Implement rec - Phase 4 complete

tests/test_config_isolation.py

@@ -1,22 +1,12 @@
-"""Suite-wide isolation of `Settings` from developer environment files.
-
-`Settings.model_config` declares `env_file=".env.production"`, resolved relative to the
-current working directory. Running pytest from the repository root therefore loads a real
-developer env file into tests that construct `Settings(...)` directly, and the declared
-field defaults stop being what the suite actually exercises.
-
-That breaks verification in both directions: tests asserting default behavior fail locally
-for environmental reasons, and tests asserting configured behavior can pass locally against
-values that do not exist in CI. The autouse fixture in `conftest.py` neutralizes the class
-level `env_file` so defaults are authoritative; tests that need file loading still pass
-`_env_file=` explicitly, which takes precedence over the class config.
-"""
+"""Suite-wide isolation of `Settings` from developer environment files."""
 
 from __future__ import annotations
 
 from pathlib import Path
 
+import transcription.config as config_module
 from transcription.config import Settings
+from transcription.config import resolve_settings_env_file_path
 
 
 def test_settings_defaults_are_not_overridden_by_a_local_env_file():
@@ -37,3 +27,23 @@ def test_explicit_env_file_still_loads(tmp_path):
     settings = Settings(openrouter_api_key="test-key", _env_file=env_path, _cli_parse_args=False)
 
     assert settings.port == 9123
+
+
+def test_settings_env_file_resolves_from_override_environment_variable(tmp_path, monkeypatch):
+    env_path = tmp_path / "custom.env"
+    env_path.write_text("PORT=9123\n", encoding="utf-8")
+    monkeypatch.setenv("ENV_FILE", str(env_path))
+
+    settings = Settings(openrouter_api_key="test-key", _cli_parse_args=False)
+
+    assert settings.port == 9123
+
+
+def test_settings_default_env_path_is_anchored_to_project_root(tmp_path, monkeypatch):
+    monkeypatch.delenv("ENV_FILE", raising=False)
+    monkeypatch.chdir(tmp_path)
+    monkeypatch.setattr(config_module, "PROJECT_ROOT", tmp_path / "project-root")
+
+    resolved = resolve_settings_env_file_path()
+
+    assert resolved == tmp_path / "project-root" / ".env.production"