pyproject.toml: 3. Add pyside6-project tests for pyproject.toml changes

This patch adds tests for the pyside6-project CLI tool to validate the
pyproject.toml changes.

The tests ensure that the existing behavior is preserved and that the
new features work as expected.

Task-number: PYSIDE-2714
Change-Id: I096188c1d6d931a3970787f2906b83d2a987f4ed
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

26 files changed, 525 insertions, 56 deletions

diff --git a/sources/pyside6/tests/tools/pyside6-project/example_drumpad/Python/.pyproject b/sources/pyside6/tests/tools/pyside6-project/example_drumpad/Python/Drumpad.pyproject
index a5f654c2b..a5f654c2b 100644
--- a/sources/pyside6/tests/tools/pyside6-project/example_drumpad/Python/.pyproject
+++ b/sources/pyside6/tests/tools/pyside6-project/example_drumpad/Python/Drumpad.pyproject
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_drumpad/Python/pyproject.toml b/sources/pyside6/tests/tools/pyside6-project/example_drumpad/Python/pyproject.toml
new file mode 100644
index 000000000..3eeb1a90d
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_drumpad/Python/pyproject.toml
@@ -0,0 +1,5 @@
+[project]
+name = "Drumpad"
+
+[tool.pyside6-project]
+files = ["autogen/settings.py", "main.py"]
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/example_project.pyproject b/sources/pyside6/tests/tools/pyside6-project/example_project/example_project.pyproject
new file mode 100644
index 000000000..08fa3eac3
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/example_project.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["mainwindow.py", "my_widget.py", "folder/file_in_folder.py", "main.py", "subproject/subproject.pyproject"]
+}
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/folder/label_in_folder.py b/sources/pyside6/tests/tools/pyside6-project/example_project/folder/label_in_folder.py
new file mode 100644
index 000000000..ea3a6f5a1
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/folder/label_in_folder.py
@@ -0,0 +1,9 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+from PySide6.QtWidgets import QLabel
+
+
+class LabelInFolder(QLabel):
+    def __init__(self):
+        super().__init__()
+        self.setText("Label in folder")
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/main.py b/sources/pyside6/tests/tools/pyside6-project/example_project/main.py
new file mode 100644
index 000000000..0f7f96747
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/main.py
@@ -0,0 +1,20 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+import os
+
+from mainwindow import MainWindow
+from PySide6.QtWidgets import QApplication
+import sys
+
+
+def main():
+    app = QApplication(sys.argv)
+    window = MainWindow()
+    if os.getenv("PYSIDE_TESTING"):
+        return 0
+    window.show()
+    return app.exec()
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/mainwindow.py b/sources/pyside6/tests/tools/pyside6-project/example_project/mainwindow.py
new file mode 100644
index 000000000..fc259c6be
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/mainwindow.py
@@ -0,0 +1,22 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+from PySide6.QtWidgets import QMainWindow, QWidget, QVBoxLayout
+from folder.label_in_folder import LabelInFolder
+from subproject.subproject_button import SubprojectButton
+
+
+class MainWindow(QMainWindow):
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setWindowTitle("Main Window")
+
+        self.central_layout = QVBoxLayout()
+        self.central_widget = QWidget()
+        self.setCentralWidget(self.central_widget)
+        self.central_widget.setLayout(self.central_layout)
+
+        self.label_in_folder = LabelInFolder()
+        self.central_layout.addWidget(self.label_in_folder)
+
+        self.subproject_button = SubprojectButton()
+        self.central_layout.addWidget(self.subproject_button)
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/pyproject.toml b/sources/pyside6/tests/tools/pyside6-project/example_project/pyproject.toml
new file mode 100644
index 000000000..59cc29263
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/pyproject.toml
@@ -0,0 +1,5 @@
+[project]
+name = "example_project"
+
+[tool.pyside6-project]
+files = ["folder/file_in_folder.py", "main.py", "mainwindow.py", "my_widget.py", "subproject/subproject.pyproject"]
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/pyproject.toml b/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/pyproject.toml
new file mode 100644
index 000000000..1ceb0ac0b
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/pyproject.toml
@@ -0,0 +1,5 @@
+[project]
+name = "subproject"
+
+[tool.pyside6-project]
+files = ["subproject_button.py"]
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/subproject.pyproject b/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/subproject.pyproject
new file mode 100644
index 000000000..abfa1f461
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/subproject.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["subproject_button.py"]
+}
diff --git a/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/subproject_button.py b/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/subproject_button.py
new file mode 100644
index 000000000..40813ff86
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/example_project/subproject/subproject_button.py
@@ -0,0 +1,17 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+from PySide6.QtWidgets import QPushButton, QApplication
+import sys
+
+
+class SubprojectButton(QPushButton):
+    def __init__(self):
+        super().__init__()
+        self.setText("Subproject button")
+
+
+if __name__ == "__main__":
+    app = QApplication(sys.argv)
+    button = SubprojectButton()
+    button.show()
+    sys.exit(app.exec())
diff --git a/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/existing_pyproject_toml.pyproject b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/existing_pyproject_toml.pyproject
new file mode 100644
index 000000000..7ddbd86fd
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/existing_pyproject_toml.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["zzz.py", "main.py"]
