feat(graphql-connection-transformer): allow null key-based connections (

#5153) * feat(graphql-connection-transformer): allow null key-based connections Remove non-null check from key-based connections. Add early-return to request mapping templates when a specified key is null. Future work needed to allow pk values to be integers in connections. * fix: add passing test Co-authored-by: Josue Ruiz <josurui@amazon.com>
aws-amplify · Jan 22, 2021 · e9c8276 · e9c8276
1 parent 5789b26
commit e9c8276
Show file tree

Hide file tree

Showing 3 changed files with 314 additions and 31 deletions.
diff --git a/packages/graphql-connection-transformer/src/ModelConnectionTransformer.ts b/packages/graphql-connection-transformer/src/ModelConnectionTransformer.ts
@@ -71,15 +71,14 @@ function validateKeyField(field: FieldDefinitionNode): void {
  * @param field: the field to be checked.
  */
 function validateKeyFieldConnectionWithKey(field: FieldDefinitionNode, ctx: TransformerContext): void {
-  const isNonNull = isNonNullType(field.type);
   const isAList = isListType(field.type);
   const isAScalarOrEnum = isScalarOrEnum(field.type, ctx.getTypeDefinitionsOfKind(Kind.ENUM_TYPE_DEFINITION) as EnumTypeDefinitionNode[]);
 
   // The only valid key fields are single non-null fields.
-  if (!isAList && isNonNull && isAScalarOrEnum) {
+  if (!isAList && isAScalarOrEnum) {
     return;
   }
-  throw new InvalidDirectiveError(`All fields provided to an @connection must be non-null scalar or enum fields.`);
+  throw new InvalidDirectiveError(`All fields provided to an @connection must be scalar or enum fields.`);
 }
 
 /**

diff --git a/packages/graphql-connection-transformer/src/resources.ts b/packages/graphql-connection-transformer/src/resources.ts
@@ -19,6 +19,8 @@ import {
   iff,
   raw,
   Expression,
+  or,
+  list,
 } from 'graphql-mapping-template';
 import {
   ResourceConstants,
@@ -149,7 +151,7 @@ export class ResourceFactory {
         // Use Int minvalue as default
         keyObj.attributes.push([
           sortFieldInfo.primarySortFieldName,
-          ref(`util.dynamodb.toDynamoDBJson($util.defaultIfNull($ctx.source.${sortFieldInfo.sortFieldName}, "${NONE_INT_VALUE}"))`),
+          ref(`util.dynamodb.toDynamoDBJson($util.defaultIfNull($ctx.source.${sortFieldInfo.sortFieldName}, ${NONE_INT_VALUE}))`),
         ]);
       }
     }
@@ -160,9 +162,16 @@ export class ResourceFactory {
       FieldName: field,
       TypeName: type,
       RequestMappingTemplate: print(
-        DynamoDBMappingTemplate.getItem({
-          key: keyObj,
-        }),
+        ifElse(
+          or([
+            raw(`$util.isNull($ctx.source.${connectionAttribute})`),
+            ...(sortFieldInfo ? [raw(`$util.isNull($ctx.source.${connectionAttribute})`)] : []),
+          ]),
+          raw('#return'),
+          DynamoDBMappingTemplate.getItem({
+            key: keyObj,
+          }),
+        ),
       ),
       ResponseMappingTemplate: print(DynamoDBMappingTemplate.dynamoDBResponse(false)),
     }).dependsOn(ResourceConstants.RESOURCES.GraphQLSchemaLogicalID);
@@ -209,21 +218,25 @@ export class ResourceFactory {
       FieldName: field,
       TypeName: type,
       RequestMappingTemplate: print(
-        compoundExpression([
-          ...setup,
-          DynamoDBMappingTemplate.query({
-            query: raw('$util.toJson($query)'),
-            scanIndexForward: ifElse(
-              ref('context.args.sortDirection'),
-              ifElse(equals(ref('context.args.sortDirection'), str('ASC')), bool(true), bool(false)),
-              bool(true),
-            ),
-            filter: ifElse(ref('context.args.filter'), ref('util.transform.toDynamoDBFilterExpression($ctx.args.filter)'), nul()),
-            limit: ref('limit'),
-            nextToken: ifElse(ref('context.args.nextToken'), ref('util.toJson($context.args.nextToken)'), nul()),
-            index: str(`gsi-${connectionName}`),
-          }),
-        ]),
+        ifElse(
+          raw(`$util.isNull($context.source.${idFieldName})`),
+          compoundExpression([set(ref('result'), obj({ items: list([]) })), raw('#return($result)')]),
+          compoundExpression([
+            ...setup,
+            DynamoDBMappingTemplate.query({
+              query: raw('$util.toJson($query)'),
+              scanIndexForward: ifElse(
+                ref('context.args.sortDirection'),
+                ifElse(equals(ref('context.args.sortDirection'), str('ASC')), bool(true), bool(false)),
+                bool(true),
+              ),
+              filter: ifElse(ref('context.args.filter'), ref('util.transform.toDynamoDBFilterExpression($ctx.args.filter)'), nul()),
+              limit: ref('limit'),
+              nextToken: ifElse(ref('context.args.nextToken'), ref('util.toJson($context.args.nextToken)'), nul()),
+              index: str(`gsi-${connectionName}`),
+            }),
+          ]),
+        ),
       ),
       ResponseMappingTemplate: print(
         DynamoDBMappingTemplate.dynamoDBResponse(
@@ -283,11 +296,15 @@ export class ResourceFactory {
       FieldName: field,
       TypeName: type,
       RequestMappingTemplate: print(
-        compoundExpression([
-          DynamoDBMappingTemplate.getItem({
-            key: keyObj,
-          }),
-        ]),
+        ifElse(
+          or(connectionAttributes.map(ca => raw(`$util.isNull($ctx.source.${ca})`))),
+          raw('#return'),
+          compoundExpression([
+            DynamoDBMappingTemplate.getItem({
+              key: keyObj,
+            }),
+          ]),
+        ),
       ),
       ResponseMappingTemplate: print(DynamoDBMappingTemplate.dynamoDBResponse(false)),
     }).dependsOn(ResourceConstants.RESOURCES.GraphQLSchemaLogicalID);
@@ -361,7 +378,13 @@ export class ResourceFactory {
       DataSourceName: Fn.GetAtt(ModelResourceIDs.ModelTableDataSourceID(relatedType.name.value), 'Name'),
       FieldName: field,
       TypeName: type,
-      RequestMappingTemplate: print(compoundExpression([...setup, queryObj])),
+      RequestMappingTemplate: print(
+        ifElse(
+          raw(`$util.isNull($ctx.source.${connectionAttributes[0]})`),
+          compoundExpression([set(ref('result'), obj({ items: list([]) })), raw('#return($result)')]),
+          compoundExpression([...setup, queryObj]),
+        ),
+      ),
       ResponseMappingTemplate: print(
         DynamoDBMappingTemplate.dynamoDBResponse(
           false,