Add EADDRINUSE test (#404)

lib/app.js

@@ -293,7 +293,8 @@ class App {
       return vm;
     }
 
-    await pify(this.server.listen)(this.port);
+    // NB: EADDRINUSE errors are uncatch-able?
+    pify(this.server.listen)(this.port);
   }
 
   assertHasBlockchain(provider){

lib/ui.js

@@ -100,10 +100,6 @@ class AppUI extends UI {
       'istanbul-fail': `${c.red('Istanbul coverage reports could not be generated. ')}`,
 
       'sources-fail': `${c.red('Cannot locate expected contract sources folder: ')} ${args[0]}`,
-
-      'server-fail': `${c.red('Could not launch ganache server. Is ')}` +
-                     `${args[0]} ${c.red('already in use? ')}` +
-                     `${c.red('Run "lsof -i" in your terminal to check.\n')}`,
     }
 
     return this._format(kinds[kind])

test/units/truffle/errors.js

@@ -1,7 +1,9 @@
 const assert = require('assert');
 const fs = require('fs');
 const path = require('path')
+const pify = require('pify')
 const shell = require('shelljs');
+const ganache = require('ganache-core-sc');
 
 const verify = require('../../util/verifiers')
 const mock = require('../../util/integration.truffle');
@@ -123,6 +125,26 @@ describe('Truffle Plugin: error cases', function() {
     }
   });
 
+  // This case *does* throw an error, but it's uncatch-able;
+  it.skip('tries to launch with a port already in use', async function(){
+    verify.cleanInitialState();
+    const server = ganache.server();
+
+    truffleConfig.network = 'development';
+    mock.install('Simple', 'simple.js', solcoverConfig);
+
+    await pify(server.listen)(8545);
+
+    try {
+      await plugin(truffleConfig);
+      assert.fail();
+    } catch(err){
+      assert(err.message.includes('EADDRINUSE: address already in use :::8545'))
+    }
+
+    await pify(server.close)();
+  });
+
   // Truffle test contains syntax error
   it('truffle crashes', async function() {
     verify.cleanInitialState();