+}
diff --git a/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/expected_pyproject.toml b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/expected_pyproject.toml
new file mode 100644
index 000000000..be8aa949f
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/expected_pyproject.toml
@@ -0,0 +1,22 @@
+[project]
+name = "my_project"
+version = "0.1.0"
+description = "A sample Python project"
+authors = [
+    { name = "John Doe", email = "john.doe@example.com" },
+]
+optional-dependencies = { dev = ["pytest", "black"], docs = ["sphinx"] }
+
+# Comment
+
+[tool.black]
+line-length = 88
+target-version = ["py38"]
+
+# Another comment
+
+[tool.pyside6-project]
+files = ["main.py", "zzz.py"]
+[build-system]
+requires = ["setuptools >=42"]
+build-backend = "setuptools.build_meta"
diff --git a/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/main.py b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/main.py
new file mode 100644
index 000000000..8d4c96674
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/main.py
@@ -0,0 +1,2 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
diff --git a/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/pyproject.toml b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/pyproject.toml
new file mode 100644
index 000000000..ce2656502
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/pyproject.toml
@@ -0,0 +1,20 @@
+[project]
+name = "my_project"
+version = "0.1.0"
+description = "A sample Python project"
+authors = [
+    { name = "John Doe", email = "john.doe@example.com" },
+]
+optional-dependencies = { dev = ["pytest", "black"], docs = ["sphinx"] }
+
+# Comment
+
+[tool.black]
+line-length = 88
+target-version = ["py38"]
+
+# Another comment
+
+[build-system]
+requires = ["setuptools >=42"]
+build-backend = "setuptools.build_meta"
diff --git a/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/zzz.py b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/zzz.py
new file mode 100644
index 000000000..8d4c96674
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/existing_pyproject_toml/zzz.py
@@ -0,0 +1,2 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
diff --git a/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/invalid_pyproject.pyproject b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/invalid_pyproject.pyproject
new file mode 100644
index 000000000..6d6e84a36
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/invalid_pyproject.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["main.py", 33]
+}
diff --git a/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/main.py b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/main.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/main.py
diff --git a/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/pyproject.toml b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/pyproject.toml
new file mode 100644
index 000000000..37d23c948
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/pyproject.toml
@@ -0,0 +1,2 @@
+this is not a valid pyproject.toml file
+because it does not have a valid toml structure
diff --git a/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/valid_pyproject.pyproject b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/valid_pyproject.pyproject
new file mode 100644
index 000000000..cc7a74a34
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/invalid_pyproject/valid_pyproject.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["main.py"]
+}
diff --git a/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/common_file.py b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/common_file.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/common_file.py
diff --git a/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/expected_pyproject.toml b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/expected_pyproject.toml
new file mode 100644
index 000000000..fda48f5ba
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/expected_pyproject.toml
@@ -0,0 +1,5 @@
+[project]
+name = "multiple_pyproject"
+
+[tool.pyside6-project]
+files = ["common_file.py", "file1.py", "file2.py"]
diff --git a/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/file1.py b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/file1.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/file1.py
diff --git a/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/file2.py b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/file2.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/file2.py
diff --git a/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/project1.pyproject b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/project1.pyproject
new file mode 100644
index 000000000..105f6f919
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/project1.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["file1.py", "common_file.py"]
+}
diff --git a/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/project2.pyproject b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/project2.pyproject
new file mode 100644
index 000000000..623b08794
--- /dev/null
+++ b/sources/pyside6/tests/tools/pyside6-project/multiple_pyproject/project2.pyproject
@@ -0,0 +1,3 @@
+{
+    "files": ["common_file.py", "file2.py"]
+}
diff --git a/sources/pyside6/tests/tools/pyside6-project/test_pyside6_project.py b/sources/pyside6/tests/tools/pyside6-project/test_pyside6_project.py
index 0e7982a53..d66395251 100644
--- a/sources/pyside6/tests/tools/pyside6-project/test_pyside6_project.py
+++ b/sources/pyside6/tests/tools/pyside6-project/test_pyside6_project.py
@@ -1,16 +1,18 @@
 # Copyright (C) 2024 The Qt Company Ltd.
 # SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 import contextlib
+import difflib
+import importlib
 import io
 import os
 import shutil
 import sys
-import unittest
-from unittest import mock
-from unittest import TestCase
 import tempfile
-import importlib
+import unittest
 from pathlib import Path
+from unittest import TestCase
+from unittest import mock
+from unittest.mock import patch
 
