feat(block-kit): add card block example

block-kit/README.md

@@ -9,6 +9,7 @@ Read the [docs](https://docs.slack.dev/block-kit/) to learn concepts behind thes
 ### Blocks
 
 - **[Actions](https://docs.slack.dev/reference/block-kit/blocks/actions-block)**: Holds multiple interactive elements. [Implementation](./src/blocks/actions.py).
+- **[Card](https://docs.slack.dev/reference/block-kit/blocks/card-block)**: Displays content in a card. [Implementation](./src/blocks/card.py).
 - **[Context](https://docs.slack.dev/reference/block-kit/blocks/context-block)**: Provides contextual info, which can include both images and text. [Implementation](./src/blocks/context.py).
 - **[Context actions](https://docs.slack.dev/reference/block-kit/blocks/context-actions-block)**: Displays actions as contextual info, which can include both feedback buttons and icon buttons. [Implementation](./src/blocks/context_actions.py).
 - **[Divider](https://docs.slack.dev/reference/block-kit/blocks/divider-block)**: Visually separates pieces of info inside of a message. [Implementation](./src/blocks/divider.py).

block-kit/src/blocks/card.py

@@ -0,0 +1,33 @@
+from slack_sdk.models.blocks import CardBlock
+from slack_sdk.models.blocks.basic_components import MarkdownTextObject, PlainTextObject
+from slack_sdk.models.blocks.block_elements import ButtonElement, ImageElement
+
+
+def example01() -> CardBlock:
+    """
+    Displays content in a card.
+    https://docs.slack.dev/reference/block-kit/blocks/card-block/
+
+    A card with an icon, title, subtitle, hero image, body, and an action
+    button.
+    """
+    block = CardBlock(
+        icon=ImageElement(  # type: ignore[arg-type]
+            image_url="https://picsum.photos/36/36",
+            alt_text="Icon",
+        ),
+        title=MarkdownTextObject(text="Lumon Industries"),
+        subtitle=MarkdownTextObject(text="Committed to work-life balance"),
+        hero_image=ImageElement(  # type: ignore[arg-type]
+            image_url="https://picsum.photos/400/300",
+            alt_text="Sample hero image",
+        ),
+        body=MarkdownTextObject(text="Please enjoy each card equally."),
+        actions=[
+            ButtonElement(
+                text=PlainTextObject(text="Action Button", emoji=False),
+                action_id="button_action",
+            )
+        ],
+    )
+    return block

block-kit/tests/blocks/test_card.py

@@ -0,0 +1,36 @@
+import json
+
+from src.blocks import card
+
+
+def test_example01():
+    block = card.example01()
+    actual = block.to_dict()
+    expected = {
+        "type": "card",
+        "icon": {
+            "type": "image",
+            "image_url": "https://picsum.photos/36/36",
+            "alt_text": "Icon",
+        },
+        "title": {"type": "mrkdwn", "text": "Lumon Industries"},
+        "subtitle": {"type": "mrkdwn", "text": "Committed to work-life balance"},
+        "hero_image": {
+            "type": "image",
+            "image_url": "https://picsum.photos/400/300",
+            "alt_text": "Sample hero image",
+        },
+        "body": {"type": "mrkdwn", "text": "Please enjoy each card equally."},
+        "actions": [
+            {
+                "type": "button",
+                "text": {
+                    "type": "plain_text",
+                    "text": "Action Button",
+                    "emoji": False,
+                },
+                "action_id": "button_action",
+            }
+        ],
+    }
+    assert json.dumps(actual, sort_keys=True) == json.dumps(expected, sort_keys=True)