Update buildScalar.js

Author: migueloller

src/build/__tests__/buildScalar-test.js

@@ -1,9 +1,14 @@
-import { GraphQLScalarType } from 'graphql/type';
+/* @flow */
+
+import { type GraphQLScalarTypeConfig, GraphQLScalarType } from 'graphql/type';
 import { parse } from 'graphql/language';
 import buildScalar from '../buildScalar';
 
 describe('buildScalar()', () => {
-  const generateScalarAST = ({ description, name = 'Scalar' } = {}) => parse(`
+  const generateScalarNode = ({
+    description,
+    name = 'Scalar',
+  }: { description: string, name?: string } = {}): Object => parse(`
     # ${description === undefined ? '' : description}
     scalar ${name}
   `).definitions[0];
@@ -13,30 +18,36 @@ describe('buildScalar()', () => {
     serialize,
     parseValue,
     parseLiteral,
-  } = {}) => new GraphQLScalarType({ name, description, serialize, parseValue, parseLiteral });
+  }: $Shape<GraphQLScalarTypeConfig<*, *>> = {}) => new GraphQLScalarType({
+    name,
+    description,
+    serialize,
+    parseValue,
+    parseLiteral,
+  });
 
-  it('should throw with without `serialize` in config', () => {
-    expect(() => buildScalar(generateScalarAST())).toThrow();
+  test('throws with without `serialize` in config', () => {
+    expect(() => buildScalar(generateScalarNode(), ({}: Object))).toThrow();
   });
 
-  it('should work with `serialize` in config', () => {
+  test('builds with `serialize` in config', () => {
     const config = { serialize() {} };
-    expect(buildScalar(generateScalarAST(), config)).toEqual(generateScalarType(config));
+    expect(buildScalar(generateScalarNode(), config)).toEqual(generateScalarType(config));
   });
 
-  it('should work with `serialize` in config and description in AST', () => {
+  test('builds with `serialize` in config and description in AST', () => {
     const config = { description: 'A description', serialize() {} };
-    expect(buildScalar(generateScalarAST(config), config)).toEqual(generateScalarType(config));
+    expect(buildScalar(generateScalarNode(config), config)).toEqual(generateScalarType(config));
   });
 
-  it('should work with `serialize`, `parseValue`, and `parseLiteral` in config', () => {
+  test('builds with `serialize`, `parseValue`, and `parseLiteral` in config', () => {
     const config = { serialize() {}, parseValue() {}, parseLiteral() {} };
-    expect(buildScalar(generateScalarAST(), config)).toEqual(generateScalarType(config));
+    expect(buildScalar(generateScalarNode(), config)).toEqual(generateScalarType(config));
   });
 
-  it('should work with GraphQL scalar type', () => {
+  test('builds with GraphQLScalarType', () => {
     const config = { serialize() {} };
-    expect(buildScalar(generateScalarAST(), generateScalarType(config)))
+    expect(buildScalar(generateScalarNode(), generateScalarType(config)))
       .toEqual(generateScalarType(config));
   });
 });

src/build/buildScalar.js

@@ -1,15 +1,26 @@
+/* @flow */
+
+import type { ValueNode, ScalarTypeDefinitionNode } from 'graphql/language';
 import { GraphQLScalarType } from 'graphql/type';
-import { getDescription } from 'graphql/utilities/buildASTSchema';
-
-export default function buildScalar(scalarAST, config = {}) {
-  const {
-    serialize,
-    parseValue,
-    parseLiteral,
-    // eslint-disable-next-line no-underscore-dangle
-  } = config instanceof GraphQLScalarType ? config._scalarConfig : config;
-  const scalarTypeConfig = { name: scalarAST.name.value, serialize, parseValue, parseLiteral };
-  const description = getDescription(scalarAST);
-  if (description) scalarTypeConfig.description = description;
-  return new GraphQLScalarType(scalarTypeConfig);
+import getDescription from './getDescription';
+
+type PartialConfig<TInternal, TExternal> = {
+  name?: string,
+  description?: string,
+  serialize: (value: mixed) => ?TExternal,
+  parseValue?: (value: mixed) => ?TInternal,
+  parseLiteral?: (valueNode: ValueNode) => ?TInternal,
+}
+
+type Config = PartialConfig<*, *> | GraphQLScalarType;
+
+export default function buildScalar(node: ScalarTypeDefinitionNode, config: Config) {
+  // eslint-disable-next-line no-underscore-dangle
+  const scalarTypeConfig = config instanceof GraphQLScalarType ? config._scalarConfig : config;
+
+  return new GraphQLScalarType({
+    ...scalarTypeConfig,
+    name: node.name.value,
+    description: getDescription(node),
+  });
 }