posit-dev · juleswg23 · Oct 27, 2025 · Oct 28, 2025 · Oct 28, 2025 · Oct 28, 2025
diff --git a/emailer_lib/egress.py b/emailer_lib/egress.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 import base64
+import os
 
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
@@ -164,24 +165,104 @@ def send_intermediate_email_with_yagmail(i_email: IntermediateEmail):
     raise NotImplementedError
 
 
-def send_intermediate_email_with_mailgun(i_email: IntermediateEmail):
+def send_intermediate_email_with_mailgun(
+    api_key: str,
+    domain: str,
+    sender: str,
+    i_email: IntermediateEmail,
+):
     """
     Send an Intermediate Email object via Mailgun.
 
     Parameters
     ----------
+    api_key
+        Mailgun API key (found in account settings)
+    domain
+        Your verified Mailgun domain (e.g., "mg.yourdomain.com")
+    sender
+        Email address to send from (must be authorized in your domain)
     i_email
         IntermediateEmail object containing the email content and attachments
 
     Returns
     -------
-    None
+    Response
+        Response from Mailgun API
+
+    Raises
+    ------
+    Exception
+        If the Mailgun API returns an error
+
+    Examples
+    --------
+    ```python
+    email = IntermediateEmail(
+        html="<p>Hello world</p>",
+        subject="Test Email",
+        recipients=["[email protected]"],
+    )
+
+    response = send_intermediate_email_with_mailgun(
+        api_key="your-api-key",
+        domain="mg.yourdomain.com",
+        sender="[email protected]",
+        i_email=email
+    )
+    ```
 
     Notes
     -----
-    This function is a placeholder and has not been implemented yet.
+    Requires the `mailgun` package: `pip install mailgun`
     """
-    raise NotImplementedError
+    from mailgun.client import Client
+
+    # Create Mailgun client
+    client = Client(auth=("api", api_key))
+
+    if i_email.recipients is None:
+        raise TypeError(
+            "i_email must have a populated recipients attribute. Currently, i_email.recipients is None."
+        )
+
+    # Prepare the basic email data
+    data = {
+        "from": sender,
+        "to": i_email.recipients,
+        "subject": i_email.subject,
+        "html": i_email.html,
+    }
+
+    # Add text content if available
+    if i_email.text:
+        data["text"] = i_email.text
+
+    # Prepare files for attachments
+    files = []
+
+    # Handle inline images (embedded in HTML with cid:)
+    for image_name, image_base64 in i_email.inline_attachments.items():
+        img_bytes = base64.b64decode(image_base64)
+        # Use 'inline' for images referenced in HTML with cid:
+        files.append(("inline", (image_name, img_bytes)))
+
+    # Handle external attachments
+    for filename in i_email.external_attachments:
+        with open(filename, "rb") as f:
+            file_data = f.read()
+
+        # Extract just the filename (not full path) for the attachment name
+        basename = os.path.basename(filename)
+        files.append(("attachment", (basename, file_data)))
+
+    # Send the message using Mailgun client
+    response = client.messages.create(
+        data=data, files=files if files else None, domain=domain
+    )
+
+    # The response object has a .json() method that returns the actual data
+    return response
 
 
 def send_intermediate_email_with_smtp(
@@ -190,7 +271,7 @@ def send_intermediate_email_with_smtp(
     username: str,
     password: str,
     i_email: IntermediateEmail,
-    security: str = Literal["tls", "ssl", "smtp"]
+    security: str = Literal["tls", "ssl", "smtp"],
 ):
     """
     Send an Intermediate Email object via SMTP.

