Add tests for GraphQLDirective (#1662)

src/type/__tests__/directive-test.js

@@ -0,0 +1,103 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ */
+
+import { describe, it } from 'mocha';
+import { expect } from 'chai';
+
+import { GraphQLDirective, GraphQLString, GraphQLInt } from '../';
+
+describe('Type System: Directive', () => {
+  it('defines a directive with no args', () => {
+    const directive = new GraphQLDirective({
+      name: 'Foo',
+      locations: ['QUERY'],
+    });
+
+    expect(directive).to.deep.include({
+      name: 'Foo',
+      args: [],
+      locations: ['QUERY'],
+    });
+  });
+
+  it('defines a directive with multiple args', () => {
+    const directive = new GraphQLDirective({
+      name: 'Foo',
+      args: {
+        foo: { type: GraphQLString },
+        bar: { type: GraphQLInt },
+      },
+      locations: ['QUERY'],
+    });
+
+    expect(directive).to.deep.include({
+      name: 'Foo',
+      args: [
+        {
+          name: 'foo',
+          type: GraphQLString,
+          description: null,
+          defaultValue: undefined,
+          astNode: undefined,
+        },
+        {
+          name: 'bar',
+          type: GraphQLInt,
+          description: null,
+          defaultValue: undefined,
+          astNode: undefined,
+        },
+      ],
+      locations: ['QUERY'],
+    });
+  });
+
+  it('can be stringified and JSON.stringified', () => {
+    const directive = new GraphQLDirective({
+      name: 'Foo',
+      locations: ['QUERY'],
+    });
+
+    expect(String(directive)).to.equal('@Foo');
+    expect(JSON.stringify(directive)).to.equal('"@Foo"');
+  });
+
+  it('reject an unnamed directive', () => {
+    // $DisableFlowOnNegativeTest
+    expect(() => new GraphQLDirective({ locations: ['Query'] })).to.throw(
+      'Directive must be named.',
+    );
+  });
+
+  it('reject directive incorrectly typed args', () => {
+    expect(
+      () =>
+        // $DisableFlowOnNegativeTest
+        new GraphQLDirective({
+          name: 'Foo',
+          locations: ['Query'],
+          args: [],
+        }),
+    ).to.throw('@Foo args must be an object with argument names as keys.');
+  });
+
+  it('reject an directive with undefined locations', () => {
+    // $DisableFlowOnNegativeTest
+    expect(() => new GraphQLDirective({ name: 'Foo' })).to.throw(
+      '@Foo locations must be an Array.',
+    );
+  });
+
+  it('reject an directive with incorrectly typed locations', () => {
+    // $DisableFlowOnNegativeTest
+    expect(() => new GraphQLDirective({ name: 'Foo', locations: {} })).to.throw(
+      '@Foo locations must be an Array.',
+    );
+  });
+});

src/type/directives.js

@@ -63,12 +63,12 @@ export class GraphQLDirective {
     invariant(config.name, 'Directive must be named.');
     invariant(
       Array.isArray(config.locations),
-      'Must provide locations for directive.',
+      `@${config.name} locations must be an Array.`,
     );
 
     const args = config.args || {};
     invariant(
-      !Array.isArray(args),
+      typeof args === 'object' && !Array.isArray(args),
       `@${config.name} args must be an object with argument names as keys.`,
     );