Fix: improve Vue file detection

eslint-plugin-import seems to not give filenames.

Author: mysticatea

lib/parse-component.js

@@ -21,6 +21,8 @@ const transformHtml = require("./transform-html")
 // Helpers
 //------------------------------------------------------------------------------
 
+const STARTS_WITH_LT = /^\s*</
+
 /**
  * Parse the given component.
  *
@@ -138,7 +140,9 @@ function parse(code, options) {
     const filePath = options.filePath
     const scriptOptions = options
     const templateOptions = options.template || {}
-    const isVue = path.extname(filePath || "unknown.js") === ".vue"
+    const isVue =
+        path.extname(filePath || "unknown.js") === ".vue" ||
+        STARTS_WITH_LT.test(code)
     const scriptParser = new ScriptParser(code, scriptOptions)
     let ast = null