diff --git a/emailer_lib/tests/__snapshots__/test_structs.ambr b/emailer_lib/tests/__snapshots__/test_structs.ambr
@@ -0,0 +1,51 @@
+# serializer version: 1
+# name: test_preview_email_complex_html
+  '''
+  <!DOCTYPE html>
+  <html lang="en">
+  <head>
+      <meta charset="UTF-8">
+      <title>Test Email</title>
+      <style>
+          body { font-family: Arial, sans-serif; }
+          .header { background-color: #f0f0f0; padding: 20px; }
+          .content { padding: 20px; }
+      </style>
+  </head>
+  <body>
+  <h2 style="padding-left:16px;">Subject: Complex Email Structure</h2>
+      <div class="header">
+          <h1>Welcome!</h1>
+      </div>
+      <div class="content">
+          <p>This is a <strong>complex</strong> email with <em>formatting</em>.</p>
+          <ul>
+              <li>Item 1</li>
+              <li>Item 2</li>
+              <li>Item 3</li>
+          </ul>
+          <img src="data:image;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==" alt="Test Image" />
+      </div>
+  </body>
+  </html>
+  '''
+# ---
+# name: test_preview_email_simple_html
+  '''
+  <html><body>
+  <h2 style="padding-left:16px;">Subject: Simple Test Email</h2><p>Hello World!</p></body></html>
+  '''
+# ---
+# name: test_preview_email_with_inline_attachments
+  '''
+  <html>
+  <body>
+  <h2 style="padding-left:16px;">Subject: Email with Inline Images</h2>
+  <h1>Email with Images</h1>
+  <img src="data:image;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==" alt="Logo" />
+  <p>Some text content</p>
+  <img src="data:image;base64,/9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0aHBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAABAAEDASIAAhEBAxEB/8QAFQABAQAAAAAAAAAAAAAAAAAAAAv/xAAUEAEAAAAAAAAAAAAAAAAAAAAA/8QAFQEBAQAAAAAAAAAAAAAAAAAAAAX/xAAUEQEAAAAAAAAAAAAAAAAAAAAA/9oADAMBAAIRAxEAPwCwAAA=" alt="Banner" />
+  </body>
+  </html>
+  '''
+# ---
diff --git a/emailer_lib/tests/test_egress.py b/emailer_lib/tests/test_egress.py
@@ -145,7 +145,6 @@ def test_send_intermediate_email_with_smtp_unknown_mime_type(monkeypatch):
 
 
 def test_send_intermediate_email_with_smtp_sendmail_args(monkeypatch):
-    """Test that sendmail is called with correct sender, recipients, and message format."""
     email = make_basic_email()
     mock_smtp, mock_smtp_ssl, context = setup_smtp_mocks(monkeypatch)
 
@@ -204,16 +203,86 @@ def test_send_quarto_email_with_gmail(monkeypatch):
     assert i_email.recipients == ["[email protected]"]
 
