move determine test contracts into own method in waterfall

index.js

@@ -18,6 +18,10 @@ var runTestFiles = function(filepath, isDirectory, web3) {
           next(err)
         }
 
+        next(null, compilationResult, contracts)
+      })
+    },
+    function determineTestContractsToRun(compilationResult, contracts, next) {
       let contractsToTest = []
       if (isDirectory) {
         fs.readdirSync(filepath).forEach(filename => {
@@ -33,7 +37,6 @@ var runTestFiles = function(filepath, isDirectory, web3) {
       }
 
       next(null, contractsToTest, contracts)
-      })
     },
     function runTests (contractsToTest, contracts, next) {
       var testCallback = function (result) {