 sys.path.append(str(Path(__file__).resolve().parents[2]))
 from init_paths import init_test_paths
@@ -18,11 +20,30 @@ from init_paths import init_test_paths
 init_test_paths(False)
 
 
+def file_diff(expected_file: Path, actual_file: Path) -> str:
+    """
+    Get a unified diff between two files
+    """
+    target_text = expected_file.read_text(encoding="utf-8").splitlines()
+    generated_text = actual_file.read_text(encoding="utf-8").splitlines()
+
+    return "\n".join(difflib.unified_diff(
+        generated_text, target_text,
+        fromfile=str(actual_file),
+        tofile=str(expected_file),
+        lineterm=""
+    ))
+
+
 class PySide6ProjectTestBase(TestCase):
+    # If a project name is specified, on each the test, the project folder will be copy to the
+    # temp dir and the current dir will be changed to the project folder
+    # The project name must match an existing folder in the folder where this file is located
+    project_name: str | None = None
+
     @classmethod
     def setUpClass(cls):
         cls.pyside_root = Path(__file__).parents[5].resolve()
-        cls.example_root = cls.pyside_root / "examples"
         tools_path = cls.pyside_root / "sources" / "pyside-tools"
         if tools_path not in sys.path:
             sys.path.append(str(tools_path))
@@ -32,36 +53,42 @@ class PySide6ProjectTestBase(TestCase):
         cls.current_dir = Path.cwd()
         # print no outputs to stdout
         sys.stdout = mock.MagicMock()
+        if cls.project_name:
+            cls.temp_project = Path(cls.temp_dir / cls.project_name).resolve()
+        os.chdir(cls.temp_dir)
+
+    def setUp(self):
+        super().setUp()
+        if self.project_name:
+            shutil.copytree(Path(__file__).parent / self.project_name, self.temp_project)
+            os.chdir(self.temp_project)
+
+    def tearDown(self):
+        super().tearDown()
+        if self.project_name:
+            os.chdir(self.temp_dir)
+            shutil.rmtree(self.temp_project)
 
     @classmethod
     def tearDownClass(cls):
         os.chdir(cls.current_dir)
         shutil.rmtree(cls.temp_dir)
 
