fix(default-value): properly build schema default values

CHANGELOG.md

@@ -8,6 +8,7 @@
 - allow defining directives for interface types and theirs fields, with inheritance for object types fields (#744)
 ### Fixes
 - allow defining extension on field resolver level for fields also defined as a property of the class (#776)
+- fix throwing error when schema with dynamic default value was built again (#787)
 ### Others
 - **Breaking Change**: update `graphql-js` peer dependency to `^15.4.0`
 

src/schema/schema-generator.ts

@@ -168,13 +168,15 @@ export abstract class SchemaGenerator {
       defaultValueFromInitializer !== undefined &&
       typeOptions.defaultValue !== defaultValueFromInitializer
     ) {
+      // console.log("ConflictingDefaultValuesError", { typeOptions, defaultValueFromInitializer });
       throw new ConflictingDefaultValuesError(
         typeName,
         fieldName,
         typeOptions.defaultValue,
         defaultValueFromInitializer,
       );
     }
+    // console.log("normal", { typeOptions, defaultValueFromInitializer });
     return typeOptions.defaultValue !== undefined
       ? typeOptions.defaultValue
       : defaultValueFromInitializer;
@@ -506,23 +508,21 @@ export abstract class SchemaGenerator {
           fields: () => {
             let fields = inputType.fields!.reduce<GraphQLInputFieldConfigMap>(
               (fieldsMap, field) => {
-                field.typeOptions.defaultValue = this.getDefaultValue(
+                const defaultValue = this.getDefaultValue(
                   inputInstance,
                   field.typeOptions,
                   field.name,
                   inputType.name,
                 );
 
-                const type = this.getGraphQLInputType(
-                  field.target,
-                  field.name,
-                  field.getType(),
-                  field.typeOptions,
-                );
+                const type = this.getGraphQLInputType(field.target, field.name, field.getType(), {
+                  ...field.typeOptions,
+                  defaultValue,
+                });
                 fieldsMap[field.schemaName] = {
                   description: field.description,
                   type,
-                  defaultValue: field.typeOptions.defaultValue,
+                  defaultValue,
                   astNode: getInputValueDefinitionNode(field.name, type, field.directives),
                   extensions: field.extensions,
                 };
@@ -749,21 +749,19 @@ export abstract class SchemaGenerator {
   ) {
     const argumentInstance = new (argumentType.target as any)();
     argumentType.fields!.forEach(field => {
-      field.typeOptions.defaultValue = this.getDefaultValue(
+      const defaultValue = this.getDefaultValue(
         argumentInstance,
         field.typeOptions,
         field.name,
         argumentType.name,
       );
       args[field.schemaName] = {
         description: field.description,
-        type: this.getGraphQLInputType(
-          field.target,
-          field.name,
-          field.getType(),
-          field.typeOptions,
-        ),
-        defaultValue: field.typeOptions.defaultValue,
+        type: this.getGraphQLInputType(field.target, field.name, field.getType(), {
+          ...field.typeOptions,
+          defaultValue,
+        }),
+        defaultValue,
       };
     });
   }

tests/functional/default-values.ts

@@ -0,0 +1,49 @@
+import "reflect-metadata";
+import { IntrospectionSchema } from "graphql";
+import {
+  Arg,
+  buildSchema,
+  ClassType,
+  Field,
+  getMetadataStorage,
+  InputType,
+  Query,
+  Resolver,
+} from "../../src";
+
+import { getSchemaInfo } from "../helpers/getSchemaInfo";
+
+describe("default values", () => {
+  describe("dynamic default value", () => {
+    let schemaIntrospection: IntrospectionSchema;
+    let sampleResolver: ClassType;
+    beforeAll(async () => {
+      getMetadataStorage().clear();
+
+      @InputType()
+      class SampleInput {
+        @Field()
+        sampleField: Date = new Date();
+      }
+
+      @Resolver()
+      class SampleResolver {
+        @Query()
+        sampleQuery(@Arg("input") input: SampleInput): string {
+          return "sampleQuery";
+        }
+      }
+      sampleResolver = SampleResolver;
+
+      // get builded schema info from retrospection
+      const schemaInfo = await getSchemaInfo({
+        resolvers: [SampleResolver],
+      });
+      schemaIntrospection = schemaInfo.schemaIntrospection;
+    });
+
+    it("should not throw error when schema with dynamic default has been built again", async () => {
+      await expect(buildSchema({ resolvers: [sampleResolver] })).resolves.not.toThrowError();
+    });
+  });
+});