Error handling and css fonts in Selenium extensions

See merge request nexedi/erp5!1220

bt5/erp5_ui_test_core/SkinTemplateItem/portal_skins/erp5_ui_test_core/user-extensions.js.js

@@ -2,6 +2,56 @@
  * Selenium extensions for the ERP5 project
  */
 
+/**
+ * Wrap a promise to make it usable by selenium commands.
+ *
+ * If the promise is rejected, the command will fail with the promise rejection value.
+ * If the promise is resovled, the resolved value is not used.
+ *
+ * The asynchronicity of do* method is as follow Selenium.prototype.doXXX
+ * returns a function and this function will be called again and again until:
+ *   * function returns true, which means step is successfull
+ *   * function returns false, which means step is not finished and function will be called again
+ *   * an execption is raised, in that case the step is failed
+ *   * global timeout is reached.
+ * we implement the state management with similar approach as what's discussed
+ * https://stackoverflow.com/questions/30564053/how-can-i-synchronously-determine-a-javascript-promises-state
+ *
+ * @param {Promise} promise the promise to await
+ * @returns {() => boolean}
+*/
+function wrapPromise(promise) {
+  /** @type {'pending' | 'resolved' | 'rejected'} */
+  var promiseState;
+  var rejectionValue;
+  return () => {
+    if (promiseState === 'pending') {
+      return false;
+    }
+    if (promiseState === 'resolved') {
+      return true;
+    }
+    if (promiseState === 'rejected') {
+      Assert.fail("" + rejectionValue);
+      return true
+    }
+
+    promise.then(
+      function () {
+        promiseState = 'resolved';
+      }).catch(
+        function (error) {
+          console.error(error);
+          promiseState = 'rejected';
+          rejectionValue = error;
+        }
+      );
+    promiseState = 'pending';
+    return false;
+  }
+}
+
+
 /**
  * You can set file data to file input field without security error.
  *   <tr>
@@ -9,30 +59,21 @@
  *    <td>field_my_file</td>
  *    <td>/data.jpg myfilename.jpg</td>
  *  </tr>
+ *
+ * @param {string} locator the selenium locator
+ * @param {string} url_and_filename the URL and filename, separated by space
+ * @returns {() => boolean}
  */
 Selenium.prototype.doSetFile = function(locator, url_and_filename) {
   var tmpArray = url_and_filename.split(' ', 2);
   var url = tmpArray[0];
   var fileName = tmpArray[1];
-  var rejectionValue,
-    promiseState;
-  // same technique as doVerifyImageMatchSnapshot below
-  var assertFileSet = () => {
-    if (promiseState === 'pending') {
-      return false;
-    }
-    if (promiseState === 'resolved') {
-      return true;
-    }
-    if (promiseState === 'rejected') {
-      Assert.fail(rejectionValue);
-    }
-    promiseState = 'pending';
 
   if (!fileName) {
     throw new Error('file name must not be empty.');
   }
   var fileField = this.page().findElement(locator);
+  return wrapPromise(
     fetch(url)
       .then(function(response) {
         if (!response.ok) {
@@ -48,19 +89,7 @@ Selenium.prototype.doSetFile = function(locator, url_and_filename) {
           new DataTransfer();
         dT.items.add(new File([blob], fileName));
         fileField.files = dT.files;
-      })
-      .then(
-        function() {
-          promiseState = 'resolved';
-        },
-        function(error) {
-          console.error(error);
-          promiseState = 'rejected';
-          rejectionValue = 'Error setting file ' + error;
-        }
-      );
-  }
-  return assertFileSet;
+      }));
 };
 
 
@@ -157,10 +186,10 @@ function getReferenceImageURL(testPathName) {
  * Helper function to generate a DOM elements
  *
  * @param {string} tagName name of the element
- * @param {Node?} childList list of child elements
- * @param {Map<string,any>?} attributeDict attributes
- * @param {string?} textContent
- * @return {Node}
+ * @param {Node[]} [childList] list of child elements
+ * @param {Object} [attributeDict] attributes
+ * @param {string} [textContent]
+ * @return {HTMLElement}
  */
 function generateElement(tagName, childList, attributeDict, textContent) {
   var element = document.createElement(tagName);
@@ -174,6 +203,9 @@ function generateElement(tagName, childList, attributeDict, textContent) {
       element.appendChild(child);
     });
   }
+  if (textContent) {
+    element.textContent = textContent;
+  }
   return element;
 }
 