-    def setUp(self):
-        os.chdir(self.temp_dir)
-
 
 class TestPySide6ProjectDesignStudio(PySide6ProjectTestBase):
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
-        example_drumpad = Path(__file__).parent / "example_drumpad"
-        cls.temp_example_drumpad = Path(
-            shutil.copytree(example_drumpad, cls.temp_dir / "drumpad")
-        ).resolve()
+    project_name = "example_drumpad"
 
     def testDrumpadExample(self):
         # This test compiles the .qrc file into a .py file and checks whether the compilation is
         # carried out only when required
-        compiled_resources_path = self.temp_example_drumpad / "Python" / "autogen" / "resources.py"
-        resources_path = self.temp_example_drumpad / "Drumpad.qrc"
-        requires_rebuild = self.project_lib.utils.requires_rebuild
+        compiled_resources_path = Path("Python") / "autogen" / "resources.py"
+        resources_path = Path("Drumpad.qrc")
 
+        requires_rebuild = self.project_lib.utils.requires_rebuild
+        pyproject_path = Path("Python") / "Drumpad.pyproject"
         self.assertFalse(compiled_resources_path.exists())
-
-        os.chdir(self.temp_example_drumpad / "Python")
-        self.project.main(mode="build")
+        self.assertTrue(pyproject_path.exists())
+        self.project.main(mode="build", project_path=pyproject_path)
 
         self.assertTrue(compiled_resources_path.exists())
         self.assertFalse(requires_rebuild([resources_path], compiled_resources_path))
@@ -72,59 +99,96 @@ class TestPySide6ProjectDesignStudio(PySide6ProjectTestBase):
 
         self.assertTrue(requires_rebuild([resources_path], compiled_resources_path))
 
-        self.project.main(mode="build")
+        self.project.main(mode="build", project_path=pyproject_path)
 
         self.assertFalse(requires_rebuild([resources_path], compiled_resources_path))
 
         # Refresh the modification timestamp of one of the resources files
-        list((self.temp_example_drumpad / "Resources").glob("*.txt"))[0].touch()
+        list((Path("Resources").glob("*.txt")))[0].touch()
         self.assertTrue(requires_rebuild([resources_path], compiled_resources_path))
 
-        self.project.main(mode="clean")
+        self.project.main(mode="clean", project_path=pyproject_path)
 
         self.assertFalse(compiled_resources_path.exists())
 
+    def testMigrateDrumpadExample(self):
+        # The pyproject.toml file already contains the expected output
+        expected_pyproject_toml = Path("Python") / "pyproject.toml"
+        expected_pyproject_toml.rename(expected_pyproject_toml.parent / "expected_pyproject.toml")
+        existing_pyproject = Path("Python") / "Drumpad.pyproject"
+
+        with self.assertRaises(SystemExit) as context:
+            with patch("builtins.input", return_value="y"):
+                self.project.main(mode="migrate-pyproject",
+                                  project_path=existing_pyproject.as_posix())
+
+        self.assertEqual(0, context.exception.code)
+        generated_pyproject_toml = Path("Python") / "pyproject.toml"
+        self.assertTrue(generated_pyproject_toml.exists())
+        diff = file_diff(expected_pyproject_toml, generated_pyproject_toml)
+        self.assertFalse(diff, f"Generated pyproject.toml does not match:\n{diff}")
+
 
 class TestPySide6ProjectNew(PySide6ProjectTestBase):
     def testNewUi(self):
+        test_project_path = self.temp_dir / "NewUiProject"
         with self.assertRaises(SystemExit) as context:
-            self.project.main(mode="new-ui", project_dir="TestProject")
-        test_project_path = Path("TestProject")
+            self.project.main(mode="new-ui", project_dir=test_project_path.as_posix())
+
         self.assertTrue((test_project_path / "pyproject.toml").exists())
         self.assertTrue((test_project_path / "mainwindow.ui").exists())
         self.assertTrue((test_project_path / "main.py").exists())
-        self.assertEqual(context.exception.code, 0)
+        self.assertEqual(0, context.exception.code)
         shutil.rmtree(test_project_path)
 
