@0x/contracts-test-utils: Create blockchainTests mocha fixture directive.

`@0x/contracts-test-utils`: Automatically call `chaiSetup.configure()`.
`@0x/contracts-test-utils`: Export `expect` as an alias for `chai.expect`.

contracts/test-utils/package.json

@@ -34,7 +34,6 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/test-utils/README.md",
     "devDependencies": {
-        "mocha": "^4.1.0",
         "npm-run-all": "^4.1.2",
         "shx": "^0.2.2",
         "tslint": "5.11.0",
@@ -67,7 +66,8 @@
         "ethers": "~4.0.4",
         "js-combinatorics": "^0.5.3",
         "lodash": "^4.17.11",
-        "make-promises-safe": "^1.1.0"
+        "make-promises-safe": "^1.1.0",
+        "mocha": "^4.1.0"
     },
     "publishConfig": {
         "access": "public"

contracts/test-utils/src/chai_setup.ts

@@ -1 +1,7 @@
+import { chaiSetup } from '@0x/dev-utils';
 export { chaiSetup } from '@0x/dev-utils';
+import * as chai from 'chai';
+
+// Set up chai.
+chaiSetup.configure();
+export const expect = chai.expect;

contracts/test-utils/src/index.ts

@@ -1,5 +1,4 @@
 export { AbstractAssetWrapper } from './abstract_asset_wrapper';
-export { chaiSetup } from './chai_setup';
 export { constants } from './constants';
 export {
     expectContractCallFailedAsync,
@@ -46,3 +45,5 @@ export {
     Token,
     TransactionDataParams,
 } from './types';
+export { blockchainTests} from './mocha_blockchain';
+export { chaiSetup, expect } from './chai_setup';

contracts/test-utils/src/mocha_blockchain.ts

@@ -0,0 +1,130 @@
+import { BlockchainLifecycle } from '@0x/dev-utils';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import * as _ from 'lodash';
+import * as mocha from 'mocha';
+
+import { web3Wrapper } from './web3_wrapper';
+
+// tslint:disable: no-namespace only-arrow-functions no-unbound-method
+declare global {
+    export namespace Mocha {
+        export interface BlockchainSuiteState {
+            web3Wrapper: Web3Wrapper;
+            blockchainLifecycle: BlockchainLifecycle;
+        }
+
+        type BlockchainSuiteCallback = (this: ISuiteCallbackContext, state: BlockchainSuiteState) => void;
+        type SuiteCallback = (this: ISuiteCallbackContext) => void;
+        type BlockchainContextDefinitionCallback<T> = (description: string, callback: BlockchainSuiteCallback) => T;
+        type ContextDefinitionCallback<T> = (description: string, callback: SuiteCallback) => T;
+
+        interface BlockchainContextDefinition {
+            reset: {
+                only: BlockchainContextDefinitionCallback<ISuite>;
+                skip: BlockchainContextDefinitionCallback<void>;
+                (description: string, callback: BlockchainSuiteCallback): ISuite;
+            };
+            only: BlockchainContextDefinitionCallback<ISuite>;
+            skip: BlockchainContextDefinitionCallback<void>;
+            (description: string, callback: BlockchainSuiteCallback): ISuite;
+        }
+    }
+}
+
+// Singleton instance.
+let blockchainLifecycle: BlockchainLifecycle | undefined;
+
+function defineBlockchainSuite<T>(
+    description: string,
+    callback: Mocha.BlockchainSuiteCallback,
+    describeCall: Mocha.ContextDefinitionCallback<T>,
+): T {
+    init();
+    return describeCall(
+        description,
+        function(this: mocha.ISuiteCallbackContext): void {
+            callback.call(
+                this,
+                { web3Wrapper, blockchainLifecycle },
+            );
+        },
+    );
+}
+
+function defineResetSuite<T>(
+    description: string,
+    callback: Mocha.SuiteCallback,
+    describeCall: Mocha.ContextDefinitionCallback<T>,
+): T {
+    return describeCall(
+        description,
+        function(this: mocha.ISuiteCallbackContext): void {
+            if (blockchainLifecycle !== undefined) {
+                const _blockchainLifecycle = blockchainLifecycle;
+                beforeEach(async () => {
+                    return _blockchainLifecycle.startAsync();
+                });
+                afterEach(async () => {
+                    return _blockchainLifecycle.revertAsync();
+                });
+            }
+            callback.call(this);
+        },
+    );
+}
+
+function init(): void {
+    if (blockchainLifecycle !== undefined) {
+        return;
+    }
+    // Create the BlockchainLifecycle instance.
+    blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
+}
+
+/**
+ * Like mocha's `describe()`, but sets up a BlockchainLifecycle and Web3Wrapper.
+ */
+export const blockchainTests: Mocha.BlockchainContextDefinition = _.assign(
+    function(description: string, callback: Mocha.BlockchainSuiteCallback): Mocha.ISuite {
+        return defineBlockchainSuite(description, callback, describe);
+    },
+    {
+        only(description: string, callback: Mocha.BlockchainSuiteCallback): Mocha.ISuite {
+            return defineBlockchainSuite(description, callback, describe.only);
+        },
+        skip(description: string, callback: Mocha.BlockchainSuiteCallback): void {
+            return defineBlockchainSuite(description, callback, describe.skip);
+        },
+        reset: _.assign(
+            function(description: string, callback: Mocha.BlockchainSuiteCallback): Mocha.ISuite {
+                return defineBlockchainSuite(
+                    description,
+                    callback,
+                    function(_description: string, _callback: Mocha.SuiteCallback): Mocha.ISuite {
+                        return defineResetSuite(_description, _callback, describe);
+                    },
+                );
+            },
+            {
+                only(description: string, callback: Mocha.BlockchainSuiteCallback): Mocha.ISuite {
+                    return defineBlockchainSuite(
+                        description,
+                        callback,
+                        function(_description: string, _callback: Mocha.SuiteCallback): Mocha.ISuite {
+                            return defineResetSuite(_description, _callback, describe.only);
+                        },
+                    );
+                },
+                skip(description: string, callback: Mocha.BlockchainSuiteCallback): void {
+                    return defineBlockchainSuite(
+                        description,
+                        callback,
+                        function(_description: string, _callback: Mocha.SuiteCallback): void {
+                            return defineResetSuite(_description, _callback, describe.skip);
+                        },
+                    );
+                },
+            },
+        ),
+    },
+) as Mocha.BlockchainContextDefinition;

contracts/test-utils/src/test_with_reference.ts

@@ -1,10 +1,6 @@
-import * as chai from 'chai';
 import * as _ from 'lodash';
 
-import { chaiSetup } from './chai_setup';
-
-chaiSetup.configure();
-const expect = chai.expect;
+import { expect } from './chai_setup';
 
 class Value<T> {
     public value: T;