fix: merge directives in extensions

.changeset/fair-humans-flow.md

@@ -0,0 +1,6 @@
+---
+'@graphql-tools/schema': patch
+'@graphql-tools/utils': patch
+---
+
+Merge directives in the extensions

packages/schema/tests/__snapshots__/merge-schemas.spec.ts.snap

@@ -0,0 +1,11 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Merge Schemas should merge schemas with directives in extensions 1`] = `
+"schema @onSchema(name: "a") @onSchema(name: "b") {
+  query: Query
+}
+
+type Query @onType(name: "a") @onType(name: "b") {
+  a: String @onField(name: "a") @onField(name: "b")
+}"
+`;

packages/schema/tests/merge-schemas.spec.ts

@@ -1,4 +1,13 @@
-import { buildSchema, graphql, GraphQLScalarType, GraphQLSchema, Kind, print } from 'graphql';
+import {
+  buildSchema,
+  graphql,
+  GraphQLObjectType,
+  GraphQLScalarType,
+  GraphQLSchema,
+  GraphQLString,
+  Kind,
+  print,
+} from 'graphql';
 import { makeExecutableSchema } from '@graphql-tools/schema';
 import { assertSome, printSchemaWithDirectives } from '@graphql-tools/utils';
 import { assertListValueNode } from '../../testing/assertion.js';
@@ -557,4 +566,77 @@ type City {
 }`.trim(),
     );
   });
+  it('should merge schemas with directives in extensions', () => {
+    const aSchema = new GraphQLSchema({
+      extensions: {
+        directives: {
+          onSchema: {
+            name: 'a',
+          },
+        },
+      },
+      query: new GraphQLObjectType({
+        name: 'Query',
+        extensions: {
+          directives: {
+            onType: {
+              name: 'a',
+            },
+          },
+        },
+        fields: {
+          a: {
+            type: GraphQLString,
+            resolve: () => 'a',
+            extensions: {
+              directives: {
+                onField: {
+                  name: 'a',
+                },
+              },
+            },
+          },
+        },
+      }),
+    });
+    const bSchema = new GraphQLSchema({
+      extensions: {
+        directives: {
+          onSchema: {
+            name: 'b',
+          },
+        },
+      },
+      query: new GraphQLObjectType({
+        name: 'Query',
+        extensions: {
+          directives: {
+            onType: {
+              name: 'b',
+            },
+          },
+        },
+        fields: {
+          a: {
+            type: GraphQLString,
+            resolve: () => 'a',
+            extensions: {
+              directives: {
+                onField: {
+                  name: 'b',
+                },
+              },
+            },
+          },
+        },
+      }),
+    });
+    const mergedSchema = mergeSchemas({
+      schemas: [aSchema, bSchema],
+      assumeValid: true,
+      assumeValidSDL: true,
+    });
+    const printedSchema = printSchemaWithDirectives(mergedSchema);
+    expect(printedSchema.trim()).toMatchSnapshot();
+  });
 });

packages/utils/src/extractExtensionsFromSchema.ts

@@ -8,62 +8,98 @@ import {
   SchemaExtensions,
 } from './types.js';
 
+function handleDirectiveExtensions(extensions: any = {}) {
+  const finalExtensions: any = {
+    ...extensions,
+  };
+  const directives = finalExtensions.directives;
+  if (directives != null) {
+    for (const directiveName in directives) {
+      const directiveObj = directives[directiveName];
+      if (!Array.isArray(directiveObj)) {
+        directives[directiveName] = [directiveObj];
+      }
+    }
+  }
+  return finalExtensions;
+}
+
 export function extractExtensionsFromSchema(schema: GraphQLSchema): SchemaExtensions {
   const result: SchemaExtensions = {
-    schemaExtensions: schema.extensions || {},
+    schemaExtensions: handleDirectiveExtensions(schema.extensions),
     types: {},
   };
 
