ALLOW platform specific url patterns

src/common.js

@@ -70,6 +70,32 @@ function validateConfiguration({ version, goBinary }) {
   }
 }
 
+function getUrl(url, process) {
+  if (typeof url === 'string') {
+      return url;
+  }
+
+  let _url;
+
+  if (url[process.platform]) {
+      _url = url[process.platform];
+  } else {
+      _url = url.default;
+  }
+
+  if (typeof _url === 'string') {
+      return _url;
+  }
+
+  if (_url[process.arch]) {
+      _url = _url[process.arch]
+  } else {
+      _url = _url.default;
+  }
+
+  return _url;
+}
+
 function parsePackageJson() {
   if (!(process.arch in ARCH_MAPPING)) {
     console.error('Installation is not supported for this architecture: ' + process.arch);
@@ -99,9 +125,14 @@ function parsePackageJson() {
   // We have validated the config. It exists in all its glory
   const binPath = packageJson.goBinary.path;
   let binName = packageJson.goBinary.name;
-  let url = packageJson.goBinary.url;
+  let url = getUrl(packageJson.goBinary.url, process);
   let version = packageJson.version;
 
+  if (!url) {
+    console.error('Could not find url matching platform and architecture');
+    return
+  }
+
   if (version[0] === 'v') version = version.substr(1);  // strip the 'v' if necessary v0.0.1 => 0.0.1
 
   // Binary name on Windows has .exe suffix
@@ -127,4 +158,4 @@ function parsePackageJson() {
   };
 }
 
-module.exports = { parsePackageJson, getInstallationPath };
+module.exports = { parsePackageJson, getUrl, getInstallationPath };