test(settings): makes settings lazily loaded and then uses monkeypatch to "override" settings

Author: Karl Wooster

src/ynamazon/amazon/models.py

@@ -10,7 +10,7 @@
 from pydantic import BaseModel, ConfigDict, Field, HttpUrl, model_validator
 
 from ynamazon.amazon_transactions import AmazonConfig
-from ynamazon.settings import settings
+from ynamazon.settings import get_settings
 from ynamazon.types_pydantic import AmazonSellerType
 from ynamazon.utilities import MISSING, Missing, getattr_path
 from ynamazon.utilities.bases import SimpleDict
@@ -35,7 +35,7 @@ class Item(Entity):
     quantity: Union[int, None] = None
 
     def __str__(self) -> str:
-        if settings.ynab_use_markdown:
+        if get_settings().ynab_use_markdown:
             return f"[{self.title}]({self.link})"
         return self.title
 

src/ynamazon/amazon_transactions.py

@@ -22,7 +22,7 @@
 from rich import print as rprint
 from rich.table import Table
 
-from .settings import settings
+from .settings import get_settings
 from .types_pydantic import AmazonItemType
 
 
@@ -73,8 +73,8 @@ class AmazonConfig(BaseModel):
 
     model_config = ConfigDict(arbitrary_types_allowed=True)
 
-    username: EmailStr = Field(default_factory=lambda: settings.amazon_user)
-    password: SecretStr = Field(default_factory=lambda: settings.amazon_password)
+    username: EmailStr = Field(default_factory=lambda: get_settings().amazon_user)
+    password: SecretStr = Field(default_factory=lambda: get_settings().amazon_password)
     config: AmazonOrdersConfig = Field(default_factory=lambda: AmazonOrdersConfig())
     debug: bool = False
 

src/ynamazon/cli/cli.py

@@ -16,7 +16,7 @@
 from ynamazon.amazon_transactions import AmazonConfig, get_amazon_transactions
 from ynamazon.exceptions import YnabSetupError
 from ynamazon.main import process_transactions
-from ynamazon.settings import ConfigFile, SecretApiKey, SecretBudgetId, settings
+from ynamazon.settings import ConfigFile, SecretApiKey, SecretBudgetId, get_settings
 from ynamazon.ynab_transactions import (
     TempYnabTransaction,
     get_ynab_transactions,
@@ -35,14 +35,14 @@ def print_ynab_transactions(
         str | None,
         Argument(
             help="YNAB API key",
-            default_factory=lambda: settings.ynab_api_key.get_secret_value(),
+            default_factory=lambda: get_settings().ynab_api_key.get_secret_value(),
         ),
     ],
     budget_id: Annotated[
         str | None,
         Argument(
             help="YNAB Budget ID",
-            default_factory=lambda: settings.ynab_budget_id.get_secret_value(),
+            default_factory=lambda: get_settings().ynab_budget_id.get_secret_value(),
         ),
     ],
 ) -> None:
@@ -83,13 +83,15 @@ def print_ynab_transactions(
 def print_amazon_transactions(
     user_email: Annotated[
         str,
-        Argument(help="Amazon username", default_factory=lambda: settings.amazon_user),
+        Argument(
+            help="Amazon username", default_factory=lambda: get_settings().amazon_user
+        ),
     ],
     user_password: Annotated[
         str,
         Argument(
             help="Amazon password",
-            default_factory=lambda: settings.amazon_password.get_secret_value(),
+            default_factory=lambda: get_settings().amazon_password.get_secret_value(),
         ),
     ],
     order_years: Annotated[
@@ -148,28 +150,28 @@ def ynamazon(
         str | None,
         Argument(
             help="YNAB API key",
-            default_factory=lambda: settings.ynab_api_key.get_secret_value(),
+            default_factory=lambda: get_settings().ynab_api_key.get_secret_value(),
         ),
     ],
     ynab_budget_id: Annotated[
         str | None,
         Argument(
             help="YNAB Budget ID",
-            default_factory=lambda: settings.ynab_budget_id.get_secret_value(),
+            default_factory=lambda: get_settings().ynab_budget_id.get_secret_value(),
         ),
     ],
     amazon_user: Annotated[
         str,
         Argument(
             help="Amazon username",
-            default_factory=lambda: settings.amazon_user,
+            default_factory=lambda: get_settings().amazon_user,
         ),
     ],
     amazon_password: Annotated[
         str,
         Argument(
             help="Amazon password",
-            default_factory=lambda: settings.amazon_password.get_secret_value(),
+            default_factory=lambda: get_settings().amazon_password.get_secret_value(),
         ),
     ],
 ) -> None:
@@ -210,13 +212,13 @@ def new_ynamazon(  # noqa: C901
             config.amazon_user = amazon_user
         if amazon_password is not None:
             config.amazon_password = SecretStr(amazon_password)
-        cli_settings = settings.model_copy(update=config.model_dump())
+        cli_settings = get_settings().model_copy(update=config.model_dump())
     else:
         assert ynab_api_key is not None, "YNAB API key is required"
         assert ynab_budget_id is not None, "YNAB Budget ID is required"
         assert amazon_user is not None, "Amazon username is required"
         assert amazon_password is not None, "Amazon password is required"
-        cli_settings = settings.model_copy(
+        cli_settings = get_settings().model_copy(
             update={
                 "ynab_api_key": SecretApiKey(ynab_api_key),
                 "ynab_budget_id": SecretBudgetId(ynab_budget_id),
@@ -235,7 +237,7 @@ def new_ynamazon(  # noqa: C901
             budget_id=cli_settings.ynab_budget_id.get_secret_value(),
         )
     except YnabSetupError as e:
-        console.print(f"[bold red]Settings error: {e}[/]")
+        console.print(f"[bold red]get_settings() error: {e}[/]")
         console.print(
             "[bold red]Please check your .env file or use the --config option to specify a config file.[/]"
         )
@@ -248,7 +250,7 @@ def new_ynamazon(  # noqa: C901
             debug=debug,
         )
     except ValidationError as e:
-        console.print(f"[bold red]Settings error: {e}[/]")
+        console.print(f"[bold red]get_settings() error: {e}[/]")
         console.print(
             "[bold red]Please check your .env file or use the --config option to specify a config file.[/]"
         )