   mapSchema(schema, {
     [MapperKind.OBJECT_TYPE]: type => {
-      result.types[type.name] = { fields: {}, type: 'object', extensions: type.extensions || {} };
+      result.types[type.name] = {
+        fields: {},
+        type: 'object',
+        extensions: handleDirectiveExtensions(type.extensions),
+      };
       return type;
     },
     [MapperKind.INTERFACE_TYPE]: type => {
       result.types[type.name] = {
         fields: {},
         type: 'interface',
-        extensions: type.extensions || {},
+        extensions: handleDirectiveExtensions(type.extensions),
       };
       return type;
     },
     [MapperKind.FIELD]: (field, fieldName, typeName) => {
       (result.types[typeName] as ObjectTypeExtensions).fields[fieldName] = {
         arguments: {},
-        extensions: field.extensions || {},
+        extensions: handleDirectiveExtensions(field.extensions),
       };
       const args = (field as GraphQLFieldConfig<any, any>).args;
       if (args != null) {
         for (const argName in args) {
           (result.types[typeName] as ObjectTypeExtensions).fields[fieldName].arguments[argName] =
-            args[argName].extensions || {};
+            handleDirectiveExtensions(args[argName].extensions);
         }
       }
       return field;
     },
     [MapperKind.ENUM_TYPE]: type => {
-      result.types[type.name] = { values: {}, type: 'enum', extensions: type.extensions || {} };
+      result.types[type.name] = {
+        values: {},
+        type: 'enum',
+        extensions: handleDirectiveExtensions(type.extensions),
+      };
       return type;
     },
     [MapperKind.ENUM_VALUE]: (value, typeName, _schema, valueName) => {
-      (result.types[typeName] as EnumTypeExtensions).values[valueName] = value.extensions || {};
+      (result.types[typeName] as EnumTypeExtensions).values[valueName] = handleDirectiveExtensions(
+        value.extensions,
+      );
       return value;
     },
     [MapperKind.SCALAR_TYPE]: type => {
-      result.types[type.name] = { type: 'scalar', extensions: type.extensions || {} };
+      result.types[type.name] = {
+        type: 'scalar',
+        extensions: handleDirectiveExtensions(type.extensions),
+      };
       return type;
     },
     [MapperKind.UNION_TYPE]: type => {
-      result.types[type.name] = { type: 'union', extensions: type.extensions || {} };
+      result.types[type.name] = {
+        type: 'union',
+        extensions: handleDirectiveExtensions(type.extensions),
+      };
       return type;
     },
     [MapperKind.INPUT_OBJECT_TYPE]: type => {
-      result.types[type.name] = { fields: {}, type: 'input', extensions: type.extensions || {} };
+      result.types[type.name] = {
+        fields: {},
+        type: 'input',
+        extensions: handleDirectiveExtensions(type.extensions),
+      };
       return type;
     },
     [MapperKind.INPUT_OBJECT_FIELD]: (field, fieldName, typeName) => {
       (result.types[typeName] as InputTypeExtensions).fields[fieldName] = {
-        extensions: field.extensions || {},
+        extensions: handleDirectiveExtensions(field.extensions),
       };
       return field;
     },

packages/utils/src/mergeDeep.ts

@@ -37,10 +37,24 @@ export function mergeDeep<S extends any[]>(
           } else {
             output[key] = mergeDeep([output[key], source[key]] as S, respectPrototype);
           }
+        } else if (Array.isArray(output[key])) {
+          if (Array.isArray(source[key])) {
+            output[key].push(...source[key]);
+          } else {
+            output[key].push(source[key]);
+          }
         } else {
           Object.assign(output, { [key]: source[key] });
         }
       }
+    } else if (Array.isArray(target)) {
+      if (Array.isArray(source)) {
+        target.push(...source);
+      } else {
+        target.push(source);
+      }
+    } else if (Array.isArray(source)) {
+      return [target, ...source];
     }
   }
   return output;

packages/utils/tests/mergeDeep.test.ts

@@ -52,4 +52,10 @@ describe('mergeDeep', () => {
     expect(merged.one.b()).toEqual('b');
     expect(merged.a).toBeUndefined();
   });
+
+  it('merges arrays', () => {
+    const x = { a: [1, 2] };
+    const y = { a: [3, 4] };
+    expect(mergeDeep([x, y])).toEqual({ a: [1, 2, 3, 4] });
+  });
 });