fix(ai-constructs): invalid graphql generation for query tools (#1988)

* add defensive check for empty tool properties

* fix invalid selection set for gql tools with scalar response types

* add changeset

Author: atierian

.changeset/fuzzy-poems-walk.md

@@ -0,0 +1,5 @@
+---
+'@aws-amplify/ai-constructs': patch
+---
+
+fix invalid graphql in tool query generation

packages/ai-constructs/src/conversation/runtime/event-tools-provider/graphql_query_factory.test.ts

@@ -37,9 +37,7 @@ const testCases: Array<TestCase> = [
     },
     expectedQuery: `
     query ToolQuery($property1: String!, $property2: Int) {
-      testQueryName1(property1: $property1, property2: $property2) {
-        testSelection1 testSelection2
-      }
+      testQueryName1(property1: $property1, property2: $property2) { testSelection1 testSelection2 }
     }
     `,
   },
@@ -58,9 +56,30 @@ const testCases: Array<TestCase> = [
     },
     expectedQuery: `
     query ToolQuery {
-      testQueryName2 {
-        testSelection3 testSelection4
-      }
+      testQueryName2 { testSelection3 testSelection4 }
+    }
+    `,
+  },
+  {
+    toolDefinition: {
+      name: 'toolName3',
+      description: 'toolDescription3',
+      inputSchema: {
+        json: {
+          type: 'object',
+          properties: {},
+          required: [],
+        },
+      },
+      graphqlRequestInputDescriptor: {
+        queryName: 'testQueryName3',
+        selectionSet: '',
+        propertyTypes: {},
+      },
+    },
+    expectedQuery: `
+    query ToolQuery {
+      testQueryName3
     }
     `,
   },

packages/ai-constructs/src/conversation/runtime/event-tools-provider/graphql_query_factory.ts

@@ -15,12 +15,11 @@ export class GraphQlQueryFactory {
     const { graphqlRequestInputDescriptor } = toolDefinition;
     const { selectionSet, queryName } = graphqlRequestInputDescriptor;
     const [topLevelQueryArgs, queryArgs] = this.createQueryArgs(toolDefinition);
-
+    const fieldSelection =
+      selectionSet.length > 0 ? ` { ${selectionSet} }` : '';
     const query = `
     query ToolQuery${topLevelQueryArgs} {
-      ${queryName}${queryArgs} {
-        ${selectionSet}
-      }
+      ${queryName}${queryArgs}${fieldSelection}
     }
   `;
 
@@ -36,7 +35,20 @@ export class GraphQlQueryFactory {
     }
 
     const { properties } = inputSchema.json as InputSchemaJson;
-    if (!properties) {
+
+    // The conversation resolver should not pass an empty object as input,
+    // but we're defensively checking for it here anyway because if `properties: {}`
+    // is passed, it will generate invalid GraphQL. e.g.
+    // Valid:
+    // query ToolQuery {
+    //   exampleQuery
+    // }
+    //
+    // Invalid:
+    // query ToolQuery {
+    //   exampleQuery()
+    // }
+    if (!properties || Object.keys(properties).length === 0) {
       return ['', ''];
     }
     const { propertyTypes } = toolDefinition.graphqlRequestInputDescriptor;