+
+    result = clirunner.invoke(device_monitor_cmd, [])
+    validate_cliresult(result)
+
+    assert captured["project_dir"] == os.path.realpath(str(tmpdir))
+
+
+def test_absolute_project_dir_passthrough(
+    clirunner, validate_cliresult, monkeypatch, tmpdir
+):
+    captured = {}
+    _patch_monitor_internals(
+        monkeypatch,
+        lambda platform, options: captured.update(project_dir=options["project_dir"]),
+    )
+
+    result = clirunner.invoke(device_monitor_cmd, ["-d", str(tmpdir)])
+    validate_cliresult(result)
+
+    assert captured["project_dir"] == os.path.realpath(str(tmpdir))