-    def testRaiseErrorOnExistingProject(self):
+    def testRaiseErrorOnExistingNonEmptyProject(self):
+        # Create a project twice to ensure that an error is raised
+        project_name = "TestProject"
         with self.assertRaises(SystemExit) as context:
-            self.project.main(mode="new-ui", project_dir="TestProject")
-        self.assertEqual(context.exception.code, 0)
+            self.project.main(mode="new-ui", project_dir=project_name)
+
+        self.assertEqual(0, context.exception.code)
+
         error_message = io.StringIO()
-        with self.assertRaises(SystemExit) as context, contextlib.redirect_stderr(error_message):
-            self.project.main(mode="new-ui", project_dir="TestProject")
-        self.assertEqual(context.exception.code, 1)
-        self.assertTrue(error_message.getvalue())  # some error message is printed
+        with self.assertRaises(SystemExit) as context:
+            with contextlib.redirect_stderr(error_message):
+                self.project.main(mode="new-ui", project_dir=project_name)
+
+        self.assertEqual(1, context.exception.code)
+        self.assertTrue(f"Can not create project at {project_name}: directory is not empty." in
+                        error_message.getvalue())
         shutil.rmtree(self.temp_dir / "TestProject")
 
+    def testRaiseErrorOnInvalidProjectName(self):
+        # Create a project with an empty project name
+        error_message = io.StringIO()
+        with self.assertRaises(SystemExit) as context:
+            with contextlib.redirect_stderr(error_message):
+                self.project.main(mode="new-ui", project_dir="asdf/?^%$#@!")
+
+        self.assertEqual(1, context.exception.code)
+        self.assertTrue("Invalid project name" in error_message.getvalue())
+
     def testNewQuick(self):
+        test_project_path = Path("QuickProject")
+
         with self.assertRaises(SystemExit) as context:
-            self.project.main(mode="new-quick", project_dir="TestProject")
-        test_project_path = Path("TestProject")
+            self.project.main(mode="new-quick", project_dir=str(test_project_path))
+
         self.assertTrue((test_project_path / "pyproject.toml").exists())
         self.assertTrue((test_project_path / "main.qml").exists())
         self.assertTrue((test_project_path / "main.py").exists())
-        self.assertEqual(context.exception.code, 0)
+        self.assertEqual(0, context.exception.code)
         shutil.rmtree(test_project_path)
 
     def testNewWidget(self):
+        project_dir = self.temp_dir / "inner_folder" / "another_folder" / "WidgetProject"
         with self.assertRaises(SystemExit) as context:
-            self.project.main(mode="new-widget", project_dir="TestProject")
-        test_project_path = Path("TestProject")
-        self.assertTrue((test_project_path / "pyproject.toml").exists())
-        self.assertTrue((test_project_path / "main.py").exists())
-        self.assertEqual(context.exception.code, 0)
-        shutil.rmtree(test_project_path)
+            self.project.main(mode="new-widget", project_dir=project_dir.as_posix())
+        self.assertTrue((project_dir / "pyproject.toml").exists())
+        self.assertTrue((project_dir / "main.py").exists())
+        self.assertEqual(0, context.exception.code)
+        shutil.rmtree(project_dir)
 
     def testRaiseErrorWhenNoProjectNameIsSpecified(self):
         mode = "new-widget"
@@ -135,25 +199,273 @@ class TestPySide6ProjectNew(PySide6ProjectTestBase):
         expected_msg = f"Error creating new project: {mode} requires a directory name or path"
         self.assertTrue(expected_msg in error_message.getvalue())
 
+    def testCreateProjectLegacyPyProjectFile(self):
+        project_path = Path("TestPyProjectJSON")
+        mode = "new-widget"
+        with self.assertRaises(SystemExit) as context:
+            self.project.main(mode=mode, project_dir=project_path.as_posix(), legacy_pyproject=True)
+        self.assertEqual(0, context.exception.code)
+        self.assertTrue((project_path / "main.py").exists())
+        self.assertTrue((project_path / f"{project_path.name}.pyproject").exists())
+
 
