feat(@embark/test-runner): expose evmClientVersion for conditional tests

This commit introduces a new `global.getEvmVersion()` that can be used to
conditionally run tests, such as when tests rely on RPC APIs that are only
available in specific evm nodes.

dapps/tests/app/test/expiration_spec.js

@@ -19,6 +19,12 @@ contract("Expiration", function() {
   });
 
   it("should have expired after skipping time", async function () {
+    const client = await getEvmVersion();
+
+    if (client.indexOf('EthereumJS TestRPC') === -1) {
+      console.info(`Skipping test because it requires the use of Ganache. Current blockchain client: ${client}`);
+      return assert.ok(true);
+    }
     await mineAtTimestamp(now + 1001); // sets block.timestamp to 1001
     const isExpired = await Expiration.methods.isExpired().call();
     assert.strictEqual(isExpired, true);

packages/plugins/mocha-tests/src/lib/index.js

@@ -155,6 +155,7 @@ class MochaTestRunner {
     const provider = await this.events.request2("tests:blockchain:start", this.options);
     this.web3 = new Web3(provider);
     accounts = await this.web3.eth.getAccounts();
+
     await events.request2("contracts:reset");
     let contractFiles = await events.request2("config:contractsFiles");
 

packages/stack/test-runner/src/lib/index.js

@@ -17,6 +17,7 @@ const reports = require('istanbul-reports');
 const Reporter = require('./reporter');
 
 const EMBARK_OPTION = 'embark';
+const GANACHE_CLIENT_VERSION_NAME = "EthereumJS TestRPC";
 
 class TestRunner {
   constructor(embark, options) {
@@ -137,6 +138,7 @@ class TestRunner {
   }
 
   setupGlobalVariables() {
+
     assert.reverts = async function(method, params = {}, message) {
       if (typeof params === 'string') {
         message = params;
@@ -175,18 +177,30 @@ class TestRunner {
       }
     };
 
-    global.assert = assert;
+    global.getEvmVersion = async () => {
+      return this.evmMethod('web3_clientVersion');
+    };
 
+    global.assert = assert;
     global.embark = this.embark;
 
     global.increaseTime = async (amount) => {
+      const evmVersion = await global.getEvmVersion();
+
+      if (evmVersion.indexOf(GANACHE_CLIENT_VERSION_NAME) === -1) {
+        this.logger.warn('WARNING: global.increaseTime uses RPC APIs that are only provided by a simulator (Ganache) and might cause a timeout');
+      }
       await this.evmMethod("evm_increaseTime", [Number(amount)]);
       await this.evmMethod("evm_mine");
     };
 
     // Mines a block and sets block.timestamp accordingly.
     // See https://github.com/trufflesuite/ganache-core/pull/13 for more information
     global.mineAtTimestamp = async (timestamp) => {
+      const evmVersion = await global.getEvmVersion();
+      if (evmVersion.indexOf(GANACHE_CLIENT_VERSION_NAME) === -1) {
+        this.logger.warn('WARNING: global.mineAtTimestamp uses RPC APIs that are only provided by a simulator (Ganache) and might cause a timeout');
+      }
       return this.evmMethod("evm_mine", [parseFloat(timestamp)]);
     };
   }