fix(init): allow long directory names

snapcraft/services/init.py

@@ -32,23 +32,30 @@ class Init(services.InitService):
     """Service class for initializing a project."""
 
     @override
-    def initialise_project(
-        self,
-        *,
-        project_dir: pathlib.Path,
-        project_name: str,
-        template_dir: pathlib.Path,
-    ) -> None:
+    def validate_project_name(self, name: str, *, use_default: bool = False) -> str:
+        """Validate that ``name`` is valid as a snap name."""
         try:
-            validate_name(name=project_name, field_name="snap")
-            if len(project_name) > 40:
+            validate_name(name=name, field_name="snap")
+            if len(name) > 40:
                 raise ValueError("snap names must be 40 characters or less")
         except ValueError as err:
+            if use_default:
+                return self._default_name
             raise errors.SnapcraftError(
-                message=f"Invalid snap name {project_name!r}: {str(err)}.",
+                message=f"Invalid snap name {name!r}: {str(err)}.",
                 resolution="Provide a valid name with '--name' or rename the project directory.",
             ) from err
 
+        return name
+
+    @override
+    def initialise_project(
+        self,
+        *,
+        project_dir: pathlib.Path,
+        project_name: str,
+        template_dir: pathlib.Path,
+    ) -> None:
         super().initialise_project(
             project_dir=project_dir,
             project_name=project_name,

tests/unit/commands/test_init.py

@@ -102,6 +102,24 @@ def test_init_default(profile, name, project_dir, emitter, valid_new_dir, mocker
     emitter.assert_message("Successfully initialised project.")
 
 
+def test_init_default_long_directory_name(emitter, tmp_path, monkeypatch, mocker):
+    """Use the default project name when the directory name is too long."""
+    new_dir = tmp_path / "this-working-directory-has-a-very-long-name"
+    new_dir.mkdir()
+    monkeypatch.chdir(new_dir)
+    snapcraft_yaml = new_dir / "snap/snapcraft.yaml"
+    mocker.patch.object(sys, "argv", _create_command())
+
+    app = application.create_app()
+    app.run()
+
+    assert snapcraft_yaml.exists()
+    data = apply_yaml(process_yaml(snapcraft_yaml), "amd64", "amd64")
+    project = Project.unmarshal(data)
+    assert project.name == "my-project"
+    emitter.assert_message("Successfully initialised project.")
+
+
 @pytest.mark.parametrize("yaml_content", ["", "just a string"])
 def test_init_existing_yaml_invalid(yaml_content, emitter, valid_new_dir, mocker):
     """Test the 'snapcraft init' command with existing empty/invalid snapcraft.yaml."""

tests/unit/services/test_init.py

@@ -82,16 +82,19 @@ def test_init_valid_name(name, init_service, new_dir, emitter):
         ),
     ],
 )
-def test_init_invalid_name(name, error, init_service, new_dir):
-    """Error on invalid names."""
+def test_validate_project_name_invalid_name(name, error, init_service):
+    """Error on invalid snap names."""
     expected_error = f"Invalid snap name {name!r}: {error}."
 
     with pytest.raises(errors.SnapcraftError, match=expected_error):
-        init_service.initialise_project(
-            project_dir=new_dir,
-            project_name=name,
-            template_dir=template_dir(),
-        )
+        init_service.validate_project_name(name)
+
+
+def test_validate_project_name_uses_default_for_long_directory_name(init_service):
+    """Use the default name when the project directory name is too long."""
+    name = "a2345678901234567890123456789012345678901"
+
+    assert init_service.validate_project_name(name, use_default=True) == "my-project"
 
 
 def test_init_snap_dir_exists(init_service, new_dir, emitter):