Add check_credentials method to PostmarkEmailSender

README.md

@@ -125,7 +125,7 @@ The test suite uses [Postmark](https://postmarkapp.com/) to send real test email
 
 ```bash
 # .env
-POSTMARK_API_KEY=your_postmark_api_key_here
+POSTMARK_API_TOKEN=your_postmark_api_token_here
 SENDER_EMAIL=your_email_address_here  # The verified sender email in Postmark
 ```
 
@@ -138,6 +138,28 @@ pytest
 ruff check .
 ```
 
+### Checking Postmark Credentials
+
+The test suite includes a utility to verify that your Postmark credentials are properly configured:
+
+```python
+from tests.email_sender import PostmarkEmailSender
+
+# Initialize sender and check credentials
+sender = PostmarkEmailSender()
+
+# Check if credentials are set (without testing connection)
+result = sender.check_credentials(test_connection=False)
+print(f"Credentials set: {result['credentials_set']}")
+
+# Check if credentials are set and test the connection
+result = sender.check_credentials(test_connection=True)
+if result['connection_valid']:
+    print("Credentials are valid and connection successful!")
+else:
+    print(f"Connection failed: {result['error']}")
+```
+
 ## Credits
 
 - Tacomail Service: [https://tacomail.de/](https://tacomail.de/)

tests/email_sender.py

@@ -20,6 +20,48 @@ def __init__(self):
             raise ValueError("SENDER_EMAIL not found in environment variables")
         self.sender_email = sender_email
 
+    def check_credentials(self, test_connection: bool = True) -> dict:
+        """Check if Postmark credentials are set and optionally test if they're usable.
+
+        Args:
+            test_connection: If True, attempts to connect to SMTP server to validate credentials.
+                           If False, only checks if credentials are present.
+
+        Returns:
+            A dictionary with the following keys:
+                - credentials_set (bool): Whether both API token and sender email are present
+                - api_token_set (bool): Whether POSTMARK_API_TOKEN is set
+                - sender_email_set (bool): Whether SENDER_EMAIL is set
+                - connection_valid (bool or None): Whether connection to SMTP server succeeded.
+                                                   None if test_connection is False.
+                                                   False if credentials are missing and test_connection is True.
+                - error (str or None): Error message if connection test failed
+        """
+        result = {
+            "api_token_set": self.api_token is not None and self.api_token != "",
+            "sender_email_set": self.sender_email is not None and self.sender_email != "",
+            "connection_valid": None,
+            "error": None
+        }
+        result["credentials_set"] = result["api_token_set"] and result["sender_email_set"]
+
+        if test_connection:
+            if not result["credentials_set"]:
+                result["connection_valid"] = False
+                result["error"] = "Missing credentials"
+            else:
+                try:
+                    with smtplib.SMTP(self.SMTP_SERVER, self.SMTP_PORT, timeout=10) as server:
+                        server.starttls()
+                        # Using API token as both username and password (Postmark SMTP authentication)
+                        server.login(self.api_token, self.api_token)
+                        result["connection_valid"] = True
+                except Exception as e:
+                    result["connection_valid"] = False
+                    result["error"] = str(e)
+
+        return result
+
     def send_email(self, to_email: str, subject: str, body: str):
         """Send an email using Postmark SMTP server."""
         msg = MIMEMultipart()

tests/test_tacomail.py

@@ -73,6 +73,51 @@ def test_email_sender_initialization():
     assert sender.SMTP_PORT == 587
 
 
+def test_check_credentials_without_connection_test():
+    """Test that check_credentials returns proper status without testing connection."""
+    sender = PostmarkEmailSender()
+    result = sender.check_credentials(test_connection=False)
+
+    # Should have all required keys
+    assert "credentials_set" in result
+    assert "api_token_set" in result
+    assert "sender_email_set" in result
+    assert "connection_valid" in result
+    assert "error" in result
+
+    # Credentials should be set (since PostmarkEmailSender.__init__ would have raised if not)
+    assert result["credentials_set"] is True
+    assert result["api_token_set"] is True
+    assert result["sender_email_set"] is True
+
+    # Connection should not be tested
+    assert result["connection_valid"] is None
+    assert result["error"] is None
+
+
+@pytest.mark.flow
+def test_check_credentials_with_connection_test():
+    """Test that check_credentials validates connection to Postmark SMTP server."""
+    sender = PostmarkEmailSender()
+    result = sender.check_credentials(test_connection=True)
+
+    # Should have all required keys
+    assert "credentials_set" in result
+    assert "api_token_set" in result
+    assert "sender_email_set" in result
+    assert "connection_valid" in result
+    assert "error" in result
+
+    # Credentials should be set
+    assert result["credentials_set"] is True
+    assert result["api_token_set"] is True
+    assert result["sender_email_set"] is True
+
+    # Connection should be tested and valid
+    assert result["connection_valid"] is True
+    assert result["error"] is None
+
+
 @pytest.mark.flow
 def test_full_email_flow(client: TacomailClient):
     # Get random email address