@@ -248,49 +280,41 @@ function generateUpdateForm(referenceImageURL, newImageData) {
 /**
  * verify that the rendering of the element `locator` matches the previously saved reference.
  *
- * Arguments:
- *   locator - an element locator
- *   misMatchTolerance - the percentage of mismatch allowed. If this is 0, the
+ * Note that this is implemented as do* method and not a assert* method because only do* methods are asynchronous.
+ *
+ * @param {string} locator - an element locator
+ * @param {string} misMatchTolerance - the percentage of mismatch allowed. If this is 0, the
  *      images must be exactly same. If more than 0, image will also be resized.
+ * @returns {() => boolean}
  */
 Selenium.prototype.doVerifyImageMatchSnapshot = (
   locator,
   misMatchTolerance
 ) => {
-  // XXX this is a do* method and not a assert* method because only do* methods are
-  // asynchronous.
-  // The asynchronicity of do* method is as follow Selenium.prototype.doXXX
-  // returns a function and this function will be called again and again until:
-  //   * function returns true, which means step is successfull
-  //   * function returns false, which means step is not finished and function will be called again
-  //   * an execption is raised, in that case the step is failed
-  //   * global timeout is reached.
-  // we implement the state management with similar approach as what's discussed
-  // https://stackoverflow.com/questions/30564053/how-can-i-synchronously-determine-a-javascript-promises-state
-  var promiseState, rejectionValue, canvasPromise;
-  return function assertCanvasImage() {
-    if (promiseState === 'pending') {
-      return false;
-    }
-    if (promiseState === 'resolved') {
-      return true;
-    }
-    if (promiseState === 'rejected') {
-      Assert.fail(rejectionValue);
+  var misMatchToleranceFloat = parseFloat(misMatchTolerance);
+  if (isNaN(misMatchToleranceFloat)) {
+    misMatchToleranceFloat = 0;
   }
 
-    misMatchTolerance = parseFloat(misMatchTolerance);
-    if (isNaN(misMatchTolerance)) {
-      misMatchTolerance = 0;
-    }
-    promiseState = 'pending';
-    element = selenium.browserbot.findElement(locator);
+  /** @type {Promise<HTMLCanvasElement>} */
+  var canvasPromise;
+
+  /** @type {HTMLElement} */
+  var element = selenium.browserbot.findElement(locator);
+
   if (element.nodeName == 'CANVAS' /* instanceof HTMLCanvasElement XXX ? */) {
     canvasPromise = Promise.resolve(element);
   } else {
-      canvasPromise = html2canvas(element);
+    // create a canvas in the same document, so that if this document has loaded
+    // extra fonts they are also available.
+    // As suggested on https://github.com/niklasvh/html2canvas/issues/1772
+    var destinationCanvas = element.ownerDocument.createElement("canvas");
+    destinationCanvas.width = element.scrollWidth;
+    destinationCanvas.height = element.scrollHeight;
+    canvasPromise = html2canvas(element, { canvas: destinationCanvas });
   }
 
+  return wrapPromise(
     canvasPromise
       .then(canvas => {
         return canvas.toDataURL();
@@ -310,12 +334,12 @@ Selenium.prototype.doVerifyImageMatchSnapshot = (
             blob => {
               return new Promise((resolve, reject) => {
                 var fr = new FileReader();
-                fr.onload = d => resolve(fr.result);
+                fr.onload = () => resolve(fr.result);
                 fr.onerror = reject;
                 fr.readAsDataURL(blob);
               });
             },
-            e => {
+            () => {
               // fetching reference was not found, return empty image instead, it will be different
               // (unless the tolerance is too high)
               return document.createElement('canvas').toDataURL();
@@ -328,16 +352,14 @@ Selenium.prototype.doVerifyImageMatchSnapshot = (
                   useCrossOrigin: false
                 })
                 .compareTo(expected);
-              if (misMatchTolerance > 0) {
+              if (misMatchToleranceFloat > 0) {
                 comparator = comparator.scaleToSameSize();
               }
               comparator.onComplete(resolve);
             });
           })
           .then(diff => {
-            if (diff.rawMisMatchPercentage <= misMatchTolerance) {
-              promiseState = 'resolved';
-            } else {
+            if (diff.rawMisMatchPercentage > misMatchToleranceFloat) {
               return generateUpdateForm(referenceImageURL, actual).then(
                 updateReferenceImageForm => {
                   htmlTestRunner.currentTest.currentRow.trElement
@@ -364,19 +386,11 @@ Selenium.prototype.doVerifyImageMatchSnapshot = (
                         )
                       ])
                     );
-
-                  promiseState = 'rejected';
-                  rejectionValue =
-                    'Images are ' + diff.misMatchPercentage + '% different';
+                  throw new Error('Images are ' + diff.misMatchPercentage + '% different');
                 }
               );
             }
           });
-      })
-      .catch(error => {
-        console.error(error);
-        promiseState = 'rejected';
-        rejectionValue = 'Error computing image differences ' + error;
-      });
-  };
+      }));
+
 };