src/ynamazon/main.py

@@ -14,7 +14,7 @@
 from ynamazon.ynab_memo import process_memo
 
 from .exceptions import YnabSetupError
-from .settings import settings
+from .settings import get_settings
 from .ynab_transactions import default_configuration as ynab_configuration
 from .ynab_transactions import (
     get_ynab_transactions,
@@ -114,7 +114,7 @@ def process_transactions(
     """Match YNAB transactions to Amazon Transactions and optionally update YNAB Memos."""
     amazon_config = amazon_config or AmazonConfig()
     ynab_config = ynab_config or ynab_configuration
-    budget_id = budget_id or settings.ynab_budget_id.get_secret_value()
+    budget_id = budget_id or get_settings().ynab_budget_id.get_secret_value()
 
     console = Console()
 

src/ynamazon/settings.py

@@ -1,3 +1,4 @@
+from functools import lru_cache
 from os import PathLike
 from pathlib import Path
 from typing import Union
@@ -63,8 +64,20 @@ def validate_settings(self) -> "Settings":
             )
         return self
 
+    def get_secret_value(self, key: str) -> Union[str, None]:
+        """Get secret API key or budget ID."""
+        value = getattr(self, key)
+        if value is None:
+            return None
+        if not isinstance(value, SecretStr):
+            raise ValueError(f"{key} is not a SecretStr")
+        return value.get_secret_value()
 
-settings = Settings()  # type: ignore[call-arg]
+
+@lru_cache
+def get_settings() -> Settings:
+    """Get settings from environment variables."""
+    return Settings()  # type: ignore[call-arg]
 
 
 class ConfigFile(BaseModel):

src/ynamazon/ynab_memo.py

@@ -11,7 +11,7 @@
     AMAZON_SUMMARY_PLAIN_PROMPT,
     AMAZON_SUMMARY_SYSTEM_PROMPT,
 )
-from ynamazon.settings import settings
+from ynamazon.settings import get_settings
 
 from .exceptions import (
     InvalidOpenAIAPIKey,
@@ -49,14 +49,11 @@ def generate_ai_summary(
         Exception: For other OpenAI API errors
     """
     # Check if OpenAI key is available
-    if (
-        settings.openai_api_key is None
-        or not settings.openai_api_key.get_secret_value()
-    ):
+    if get_settings().openai_api_key is None:
         raise MissingOpenAIAPIKey("OpenAI API key not found")
 
     # Create client
-    client = OpenAI(api_key=settings.openai_api_key.get_secret_value())
+    client = OpenAI(api_key=get_settings().get_secret_value("openai_api_key"))
 
     # Prepare content for summarization
     partial_order_note = ""
@@ -69,7 +66,7 @@ def generate_ai_summary(
     # Select the appropriate prompt based on markdown setting
     user_prompt = (
         AMAZON_SUMMARY_MARKDOWN_PROMPT
-        if settings.ynab_use_markdown
+        if get_settings().ynab_use_markdown
         else AMAZON_SUMMARY_PLAIN_PROMPT
     )
 
@@ -308,12 +305,12 @@ def summarize_memo_with_ai(memo: str, order_url: str) -> str:
 def process_memo(memo: str) -> str:
     """Process a memo using AI summarization if enabled, otherwise use truncation if needed.
 
