Adding examples

Author: leandrodamascena

aws_lambda_powertools/utilities/data_classes/appsync_resolver_event.py

@@ -184,9 +184,9 @@ def identity(self) -> Union[None, AppSyncIdentityIAM, AppSyncIdentityCognito]:
         return get_identity_object(self.get("identity"))
 
     @property
-    def source(self) -> Optional[Dict[str, Any]]:
+    def source(self) -> Dict[str, Any]:
         """A map that contains the resolution of the parent field."""
-        return self.get("source")
+        return self.get("source") or {}
 
     @property
     def request_headers(self) -> Dict[str, str]:

docs/core/event_handler/appsync.md

@@ -383,6 +383,11 @@ In this mode, you must return results in the same order of your batch items, so
     --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver_payload.json"
   	```
 
+=== "getting_started_with_batch_query.graphql"
+  	```typescript hl_lines="4 16 21 29 41 46"
+    --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_query.graphql"
+  	```
+
 #### Processing items individually
 
 ```mermaid
@@ -453,6 +458,11 @@ In this mode, we will:
     --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver_payload.json"
   	```
 
+=== "getting_started_with_batch_query.graphql"
+  	```typescript hl_lines="4 16 21 29 41 46"
+    --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_query.graphql"
+  	```
+
 ##### Raise on error
 
 ```mermaid
@@ -521,6 +531,11 @@ This is useful when you want to stop processing immediately in the event of an u
     --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_resolver_payload.json"
   	```
 
+=== "getting_started_with_batch_query.graphql"
+  	```typescript hl_lines="4 16 21 29 41 46"
+    --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_query.graphql"
+  	```
+
 #### Async
 
 Choose the asynchronous batch processor when your objective is to leverage concurrency capabilities without the necessity of preserving records in a specific order.
@@ -538,6 +553,11 @@ Choose the asynchronous batch processor when your objective is to leverage concu
     --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_async_resolver_payload.json"
   	```
 
+=== "getting_started_with_batch_query.graphql"
+  	```typescript hl_lines="4 16 21 29 41 46"
+    --8<-- "examples/event_handler_graphql/src/getting_started_with_batch_query.graphql"
+  	```
+
 ## Testing your code
 
 You can test your resolvers by passing a mocked or actual AppSync Lambda event that you're expecting.

examples/event_handler_graphql/src/getting_started_with_batch_async_resolver.py

@@ -1,32 +1,35 @@
-from typing import Any, Dict, List
+from __future__ import annotations
+
+from typing import Any
 
 from aws_lambda_powertools.event_handler import AppSyncResolver
 from aws_lambda_powertools.utilities.data_classes import AppSyncResolverEvent
 from aws_lambda_powertools.utilities.typing import LambdaContext
 
 app = AppSyncResolver()
 
+# mimic DB data for simplicity
 posts_related = {
     "1": {"title": "post1"},
     "2": {"title": "post2"},
     "3": {"title": "post3"},
 }
 
 
-def search_batch_posts(posts: List) -> Dict[str, Any]:
+def search_batch_posts(posts: list) -> dict[str, Any]:
     return {post_id: posts_related.get(post_id) for post_id in posts}
 
 
 @app.async_batch_resolver(type_name="Query", field_name="relatedPosts")
-async def related_posts(event: List[AppSyncResolverEvent]) -> List[Any]:
+async def related_posts(event: list[AppSyncResolverEvent]) -> list[Any]:  # (1)!
     # Extract all post_ids in order
-    post_ids = [record.arguments.get("post_id") for record in event]
+    post_ids: list = [record.source.get("post_id") for record in event]  # (2)!
 
