refactor(lib/Error): remove unused branches (#302)

Author: michael-ciniawsky

lib/Error.js

@@ -4,18 +4,11 @@ class SyntaxError extends Error {
   constructor (err) {
     super(err)
 
-    this.err = err.input.source
-
     this.name = 'Syntax Error'
-    this.message = ''
 
-    if (err.line) {
-      this.message += `${this.name} \n\n(${err.line}:${err.column}) ${err.reason}`
-    }
-
-    if (err.input.source) {
-      this.message += `\n\n${err.showSourceCode()}\n`
-    }
+    this.message = ''
+    this.message += `${this.name} \n\n(${err.line}:${err.column}) ${err.reason}`
+    this.message += `\n\n${err.showSourceCode()}\n`
 
     this.stack = false
   }