tests: update config tests

- Add patched rootdir fixture to all config tests. I think this isn't strictly necessary but it does ensure that any config tests that need to write files don't accidentally write to user data locations.
- Be more careful when calling `get_config()` in the tests, by clearing the LRU cache before and after. This ensures a test doesn't reference the singleton config created by a previously run test.
- Add test for env var parsing.
- Add test for config writing in the context of `get_config()`. This is effectively a mini e2e test for the config lifecycle.

tests/test_config.py

@@ -6,7 +6,13 @@ import pytest
 from omegaconf import OmegaConf
 from pydantic import ValidationError
 
-from invokeai.app.services.config.config_default import InvokeAIAppConfig, get_config, load_and_migrate_config
+from invokeai.app.services.config.config_default import (
+    DefaultInvokeAIAppConfig,
+    InvokeAIAppConfig,
+    get_config,
+    load_and_migrate_config,
+)
+from invokeai.frontend.cli.arg_parser import InvokeAIArgs
 
 v4_config = """
 schema_version: 4.0.0
@@ -59,14 +65,14 @@ def patch_rootdir(tmp_path: Path, monkeypatch: Any) -> None:
     monkeypatch.setenv("INVOKEAI_ROOT", str(tmp_path))
 
 
-def test_path_resolution_root_not_set():
+def test_path_resolution_root_not_set(patch_rootdir: None):
     """Test path resolutions when the root is not explicitly set."""
     config = InvokeAIAppConfig()
     expected_root = InvokeAIAppConfig.find_root()
     assert config.root_path == expected_root
 
 
-def test_read_config_from_file(tmp_path: Path):
+def test_read_config_from_file(tmp_path: Path, patch_rootdir: None):
     """Test reading configuration from a file."""
     temp_config_file = tmp_path / "temp_invokeai.yaml"
     temp_config_file.write_text(v4_config)
@@ -76,7 +82,7 @@ def test_read_config_from_file(tmp_path: Path):
     assert config.port == 8080
 
 
-def test_migrate_v3_config_from_file(tmp_path: Path):
+def test_migrate_v3_config_from_file(tmp_path: Path, patch_rootdir: None):
     """Test reading configuration from a file."""
     temp_config_file = tmp_path / "temp_invokeai.yaml"
     temp_config_file.write_text(v3_config)
@@ -92,7 +98,7 @@ def test_migrate_v3_config_from_file(tmp_path: Path):
     assert not hasattr(config, "esrgan")
 
 
-def test_migrate_v3_backup(tmp_path: Path):
+def test_migrate_v3_backup(tmp_path: Path, patch_rootdir: None):
     """Test the backup of the config file."""
     temp_config_file = tmp_path / "temp_invokeai.yaml"
     temp_config_file.write_text(v3_config)
@@ -102,7 +108,7 @@ def test_migrate_v3_backup(tmp_path: Path):
     assert temp_config_file.with_suffix(".yaml.bak").read_text() == v3_config
 
 
-def test_failed_migrate_backup(tmp_path: Path):
+def test_failed_migrate_backup(tmp_path: Path, patch_rootdir: None):
     """Test the failed migration of the config file."""
     temp_config_file = tmp_path / "temp_invokeai.yaml"
     temp_config_file.write_text(v3_config_with_bad_values)
@@ -115,7 +121,7 @@ def test_failed_migrate_backup(tmp_path: Path):
     assert temp_config_file.read_text() == v3_config_with_bad_values
 
 
-def test_bails_on_invalid_config(tmp_path: Path):
+def test_bails_on_invalid_config(tmp_path: Path, patch_rootdir: None):
     """Test reading configuration from a file."""
     temp_config_file = tmp_path / "temp_invokeai.yaml"
     temp_config_file.write_text(invalid_config)
@@ -124,7 +130,7 @@ def test_bails_on_invalid_config(tmp_path: Path):
         load_and_migrate_config(temp_config_file)
 
 
-def test_bails_on_config_with_unsupported_version(tmp_path: Path):
+def test_bails_on_config_with_unsupported_version(tmp_path: Path, patch_rootdir: None):
     """Test reading configuration from a file."""
     temp_config_file = tmp_path / "temp_invokeai.yaml"
     temp_config_file.write_text(invalid_v5_config)
@@ -133,7 +139,7 @@ def test_bails_on_config_with_unsupported_version(tmp_path: Path):
         load_and_migrate_config(temp_config_file)
 
