refactor(Warning): add warning property checks

src/Warning.js

@@ -10,12 +10,19 @@
  */
 class Warning extends Error {
   constructor (warning) {
-    super()
+    super(warning)
 
     const { text, line, column } = warning
 
-    this.name = 'LoaderWarning'
-    this.message = `\n(${line}:${column}) ${text}\n`
+    this.name = 'Warning'
+
+    this.message = `${this.name}\n\n`
+
+    if (typeof line !== 'undefined') {
+      this.message += `(${line}:${column}) `
+    }
+
+    this.message += `${text}`
 
     this.stack = false
   }

test/__snapshots__/Warnings.test.js.snap

@@ -1,7 +1,7 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`Warnings Plugins 1`] = `
-"
-(1:5) <Message>
-"
+"Warning
+
+(1:5) <Message>"
 `;