Support projection build operation

packages/links/package.json

@@ -23,6 +23,7 @@
     "graphql-upload": "11.0.0"
   },
   "dependencies": {
+    "@graphql-tools/utils": "6.0.3",
     "apollo-link": "1.2.14",
     "apollo-upload-client": "13.0.0",
     "form-data": "3.0.0",

packages/utils/src/build-operation-for-field.ts

@@ -51,6 +51,12 @@ export type Skip = string[];
 export type Force = string[];
 export type Ignore = string[];
 
+export type SelectedFields =
+  | {
+      [key: string]: SelectedFields;
+    }
+  | boolean;
+
 export function buildOperationNodeForField({
   schema,
   kind,
@@ -60,6 +66,7 @@ export function buildOperationNodeForField({
   depthLimit,
   circularReferenceDepth,
   argNames,
+  selectedFields = true,
 }: {
   schema: GraphQLSchema;
   kind: OperationTypeNode;
@@ -69,6 +76,7 @@ export function buildOperationNodeForField({
   depthLimit?: number;
   circularReferenceDepth?: number;
   argNames?: string[];
+  selectedFields?: SelectedFields;
 }) {
   resetOperationVariables();
   resetFieldMap();
@@ -82,6 +90,7 @@ export function buildOperationNodeForField({
     depthLimit: depthLimit || Infinity,
     circularReferenceDepth: circularReferenceDepth || 1,
     argNames,
+    selectedFields,
   });
 
   // attach variables
@@ -102,6 +111,7 @@ function buildOperationAndCollectVariables({
   depthLimit,
   circularReferenceDepth,
   argNames,
+  selectedFields,
 }: {
   schema: GraphQLSchema;
   fieldName: string;
@@ -111,6 +121,7 @@ function buildOperationAndCollectVariables({
   depthLimit: number;
   circularReferenceDepth: number;
   argNames?: string[];
+  selectedFields: SelectedFields;
 }): OperationDefinitionNode {
   const typeMap: Record<OperationTypeNode, GraphQLObjectType> = {
     query: schema.getQueryType()!,
@@ -154,6 +165,7 @@ function buildOperationAndCollectVariables({
           schema,
           depth: 0,
           argNames,
+          selectedFields,
         }),
       ],
     },
@@ -173,6 +185,7 @@ function resolveSelectionSet({
   schema,
   depth,
   argNames,
+  selectedFields,
 }: {
   parent: GraphQLNamedType;
   type: GraphQLNamedType;
@@ -185,9 +198,10 @@ function resolveSelectionSet({
   circularReferenceDepth: number;
   schema: GraphQLSchema;
   depth: number;
+  selectedFields: SelectedFields;
   argNames?: string[];
 }): SelectionSetNode | void {
-  if (depth > depthLimit) {
+  if (typeof selectedFields === 'boolean' && depth > depthLimit) {
     return;
   }
   if (isUnionType(type)) {
@@ -224,19 +238,11 @@ function resolveSelectionSet({
               schema,
               depth,
               argNames,
+              selectedFields,
             }) as SelectionSetNode,
           };
         })
-        .filter(f => {
-          if (f) {
-            if ('selectionSet' in f) {
-              return f.selectionSet?.selections?.length;
-            } else {
-              return true;
-            }
-          }
-          return false;
-        }),
+        .filter(fragmentNode => fragmentNode?.selectionSet?.selections?.length > 0),
     };
   }
 
@@ -276,9 +282,11 @@ function resolveSelectionSet({
               schema,
               depth,
               argNames,
+              selectedFields,
             }) as SelectionSetNode,
           };
-        }),
+        })
+        .filter(fragmentNode => fragmentNode?.selectionSet?.selections?.length > 0),
     };
   }
 
@@ -312,19 +320,23 @@ function resolveSelectionSet({
           });
         })
         .map(fieldName => {
-          return resolveField({
-            type: type,
-            field: fields[fieldName],
-            models,
-            path: [...path, fieldName],
-            ancestors,
-            ignore,
-            depthLimit,
-            circularReferenceDepth,
-            schema,
-            depth,
-            argNames,
-          });
+          const selectedSubFields = typeof selectedFields === 'object' ? selectedFields[fieldName] : true;
+          if (selectedSubFields) {
+            return resolveField({
+              type: type,
+              field: fields[fieldName],
+              models,
+              path: [...path, fieldName],
+              ancestors,
+              ignore,
+              depthLimit,
+              circularReferenceDepth,
+              schema,
+              depth,
+              argNames,
+              selectedFields: selectedSubFields,
+            });
+          }
         })
         .filter(f => {
           if (f) {
@@ -398,6 +410,7 @@ function resolveField({
   schema,
   depth,
   argNames,
+  selectedFields,
 }: {
   type: GraphQLObjectType;
   field: GraphQLField<any, any>;
@@ -410,6 +423,7 @@ function resolveField({
   circularReferenceDepth: number;
   schema: GraphQLSchema;
   depth: number;
+  selectedFields: SelectedFields;
   argNames?: string[];
 }): SelectionNode {
   const namedType = getNamedType(field.type);
@@ -480,6 +494,7 @@ function resolveField({
           schema,
           depth: depth + 1,
           argNames,
+          selectedFields,
         }) || undefined,
       arguments: args,
     };

packages/utils/tests/build-operation-node-for-field.spec.ts

@@ -519,3 +519,44 @@ test('arguments', async () => {
     `)
   );
 });
+
+test('selectedFields', async () => {
+
+  const document = buildOperationNodeForField({
+    schema,
+    kind: 'query',
+    field: 'user',
+    selectedFields: {
+      favoriteFood: {
+        dough: true,
+        toppings: true,
+        asian: true,
+      },
+      shelf: true, // Add all nested fields
+    }
+  })!;
+
+  expect(clean(document)).toEqual(
+    clean(/* GraphQL */ `
+      query userQuery($id: ID!) {
+        user(id: $id) {
+          favoriteFood {
+            ... on Pizza {
+              dough
+              toppings
+            }
+            ... on Salad {
+              ... on Coleslaw {
+                asian
+              }
+            }
+          }
+          shelf {
+            id
+            title
+          }
+        }
+      }
+    `)
+  );
+})