added fs-extra to have ensure-dir for non existing dirs

bin/testrunner.js

@@ -7,7 +7,8 @@
  */
 
 const puppeteer = require('puppeteer');
-const fs = require("fs")
+const fs_bare = require("fs") // required for fs-extra
+const fs = require("fs-extra")
 const path = require("path")
 const start_dir = process.cwd()
 const start_file = path.join(start_dir,"lib","index.html")
@@ -39,18 +40,24 @@ async function makeScreenshot(href){
     page.once("load",logPageEvent)
 
     await page.goto(href)
+    href = href.replace("file:///","")
     const fname = path.parse(href).name
-
+    let fpath
     if (fname != "index"){
         image_url = href.replace(fname + ".html" ,"thumbnails/" + fname + ".png")
+        fpath = href.replace(fname + ".html", "thumbnails")
     }
     else{
         image_url = href.replace(fname + ".html" ,"thumbnail.png")
+        fpath = href.replace(fname + ".html", "")
     }
-    image_url = image_url.replace("file:///","")
+    // image_url = image_url.replace("file:///","")
+    // fpath = fpath.replace("file:///","")
     
     page.removeAllListeners()
     
+    fs.ensureDir(fpath)
+
     await page.screenshot({path: image_url});
     await browser.close();
 }