-    This function handles both markdown and non-markdown memos based on the settings.ynab_use_markdown setting:
+    This function handles both markdown and non-markdown memos based on the get_settings().ynab_use_markdown setting:
     - If markdown is enabled, it preserves markdown formatting in the output
     - If markdown is disabled, it strips all markdown formatting
 
     The processing strategy is:
-    1. If AI summarization is enabled (settings.use_ai_summarization):
+    1. If AI summarization is enabled (get_settings().use_ai_summarization):
        - Uses OpenAI to generate a concise summary
        - Preserves markdown formatting if enabled
        - Ensures the summary fits within YNAB's character limit
@@ -335,7 +332,7 @@ def process_memo(memo: str) -> str:
         logger.warning("No Amazon order URL found in memo")
         return original_memo
 
-    if settings.use_ai_summarization:
+    if get_settings().use_ai_summarization:
         logger.info("Using AI summarization")
         processed_memo = summarize_memo_with_ai(original_memo, order_url)
         if processed_memo:
@@ -367,7 +364,7 @@ def summarize_memo(memo: str) -> str:
         logger.warning("No Amazon order URL found in memo")
         return truncate_memo(original_memo)
 
-    if settings.use_ai_summarization:
+    if get_settings().use_ai_summarization:
         processed_memo = summarize_memo_with_ai(original_memo, order_url)
         if processed_memo:
             return processed_memo

src/ynamazon/ynab_transactions.py

@@ -18,12 +18,12 @@
 
 from ynamazon.amazon.models import Transaction
 from ynamazon.exceptions import YnabSetupError
-from ynamazon.settings import settings
+from ynamazon.settings import get_settings
 
 default_configuration = Configuration(
-    access_token=settings.ynab_api_key.get_secret_value()
+    access_token=get_settings().ynab_api_key.get_secret_value()
 )
-my_budget_id = settings.ynab_budget_id
+my_budget_id = get_settings().ynab_budget_id
 
 PARTIAL_ORDER_MEMO = "-This transaction doesn't represent the entire order. The order total is ${order_total:.2f}-"
 YNAB_MAX_MEMO_LENGTH = 500
@@ -236,20 +236,20 @@ def get_ynab_transactions(
     amazon_needs_memo_payee = find_item_by_attribute(
         items=payees,
         attribute="name",
-        value=settings.ynab_payee_name_to_be_processed,
+        value=get_settings().ynab_payee_name_to_be_processed,
     )
     amazon_with_memo_payee = find_item_by_attribute(
         items=payees,
         attribute="name",
-        value=settings.ynab_payee_name_processing_completed,
+        value=get_settings().ynab_payee_name_processing_completed,
     )
     if amazon_needs_memo_payee is None:
         raise YnabSetupError(
-            f"Payee '{settings.ynab_payee_name_to_be_processed}' not found in YNAB."
+            f"Payee '{get_settings().ynab_payee_name_to_be_processed}' not found in YNAB."
         )
     if amazon_with_memo_payee is None:
         raise YnabSetupError(
-            f"Payee '{settings.ynab_payee_name_processing_completed}' not found in YNAB."
+            f"Payee '{get_settings().ynab_payee_name_processing_completed}' not found in YNAB."
         )
 
     ynab_transactions = get_transactions_by_payee(
@@ -376,7 +376,7 @@ def markdown_formatted_title(title: str, url: Union[str, AnyUrl]) -> str:
     Returns:
         str: A URL string suitable for injection into the memo
     """
-    if settings.ynab_use_markdown:
+    if get_settings().ynab_use_markdown:
         return f"[{title}]({url})"
 
     return title
@@ -392,7 +392,7 @@ def markdown_formatted_link(title: str, url: Union[str, AnyUrl]) -> str:
     Returns:
         str: A URL string suitable for injection into the memo
     """
-    if settings.ynab_use_markdown:
+    if get_settings().ynab_use_markdown:
         return f"[{title}]({url})"
 
     if isinstance(url, AnyUrl):