Add option to display invalid constraints on form validation in console

lib/api.js

@@ -214,6 +214,8 @@ function transformOptions(options, encoding, mimeType) {
       pretendToBeVisual: false,
       storageQuota: 5000000,
 
+      _reportInvalidConstraintsToConsole: false,
+
       // Defaults filled in later
       resourceLoader: undefined,
       virtualConsole: undefined,
@@ -283,6 +285,10 @@ function transformOptions(options, encoding, mimeType) {
     transformed.windowOptions.storageQuota = Number(options.storageQuota);
   }
 
+  if (options._reportInvalidConstraintsToConsole !== undefined) {
+    transformed.windowOptions._reportInvalidConstraintsToConsole = Boolean(options._reportInvalidConstraintsToConsole);
+  }
+
   return transformed;
 }
 

lib/jsdom/browser/Window.js

@@ -282,6 +282,8 @@ function Window(options) {
 
   this._runScripts = options.runScripts;
 
+  this._reportInvalidConstraintsToConsole = options._reportInvalidConstraintsToConsole;
+
   // Set up the window as if it's a top level window.
   // If it's not, then references will be corrected by frame/iframe code.
   this._parent = this._top = this._globalProxy;

lib/jsdom/living/nodes/HTMLFormElement-impl.js

@@ -224,7 +224,13 @@
     }
 
     const unhandledInvalidControls = [];
     for (const invalidControl of invalidControls) {
+
+      // Report form validation errors to the console for developers debugging why their forms are not submited in tests
+      if(window._reportInvalidConstraintsToConsole){ 
+        console.error("Form validation failed for "+invalidControl.outerHTML+" with the value: "+ JSON.stringify(invalidControl.value));
+      }
+
       const notCancelled = fireAnEvent("invalid", invalidControl, undefined, { cancelable: true });
       if (notCancelled) {
         unhandledInvalidControls.push(invalidControl);