 
-def test_write_config_to_file():
+def test_write_config_to_file(patch_rootdir: None):
     """Test writing configuration to a file, checking for correct output."""
     with TemporaryDirectory() as tmpdir:
         temp_config_path = Path(tmpdir) / "invokeai.yaml"
@@ -148,7 +154,7 @@ def test_write_config_to_file():
             assert "port: 8080" in content
 
 
-def test_update_config_with_dict():
+def test_update_config_with_dict(patch_rootdir: None):
     """Test updating the config with a dictionary."""
     config = InvokeAIAppConfig()
     update_dict = {"host": "10.10.10.10", "port": 6060}
@@ -157,7 +163,7 @@ def test_update_config_with_dict():
     assert config.port == 6060
 
 
-def test_update_config_with_object():
+def test_update_config_with_object(patch_rootdir: None):
     """Test updating the config with another config object."""
     config = InvokeAIAppConfig()
     new_config = InvokeAIAppConfig(host="10.10.10.10", port=6060)
@@ -166,7 +172,7 @@ def test_update_config_with_object():
     assert config.port == 6060
 
 
-def test_set_and_resolve_paths():
+def test_set_and_resolve_paths(patch_rootdir: None):
     """Test setting root and resolving paths based on it."""
     with TemporaryDirectory() as tmpdir:
         config = InvokeAIAppConfig()
@@ -175,11 +181,62 @@ def test_set_and_resolve_paths():
         assert config.db_path == Path(tmpdir).resolve() / "databases" / "invokeai.db"
 
 
-def test_singleton_behavior():
+def test_singleton_behavior(patch_rootdir: None):
     """Test that get_config always returns the same instance."""
+    get_config.cache_clear()
     config1 = get_config()
     config2 = get_config()
     assert config1 is config2
+    get_config.cache_clear()
+
+
+def test_default_config(patch_rootdir: None):
+    """Test that the default config is as expected."""
+    config = DefaultInvokeAIAppConfig()
+    assert config.host == "127.0.0.1"
+
+
+def test_env_vars(patch_rootdir: None, monkeypatch: pytest.MonkeyPatch, tmp_path: Path):
+    """Test that environment variables are merged into the config"""
+    monkeypatch.setenv("INVOKEAI_ROOT", str(tmp_path))
+    monkeypatch.setenv("INVOKEAI_HOST", "1.2.3.4")
+    monkeypatch.setenv("INVOKEAI_PORT", "1234")
+    config = InvokeAIAppConfig()
+    assert config.host == "1.2.3.4"
+    assert config.port == 1234
+    assert config.root_path == tmp_path
+
+
+def test_get_config_writing(patch_rootdir: None, monkeypatch: pytest.MonkeyPatch, tmp_path: Path):
+    """Test that get_config writes the appropriate files to disk"""
+    # Trick the config into thinking it has already parsed args - this triggers the writing of the config file
+    InvokeAIArgs.did_parse = True
+
+    monkeypatch.setenv("INVOKEAI_ROOT", str(tmp_path))
+    monkeypatch.setenv("INVOKEAI_HOST", "1.2.3.4")
+    get_config.cache_clear()
+    config = get_config()
+    get_config.cache_clear()
+    config_file_path = tmp_path / "invokeai.yaml"
+    example_file_path = config_file_path.with_suffix(".example.yaml")
+    assert config.config_file_path == config_file_path
+    assert config_file_path.exists()
+    assert example_file_path.exists()
+
+    # The example file should have the default values
+    example_file_content = example_file_path.read_text()
+    assert "host: 127.0.0.1" in example_file_content
+    assert "port: 9090" in example_file_content
+
+    # It should also have the `remote_api_tokens` key
+    assert "remote_api_tokens" in example_file_content
+
+    # Neither env vars nor default values should be written to the config file
+    config_file_content = config_file_path.read_text()
+    assert "host" not in config_file_content
+
+    # Undo our change to the singleton class
+    InvokeAIArgs.did_parse = False
 
 
 @pytest.mark.xfail(
@@ -212,7 +269,9 @@ def test_deny_nodes(patch_rootdir):
         """
     )
     # must parse config before importing Graph, so its nodes union uses the config
+    get_config.cache_clear()
     conf = get_config()
+    get_config.cache_clear()
     conf.merge_from_file(conf=allow_deny_nodes_conf, argv=[])
     from invokeai.app.services.shared.graph import Graph