 class TestPySide6ProjectRun(PySide6ProjectTestBase):
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
-        example_widgets = cls.example_root / "widgets" / "widgets" / "tetrix"
-        cls.temp_example_tetrix = Path(
-            shutil.copytree(example_widgets, Path(cls.temp_dir) / "tetrix")
-        ).resolve()
-
-    def testRunEmptyProject(self):
-        project_folder = self.temp_dir / "TestProject"
+    project_name = "example_project"
+
+    def testRaiseErrorWhenRunningEmptyProject(self):
+        # Create a new empty project in the temp dir
+        project_folder = self.temp_dir / "empty_project"
         project_folder.mkdir()
         os.chdir(project_folder)
+
         error_message = io.StringIO()
-        with self.assertRaises(SystemExit) as context, contextlib.redirect_stderr(error_message):
+        with self.assertRaises(SystemExit) as context:
+            with contextlib.redirect_stderr(error_message):
+                self.project.main(mode="run")
+
+        os.chdir(self.temp_dir)
+        shutil.rmtree(project_folder)
+
+        self.assertEqual(1, context.exception.code)
+        self.assertTrue("No project file found" in error_message.getvalue())
+
+    def testRunExampleProject(self):
+        # The project is executed in a subprocess. The proejct code reads the PYSIDE_TESTING
+        # environment variable to avoid starting the Qt event loop
+        os.environ["PYSIDE_TESTING"] = "1"
+        with self.assertRaises(SystemExit) as context:
             self.project.main(mode="run")
-        self.assertEqual(context.exception.code, 1)
-        self.assertTrue(error_message.getvalue())  # some error message is printed
+        os.environ.pop("PYSIDE_TESTING")
+        self.assertEqual(0, context.exception.code)
+
+        self.assertEqual(Path("pyproject.toml").resolve(),
+                         self.project_lib.resolve_valid_project_file())
+
+
+class TestPySide6ProjectExampleProject(PySide6ProjectTestBase):
+    """
+    Test of an example project with both pyproject.toml and .pyproject valid files.
+    Contains a subproject with its own pyproject.toml file and .pyproject file too
+    """
+    project_name = "example_project"
+
+    def testMigratePyProjectToToml(self):
+        # The existing pyproject.toml file contains the expected output
+        expected_pyproject_toml = Path("pyproject.toml").rename("expected_pyproject.toml")
+        expected_subproject_pyproject_toml = Path("subproject") / "pyproject.toml"
+        expected_subproject_pyproject_toml.rename(
+            expected_subproject_pyproject_toml.parent / "expected_subproject_pyproject.toml")
+
+        with self.assertRaises(SystemExit) as context:
+            self.project.main(mode="migrate-pyproject")
+
+        self.assertEqual(0, context.exception.code)
+
+        generated_pyproject_toml = Path("pyproject.toml")
+        self.assertTrue(generated_pyproject_toml.exists())
+        diff = file_diff(expected_pyproject_toml, generated_pyproject_toml)
+        self.assertFalse(diff, f"Generated pyproject.toml does not match:\n{diff}")
+
+        generated_subproject_pyproject_toml = Path("subproject") / "pyproject.toml"
+        self.assertTrue(generated_subproject_pyproject_toml.exists())
+        diff = file_diff(expected_subproject_pyproject_toml, generated_subproject_pyproject_toml)
+        self.assertFalse(diff, f"Generated subproject/pyproject.toml does not match:\n{diff}")
+
+    def testMigratePyProjectToTomlSpecifyingPyProjectFile(self):
+        # The existing pyproject.toml file contains the expected output
+        existing_pyproject = Path("example_project.pyproject")
+        expected_pyproject_toml = Path("pyproject.toml")
+        expected_pyproject_toml.rename("example_project.toml")
+
+        expected_subproject_pyproject_toml = Path("subproject") / "pyproject.toml"
+        expected_subproject_pyproject_toml.rename(
+            expected_subproject_pyproject_toml.parent / "expected_pyproject.toml")
+
+        with self.assertRaises(SystemExit) as context:
+            with patch("builtins.input", return_value="y"):
+                self.project.main(mode="migrate-pyproject",
+                                  project_path=existing_pyproject.as_posix())
+
+        self.assertEqual(0, context.exception.code)
