Validate user input from init command

src/poetry/console/commands/init.py

@@ -16,6 +16,7 @@
 
 from poetry.console.commands.command import Command
 from poetry.console.commands.env_command import EnvCommand
+from poetry.factory import Factory
 from poetry.utils.dependency_specification import RequirementsParser
 from poetry.utils.env.python import Python
 
@@ -268,6 +269,16 @@ def _init_pyproject(
 
             return 1
 
+        # Validate fields before creating pyproject.toml file. If any validations fail, throw an error.
+        validation_results = Factory().validate(pyproject.data)
+        if validation_results.get("errors"):
+            message = ""
+            for error in validation_results.get("errors", []):
+                message += f"  - {error}\n"
+
+            self.line_error(f"Validation failed: \n{message}")
+            return 1
+
         pyproject.save()
 
         if create_layout:

tests/console/commands/test_init.py

@@ -918,7 +918,7 @@
 """
     pyproject_file.write_text(existing_section, encoding="utf-8")
     tester.execute(inputs=init_basic_inputs)
     assert f"{existing_section}\n{init_basic_toml}" in pyproject_file.read_text(
         encoding="utf-8"
     )
 
@@ -942,7 +942,7 @@
     with open(pyproject_file, newline="", encoding="utf-8") as f:
         content = f.read()
     init_basic_toml = init_basic_toml.replace("\n", linesep)
     assert f"{existing_section}{linesep}{init_basic_toml}" in content
 
 
 def test_init_non_interactive_existing_pyproject_add_dependency(
@@ -982,7 +982,7 @@
     "foo (>=1.19.2,<2.0.0)"
 ]
 """
     assert f"{existing_section}\n{expected}" in pyproject_file.read_text(
         encoding="utf-8"
     )
 
@@ -1207,3 +1207,32 @@
     # Existing files should remain
     assert (source_dir / "existing_file.txt").exists()
     assert (source_dir / "existing_dir").exists()
+
+
+def test_noninteractive_validation_shows_error(
+    app: PoetryTestApplication, mocker: MockerFixture
+) -> None:
+    command = app.find("init")
+    assert isinstance(command, InitCommand)
+
+    expected_error = r"Validation failed: \n  - project.name must match pattern ^([a-zA-Z\d]|[a-zA-Z\d][\w.-]*[a-zA-Z\d])$"
+
+    # Set Factory.validate to return a mocked error message
+    # We mock Factory.validate() because this test focuses on _init_pyproject(), not on the validation logic itself.
+    mocked_validate = mocker.patch(
+        "poetry.console.commands.init.Factory.validate",
+        return_value={"errors": [expected_error]},
+    )
+
+    init_tester = CommandTester(command)
+    args = '--name "new project"'
+    result = init_tester.execute(args=args, interactive=False)
+
+    # Check that the command fails
+    assert result == 1
+
+    error_output = init_tester.io.fetch_error()
+    assert expected_error in error_output
+
+    # Verify that validate() was called
+    mocked_validate.assert_called_once()