     # Get unique post_ids while preserving order
     unique_post_ids = list(dict.fromkeys(post_ids))
 
     # Fetch posts in a single batch operation
-    fetched_posts: Dict = search_batch_posts(unique_post_ids)
+    fetched_posts = search_batch_posts(unique_post_ids)
 
     # Return results in original order
     return [fetched_posts.get(post_id) for post_id in post_ids]

examples/event_handler_graphql/src/getting_started_with_batch_query.graphql

@@ -0,0 +1,12 @@
+query MyQuery {
+  getPost(post_id: "2") {
+    relatedPosts {
+      post_id
+      author
+      relatedPosts {
+        post_id
+        author
+      }
+    }
+  }
+}

examples/event_handler_graphql/src/getting_started_with_batch_resolver.py

@@ -23,10 +23,10 @@ def search_batch_posts(posts: list) -> dict[str, Any]:
 @app.batch_resolver(type_name="Query", field_name="relatedPosts")
 def related_posts(event: list[AppSyncResolverEvent]) -> list[Any]:  # (1)!
     # Extract all post_ids in order
-    post_ids = [record.arguments.get("post_id") for record in event]  # (2)!
+    post_ids: list = [record.source.get("post_id") for record in event]  # (2)!
 
     # Get unique post_ids while preserving order
-    unique_post_ids: list[str] = list(dict.fromkeys(post_ids))
+    unique_post_ids = list(dict.fromkeys(post_ids))
 
     # Fetch posts in a single batch operation
     fetched_posts = search_batch_posts(unique_post_ids)

examples/event_handler_graphql/src/getting_started_with_batch_resolver_payload.json

@@ -1,52 +1,59 @@
 [
-    {
-       "arguments":{
-          "post_id":"1"
-       },
-       "identity":"None",
-       "source":"None",
-       "request":{
-          "headers":{
-             "x-forwarded-for":"18.68.31.36",
-             "sec-ch-ua-mobile":"?0"
-          }
-       },
-       "prev":"None",
-       "info":{
-          "fieldName":"relatedPosts",
-          "selectionSetList":[
-             "relatedPosts"
-          ],
-          "selectionSetGraphQL":"{\n  relatedPosts {\n    downs\n    content\n    relatedPosts {\n      ups\n      downs\n      relatedPosts {\n        content\n        downs\n      }\n    }\n  }\n}",
-          "parentTypeName":"Query",
-          "variables":{
-
-          }
-       }
-    },
-    {
-        "arguments":{
-           "post_id":"2"
-        },
-        "identity":"None",
-        "source":"None",
-        "request":{
-           "headers":{
-              "x-forwarded-for":"18.68.31.36",
-              "sec-ch-ua-mobile":"?0"
-           }
-        },
-        "prev":"None",
-        "info":{
-           "fieldName":"relatedPosts",
-           "selectionSetList":[
-              "relatedPosts"
-           ],
-           "selectionSetGraphQL":"{\n  relatedPosts {\n    downs\n    content\n    relatedPosts {\n      ups\n      downs\n      relatedPosts {\n        content\n        downs\n      }\n    }\n  }\n}",
-           "parentTypeName":"Query",
-           "variables":{
-
-           }
-        }
-     }
- ]
+   {
+      "arguments":{},
+      "identity":"None",
+      "source":{
+         "post_id":"1",
+         "author":"Author1"
+      },
+      "prev":"None",
+      "info":{
+         "selectionSetList":[
+            "post_id",
+            "author"
+         ],
+         "selectionSetGraphQL":"{\n  post_id\n  author\n}",
+         "fieldName":"relatedPosts",
+         "parentTypeName":"Post",
+         "variables":{}
+      }
+   },
+   {
+      "arguments":{},
+      "identity":"None",
+      "source":{
+         "post_id":"2",
+         "author":"Author2"
+      },
+      "prev":"None",
+      "info":{
+         "selectionSetList":[
+            "post_id",
+            "author"
+         ],
+         "selectionSetGraphQL":"{\n  post_id\n  author\n}",
+         "fieldName":"relatedPosts",
+         "parentTypeName":"Post",
+         "variables":{}
+      }
+   },
+   {
+      "arguments":{},
+      "identity":"None",
+      "source":{
+         "post_id":"1",
+         "author":"Author1"
+      },
+      "prev":"None",
+      "info":{
+         "selectionSetList":[
+            "post_id",
+            "author"
+         ],
+         "selectionSetGraphQL":"{\n  post_id\n  author\n}",
+         "fieldName":"relatedPosts",
+         "parentTypeName":"Post",
+         "variables":{}
+      }
+   }
+]