Fix pydantic-settings validation for API key

Use validation_alias to allow OPENAI_API_KEY without TRANSCRIBE_ prefix.
Isolate tests from .env files with _env_file=None and clear=True.

Author: jmagly

src/transcribe_cli/config/settings.py

@@ -7,9 +7,9 @@
 """
 
 from pathlib import Path
-from typing import Literal, Optional
+from typing import Literal
 
-from pydantic import SecretStr, field_validator
+from pydantic import Field, SecretStr, field_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 
@@ -31,7 +31,8 @@ class Settings(BaseSettings):
     )
 
     # API Configuration (required, no default)
-    openai_api_key: SecretStr
+    # Uses OPENAI_API_KEY (no prefix) for compatibility with OpenAI conventions
+    openai_api_key: SecretStr = Field(validation_alias="OPENAI_API_KEY")
 
     # Output settings
     output_dir: Path = Path(".")

tests/unit/test_config.py

@@ -15,22 +15,20 @@ class TestSettings:
 
     def test_settings_loads_from_env(self) -> None:
         """Settings should load API key from environment variable."""
-        with patch.dict(os.environ, {"OPENAI_API_KEY": "sk-test-key"}):
-            settings = Settings()
+        with patch.dict(os.environ, {"OPENAI_API_KEY": "sk-test-key"}, clear=True):
+            settings = Settings(_env_file=None)
             assert settings.openai_api_key.get_secret_value() == "sk-test-key"
 
     def test_settings_requires_api_key(self) -> None:
         """Settings should raise error when API key is missing."""
         with patch.dict(os.environ, {}, clear=True):
-            # Remove any existing OPENAI_API_KEY
-            os.environ.pop("OPENAI_API_KEY", None)
             with pytest.raises(ValidationError):
-                Settings()
+                Settings(_env_file=None)
 
     def test_settings_default_values(self) -> None:
         """Settings should have correct default values."""
-        with patch.dict(os.environ, {"OPENAI_API_KEY": "sk-test"}):
-            settings = Settings()
+        with patch.dict(os.environ, {"OPENAI_API_KEY": "sk-test"}, clear=True):
+            settings = Settings(_env_file=None)
             assert settings.output_format == "txt"
             assert settings.concurrency == 5
             assert settings.language == "auto"
@@ -42,31 +40,35 @@ def test_settings_concurrency_validation_min(self) -> None:
         with patch.dict(
             os.environ,
             {"OPENAI_API_KEY": "sk-test", "TRANSCRIBE_CONCURRENCY": "0"},
+            clear=True,
         ):
             with pytest.raises(ValidationError) as exc_info:
-                Settings()
+                Settings(_env_file=None)
             assert "at least 1" in str(exc_info.value)
 
     def test_settings_concurrency_validation_max(self) -> None:
         """Concurrency should not exceed 20."""
         with patch.dict(
             os.environ,
             {"OPENAI_API_KEY": "sk-test", "TRANSCRIBE_CONCURRENCY": "25"},
+            clear=True,
         ):
             with pytest.raises(ValidationError) as exc_info:
-                Settings()
+                Settings(_env_file=None)
             assert "cannot exceed 20" in str(exc_info.value)
 
     def test_settings_output_dir_resolved(self) -> None:
         """Output directory should be resolved to absolute path."""
-        with patch.dict(os.environ, {"OPENAI_API_KEY": "sk-test"}):
-            settings = Settings(output_dir=Path("."))
+        with patch.dict(os.environ, {"OPENAI_API_KEY": "sk-test"}, clear=True):
+            settings = Settings(_env_file=None, output_dir=Path("."))
             assert settings.output_dir.is_absolute()
 
     def test_settings_api_key_not_in_repr(self) -> None:
         """API key should not appear in string representation (security)."""
-        with patch.dict(os.environ, {"OPENAI_API_KEY": "sk-secret-key-12345"}):
-            settings = Settings()
+        with patch.dict(
+            os.environ, {"OPENAI_API_KEY": "sk-secret-key-12345"}, clear=True
+        ):
+            settings = Settings(_env_file=None)
             repr_str = repr(settings)
             assert "sk-secret-key-12345" not in repr_str
             assert "SecretStr" in repr_str or "**" in repr_str