+
+        generated_pyproject_toml = Path("pyproject.toml")
+        self.assertTrue(generated_pyproject_toml.exists())
+        diff = file_diff(expected_pyproject_toml, generated_pyproject_toml)
+        self.assertFalse(diff, f"Generated pyproject.toml does not match:\n{diff}")
+
+        generated_subproject_pyproject_toml = Path("subproject") / "pyproject.toml"
+        self.assertTrue(generated_subproject_pyproject_toml.exists())
+        diff = file_diff(expected_subproject_pyproject_toml, generated_subproject_pyproject_toml)
+        self.assertFalse(diff, f"Generated subproject/pyproject.toml does not match:\n{diff}")
+
+
+class TestPySide6ProjectExistingPyProjectToml(PySide6ProjectTestBase):
+    """
+    Test for migrating a project with an existing pyproject.toml file which does not contain the
+    [tool.pyside6-project] section
+    """
+    project_name = "existing_pyproject_toml"
+
+    def testMigratePyProjectToTomlAlreadyExistingTomlFile(self):
+        with self.assertRaises(SystemExit) as context:
+            with patch("builtins.input", return_value="y"):
+                self.project.main(mode="migrate-pyproject")
+
+        self.assertEqual(0, context.exception.code)
+        diff = file_diff(Path("expected_pyproject.toml"),
+                         Path("pyproject.toml"))
+        self.assertFalse(diff, f"Updated pyproject.toml does not match:\n{diff}")
+
+
+class TestPySide6ProjectInvalidPyProjectToml(PySide6ProjectTestBase):
+    """
+    Check the current behavior in a project with an existing invalid pyproject.toml file and
+    invalid_pyproject.pyproject file
+    """
+
+    project_name = "invalid_pyproject"
+
+    def testRunInvalidPyProjectTomlFile(self):
+        pyproject_toml = Path("pyproject.toml")
+        self.assertTrue(pyproject_toml.exists())
+        self.assertTrue(self.project_lib.parse_pyproject_toml(pyproject_toml).errors)
+
+        error_message = io.StringIO()
+        with contextlib.redirect_stderr(error_message):
+            with self.assertRaises(SystemExit) as context:
+                self.project.main(mode="run", project_path=pyproject_toml.as_posix())
+
+        self.assertEqual(1, context.exception.code)
+        self.assertTrue("Invalid project file" in error_message.getvalue())
+
+    def testRunSpecifyingPyProjectJsonFile(self):
+        # Check that the *.pyproject file is used if the pyproject.toml is invalid when using
+        # pyside6-project run
+
+        pyproject_toml_file = Path("pyproject.toml")
+        self.assertTrue(pyproject_toml_file.exists())
+        # Ensure that pyproject.toml is considered invalid
+        self.assertTrue(self.project_lib.parse_pyproject_toml(pyproject_toml_file).errors)
+
+        valid_pyproject = Path("valid_pyproject.pyproject")
+        self.assertTrue(valid_pyproject.exists())
+
+        # Ensure that the project can still be run specifying a valid *.pyproject JSON file
+        with self.assertRaises(SystemExit) as context:
+            self.project.main(mode="run", project_path=valid_pyproject.as_posix())
+
+        self.assertEqual(0, context.exception.code)
+        self.assertTrue(Path("main.py").exists())
+
+    def testErrorRaisesWhenRunningWithoutSpecifyingProjectFile(self):
+        # The project folder contains two *.pyproject JSON files.
+        # The tool should raise an error because the project file is not specified
+        error_message = io.StringIO()
+        with contextlib.redirect_stderr(error_message):
+            with self.assertRaises(SystemExit) as context:
+                self.project.main(mode="run")
+        self.assertEqual(1, context.exception.code)
+        self.assertTrue("Multiple project files found" in error_message.getvalue())
+
+    def testRaiseErrorResolvingInvalidProjectFile(self):
+        # Simulate that the user is specifying an invalid project file
+        invalid_pyproject_file = Path("invalid_pyproject.pyproject")
+        self.assertTrue(invalid_pyproject_file.exists())
+
+        with self.assertRaises(ValueError) as context:
+            self.project_lib.resolve_valid_project_file(invalid_pyproject_file.as_posix())
+
+        exception_message = str(context.exception)
+        self.assertTrue("Invalid project file" in exception_message)
