test: re-use static build directory for caching between test runs, fixes ConsenSys-archive/truffle#343

Author: Zolmeister

lib/commands/test.js

@@ -4,6 +4,7 @@ var command = {
   builder: {},
   run: function (options, done) {
     var OS = require("os");
+    var path = require('path');
     var dir = require("node-dir");
     var temp = require("temp");
     var Config = require("truffle-config");
@@ -43,12 +44,25 @@ var command = {
       dir.files(config.test_directory, callback);
     };
 
+    function getTempDir(name, cb) {
+      var temporaryDirectory = path.join(temp.dir, name);
+
+      if (fs.existsSync(temporaryDirectory))
+        cb(null, temporaryDirectory);
+      else
+        fs.mkdir(temporaryDirectory, function (err) {
+          if (err)
+            return cb(err);
+          cb(null, temporaryDirectory);
+        })
+    }
+
     getFiles(function(err, files) {
       files = files.filter(function(file) {
         return file.match(config.test_file_extension_regexp) != null;
       });
 
-      temp.mkdir('test-', function(err, temporaryDirectory) {
+      getTempDir('contracts_build_directory', function (err, temporaryDirectory) {
         if (err) return done(err);
 
         function cleanup() {