Small fixes

lib/Connection.js

@@ -20,7 +20,7 @@ class Connection {
 
     this._openRequests = 0
     this._status = opts.status || Connection.statuses.ALIVE
-    this.roles = Object.assign({}, defaultRoles, opts.roles) || Object.assign({}, defaultRoles)
+    this.roles = Object.assign({}, defaultRoles, opts.roles)
 
     if (!['http:', 'https:'].includes(this.url.protocol)) {
       throw new ConfigurationError(`Invalid protocol: '${this.url.protocol}'`)
@@ -104,6 +104,7 @@ class Connection {
     // starts the request
     if (isStream(params.body) === true) {
       pump(params.body, request, err => {
+        /* istanbul ignore if  */
         if (err != null && ended === false) {
           ended = true
           this._openRequests--
@@ -129,14 +130,13 @@ class Connection {
   }
 
   setRole (role, enabled) {
-    assert(
-      ~validRoles.indexOf(role),
-      `Unsupported role: '${role}'`
-    )
-    assert(
-      typeof enabled === 'boolean',
-      'enabled should be a boolean'
-    )
+    if (validRoles.indexOf(role) === -1) {
+      throw new ConfigurationError(`Unsupported role: '${role}'`)
+    }
+    if (typeof enabled !== 'boolean') {
+      throw new ConfigurationError('enabled should be a boolean')
+    }
+
     this.roles[role] = enabled
     return this
   }

lib/Transport.js

@@ -185,6 +185,7 @@ class Transport {
       // collect the payload
       response.setEncoding('utf8')
       response.on('data', chunk => { payload += chunk })
+      /* istanbul ignore next */
       response.on('error', err => {
         const error = new ConnectionError(err.message, params)
         this.emit('response', error, meta)