+        self.assertTrue(str(invalid_pyproject_file) in exception_message)
+
+    def testResolveValidProjectFile(self):
+        # Simulate that the user is specifying a valid project file
+        valid_pyproject_file = Path("valid_pyproject.pyproject")
+        actual_project_file = self.project_lib.resolve_valid_project_file(
+            valid_pyproject_file.as_posix())
+        self.assertEqual(valid_pyproject_file.resolve(), actual_project_file)
+
+    def testRaiseErrorResolvingInvalidPyProjectToml(self):
+        # Simulate that the user is specifying an invalid pyproject.toml file
+        pyproject_toml_file = Path("pyproject.toml")
+        self.assertTrue(pyproject_toml_file.exists())
+
+        with self.assertRaises(ValueError) as context:
+            self.project_lib.resolve_valid_project_file(pyproject_toml_file.as_posix())
+
+        exception_message = str(context.exception)
+        self.assertTrue("Invalid project file" in exception_message)
+        self.assertTrue(str(pyproject_toml_file) in exception_message)
+
+    def testMigrateInvalidPyProjectToml(self):
+        # Can not migrate a project with an invalid pyproject.toml file
+        error_message = io.StringIO()
+        with contextlib.redirect_stderr(error_message):
+            with self.assertRaises(SystemExit) as context:
+                with patch("builtins.input", return_value="y"):
+                    self.project.main(mode="migrate-pyproject")
+
+        self.assertEqual(1, context.exception.code)
+        self.assertTrue("Invalid project file" in error_message.getvalue())
+
+    def testMigrateInvalidPyProjectTomlSpecifyingWrongFile(self):
+        # Test specifying the pyproject.toml file as the project file to be migrated
+        existing_invalid_pyproject_toml = Path("pyproject.toml")
+        self.assertTrue(
+            bool(self.project_lib.parse_pyproject_toml(existing_invalid_pyproject_toml).errors))
+
+        error_message = io.StringIO()
+        with contextlib.redirect_stderr(error_message):
+            with self.assertRaises(SystemExit) as context:
+                self.project.main(mode="migrate-pyproject",
+                                  project_path=existing_invalid_pyproject_toml)
+
+        self.assertEqual(1, context.exception.code)
+        self.assertTrue("Cannot migrate non \"*.pyproject\" file" in error_message.getvalue())
+        self.assertTrue("pyproject.toml" in error_message.getvalue())
+
+
+def testRunInvalidPyProjectToml(self):
+    # Ensure that the .pyproject file is preferred over the invalid pyproject.toml file.
+    # This preserves the backward compatibility of the .pyproject file
+
+    # Remove the invalid invalid_pyproject.pyproject file first
+    Path("invalid_pyproject.pyproject").unlink()
+    self.assertFalse(Path("invalid_pyproject.pyproject").exists())
+
+    with self.assertRaises(SystemExit) as context:
+        self.project.main(mode="run")
+
+    self.assertEqual(0, context.exception.code)
+    self.assertEqual(Path("valid_pyproject.pyproject").resolve(),
+                     self.project_lib.resolve_valid_project_file())
+
+
+class TestPySide6ProjectMultiplePyProject(PySide6ProjectTestBase):
+    project_name = "multiple_pyproject"
+
+    def testCancelMigration(self):
+        # Ensure that the pyproject.toml is not created if the user cancels the operation
+        with self.assertRaises(SystemExit) as context:
+            with patch("builtins.input", return_value="n"):
+                self.project.main(mode="migrate-pyproject")
+
+        self.assertEqual(0, context.exception.code)
+        self.assertFalse(Path("pyproject.toml").exists())
+
+    def testMigrateMultiplePyProjectFilesToToml(self):
+        expected_pyproject_toml = Path("expected_pyproject.toml")
+        generated_pyproject_toml = Path("pyproject.toml")
+
+        with self.assertRaises(SystemExit) as context:
+            with patch("builtins.input", return_value="y"):
+                self.project.main(mode="migrate-pyproject")
+
+        self.assertEqual(0, context.exception.code)
+        self.assertTrue(generated_pyproject_toml.exists())
+        diff = file_diff(expected_pyproject_toml, generated_pyproject_toml)
+        self.assertFalse(diff, f"Generated pyproject.toml does not match:\n{diff}")
 
 
 if __name__ == "__main__":