@0x/contracts-exchange: Add tests and run prettier.

contracts/test-utils/test/subtests/mocha_blockchain_1.ts

@@ -0,0 +1,10 @@
+import { blockchainTests, BlockchainTestsEnvironment, expect } from '../../src';
+
+// tslint:disable: no-default-export completed-docs
+export function define(env: BlockchainTestsEnvironment): void {
+    blockchainTests('imported subtests', subtestsEnv => {
+        it('shares the same environment object', () => {
+            expect(subtestsEnv).to.eq(env);
+        });
+    });
+}