support mapping contract file in contracts config

lib/core/config.js

@@ -47,6 +47,7 @@ Config.prototype.loadConfigFiles = function(options) {
   this.loadPipelineConfigFile();
 
   this.loadContractsConfigFile();
+  this.loadExternalContractsFiles();
   this.loadWebServerConfigFile();
   this.loadChainTrackerFile();
   this.loadPluginContractFiles();
@@ -60,6 +61,7 @@ Config.prototype.reloadConfig = function() {
   this.loadContractsConfigFile();
   this.loadPipelineConfigFile();
   this.loadContractsConfigFile();
+  this.loadExternalContractsFiles();
   this.loadChainTrackerFile();
 };
 
@@ -140,6 +142,16 @@ Config.prototype.loadContractsConfigFile = function() {
   this.contractsConfig = this._mergeConfig(configFilePath, configObject, this.env);
 };
 
+Config.prototype.loadExternalContractsFiles = function() {
+  let contracts = this.contractsConfig.contracts;
+  for (let contractName in contracts) {
+    let contract = contracts[contractName];
+    if (contract.file) {
+      this.contractsFiles.push(new File({filename: contract.file, type: "dapp_file", basedir: '', path: contract.file}));
+    }
+  }
+};
+
 Config.prototype.loadStorageConfigFile = function() {
   var versions = utils.recursiveMerge({"ipfs-api": "17.2.4"}, this.embarkConfig.versions || {});
 

test_apps/test_app/config/contracts.json

@@ -62,6 +62,12 @@
           ["$MyToken2", "$SimpleStorage"],
           100
         ]
+      },
+      "SimpleStorageTest": {
+        "file": "./some_folder/test_contract.sol",
+        "args": [
+          1000
+        ]
       }
     },
     "afterDeploy": [