 
+def test_send_intermediate_email_with_mailgun(monkeypatch):
+    email = make_basic_email()
+    email.external_attachments = ["file.txt"]
+
+    # Mock the response object with .json() method
+    mock_response = MagicMock()
+    mock_response.json.return_value = {
+        "id": "<20251028141836.beb7f6b3fd2be2b7@sandboxedc0eedbb2da49f39cbc02665f66556c.mailgun.org>",
+        "message": "Queued. Thank you."
+    }
+    mock_response.__repr__ = lambda self: "<Response [200]>"
+
+    # Mock the Mailgun Client
+    mock_client_instance = MagicMock()
+    mock_messages = MagicMock()
+    mock_client_instance.messages = mock_messages
+    mock_messages.create = MagicMock(return_value=mock_response)
+
+    mock_client_class = MagicMock(return_value=mock_client_instance)
+
+    with patch("mailgun.client.Client", mock_client_class):
+        with patch("builtins.open", mock_open(read_data=b"file content")):
+            response = send_intermediate_email_with_mailgun(
+                api_key="test-api-key",
+                domain="mg.example.com",
+                sender="[email protected]",
+                i_email=email,
+            )
+
+    # Verify Client was initialized with correct auth
+    mock_client_class.assert_called_once_with(auth=("api", "test-api-key"))
+
+    mock_messages.create.assert_called_once()
+    call_args = mock_messages.create.call_args
+
+    data = call_args.kwargs["data"]
+    assert data["from"] == "[email protected]"
+    assert data["to"] == ["[email protected]"]
+    assert data["subject"] == "Test"
+    assert data["html"] == "<p>Hi</p>"
+    assert data["text"] == "Plain text"
+
+    # Check files were passed
+    files = call_args.kwargs["files"]
+    assert files is not None
+    assert len(files) == 2  # 1 inline, 1 external
+
+    assert call_args.kwargs["domain"] == "mg.example.com"
+
+    assert response == mock_response
+    assert response.json() == {
+        "id": "<20251028141836.beb7f6b3fd2be2b7@sandboxedc0eedbb2da49f39cbc02665f66556c.mailgun.org>",
+        "message": "Queued. Thank you."
+    }
+
+
+def test_send_intermediate_email_with_mailgun_no_recipients():
+    email = IntermediateEmail(
+        html="<p>Hi</p>",
+        subject="Test",
+        recipients=None,
+    )
+
+    with pytest.raises(TypeError, match="i_email must have a populated recipients attribute"):
+        send_intermediate_email_with_mailgun(
+            api_key="test-api-key",
+            domain="mg.example.com",
+            sender="[email protected]",
+            i_email=email,
+        )
+
+
 @pytest.mark.parametrize(
     "send_func",
     [
         send_intermediate_email_with_redmail,
         send_intermediate_email_with_yagmail,
-        send_intermediate_email_with_mailgun,
     ],
 )
 def test_not_implemented_functions(send_func):
-    """Test that unimplemented send functions raise NotImplementedError."""
     email = make_basic_email()
     with pytest.raises(NotImplementedError):
         send_func(email)
diff --git a/emailer_lib/tests/test_structs.py b/emailer_lib/tests/test_structs.py
@@ -95,3 +95,84 @@ def test_not_implemented_methods(method_name):
     method = getattr(email, method_name)
     with pytest.raises(NotImplementedError):
         method()
+
+
+def test_preview_email_simple_html(tmp_path, snapshot):
+    html = "<html><body><p>Hello World!</p></body></html>"
+    email = IntermediateEmail(
+        html=html,
+        subject="Simple Test Email",
+    )
+
+    out_file = tmp_path / "preview.html"
+    email.write_preview_email(str(out_file))
+    content = out_file.read_text(encoding="utf-8")
+
+    assert content == snapshot
+
+
+def test_preview_email_with_inline_attachments(tmp_path, snapshot):
+    html = """<html>
+<body>
+<h1>Email with Images</h1>
+<img src="cid:logo.png" alt="Logo" />
+<p>Some text content</p>
+<img src="cid:banner.jpg" alt="Banner" />
+</body>
+</html>"""
+    email = IntermediateEmail(
+        html=html,
+        subject="Email with Inline Images",
+        inline_attachments={
+            "logo.png": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==",
+            "banner.jpg": "/9j/4AAQSkZJRgABAQEAYABgAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0aHBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAABAAEDASIAAhEBAxEB/8QAFQABAQAAAAAAAAAAAAAAAAAAAAv/xAAUEAEAAAAAAAAAAAAAAAAAAAAA/8QAFQEBAQAAAAAAAAAAAAAAAAAAAAX/xAAUEQEAAAAAAAAAAAAAAAAAAAAA/9oADAMBAAIRAxEAPwCwAAA="
+        },
+    )
+
+    out_file = tmp_path / "preview.html"
+    email.write_preview_email(str(out_file))
+    content = out_file.read_text(encoding="utf-8")
+
+    assert content == snapshot
+
+
+def test_preview_email_complex_html(tmp_path, snapshot):
+    html = """<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Test Email</title>
+    <style>
+        body { font-family: Arial, sans-serif; }
+        .header { background-color: #f0f0f0; padding: 20px; }
+        .content { padding: 20px; }
+    </style>
+</head>
+<body>
+    <div class="header">
+        <h1>Welcome!</h1>
+    </div>
+    <div class="content">
+        <p>This is a <strong>complex</strong> email with <em>formatting</em>.</p>
+        <ul>
+            <li>Item 1</li>
+            <li>Item 2</li>
+            <li>Item 3</li>
+        </ul>
+        <img src="cid:test.png" alt="Test Image" />
+    </div>
+</body>
+</html>"""
+    email = IntermediateEmail(
+        html=html,
+        subject="Complex Email Structure",
+        inline_attachments={
+            "test.png": "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg=="
+        },
+    )
+
+    out_file = tmp_path / "preview.html"
+    email.write_preview_email(str(out_file))
+    content = out_file.read_text(encoding="utf-8")
+
+    assert content == snapshot
diff --git a/pyproject.toml b/pyproject.toml
@@ -30,6 +30,11 @@ dev = [
     "quartodoc",
     "pytest-cov",
     "griffe",
+    "syrupy",
+]
+
+mailgun = [
+    "mailgun"
 ]
 
 docs = [