Exit with error if invalid Truffle JSON is encountered

mythril/support/truffle.py

@@ -1,5 +1,6 @@
 import os
 import re
+import sys
 import json
 from mythril.ether import util
 from mythril.ether.ethcontract import ETHContract
@@ -14,15 +15,22 @@ def analyze_truffle_project():
     
     build_dir = os.path.join(project_root, "build", "contracts")
 
-    contract_files = os.listdir(build_dir)
+    files = os.listdir(build_dir)
 
-    for contract_file in contract_files:
+    for filename in files:
 
-        with open(os.path.join(build_dir, contract_file)) as cf:
+        if re.match(r'.*\.json$', filename):
+
+            with open(os.path.join(build_dir, filename)) as cf:
                 contractdata = json.load(cf)
 
+            try:
                 name = contractdata['contractName']
                 bytecode = contractdata['deployedBytecode']
+            except:
+                print("Unable to parse contract data. Please use Truffle 4 to compile your project.")
+                sys.exit()
+
 
             if (len(bytecode) < 4):
                 continue
@@ -71,7 +79,6 @@ def analyze_truffle_project():
                     issue.code = source[mappings[index][0]: mappings[index][0] + mappings[index][1]]
 
 
-
             if len(report.issues):
                 print("Analysis result for " + name + ":\n" + report.as_text())
             else: