add dev dependencies on codecept and allure to allow IDE to resolve those calls.

Replace fs.writeFile with fs.writeFileSync to ensure the diff image is written before attached to allure.
Fix JSDoc warnings
Fix "err" scoping warning
Change undefined checks to check if element is either null or undefined
Remove unused parameter
Add check to ensure size is populated
fix overcomplicated ternary statement

Author: s_ashiotis

index.js

@@ -34,7 +34,7 @@ class ResembleHelper extends Helper {
    * @param image
    * @param diffImage
    * @param options
-   * @returns {Promise<any | never>}
+   * @returns {Promise<resolve | reject>}
    */
   async _compareImages(image, diffImage, options) {
     const image1 = this.baseFolder + image;
@@ -76,17 +76,12 @@ class ResembleHelper extends Helper {
           }
           resolve(data);
           if (data.misMatchPercentage >= tolerance) {
-            mkdirp(getDirName(this.diffFolder + diffImage), function (err) {
-              if (err) return cb(err);
-            });
-            fs.writeFile(this.diffFolder + diffImage + '.png', data.getBuffer(), (err, data) => {
-              if (err) {
-                throw new Error(this.err);
-              } else {
-                const diffImagePath = path.join(process.cwd(), this.diffFolder + diffImage + '.png');
-                this.debug("Diff Image File Saved to: " + diffImagePath);
-              }
+            mkdirp(getDirName(this.diffFolder + diffImage), function (error) {
+              if (error) return cb(error);
             });
+            fs.writeFileSync(this.diffFolder + diffImage + '.png', data.getBuffer());
+            const diffImagePath = path.join(process.cwd(), this.diffFolder + diffImage + '.png');
+            this.debug("Diff Image File Saved to: " + diffImagePath);
           }
         }
       });
@@ -179,9 +174,9 @@ class ResembleHelper extends Helper {
         Key: `output/${baseImage}`,
         Body: base64data
       };
-      s3.upload(params, (uerr, data) => {
-        if (uerr) throw uerr;
-        console.log(`Screenshot Image uploaded successfully at ${data.Location}`);
+      s3.upload(params, (uErr, uData) => {
+        if (uErr) throw uErr;
+        console.log(`Screenshot Image uploaded successfully at ${uData.Location}`);
       });
     });
     fs.readFile(this.diffFolder + "Diff_" + baseImage, (err, data) => {
@@ -193,9 +188,9 @@ class ResembleHelper extends Helper {
           Key: `diff/Diff_${baseImage}`,
           Body: base64data
         };
-        s3.upload(params, (uerr, data) => {
-          if (uerr) throw uerr;
-          console.log(`Diff Image uploaded successfully at ${data.Location}`)
+        s3.upload(params, (uErr, uData) => {
+          if (uErr) throw uErr;
+          console.log(`Diff Image uploaded successfully at ${uData.Location}`)
         });
       }
     });
@@ -209,9 +204,9 @@ class ResembleHelper extends Helper {
             Key: `base/${baseImage}`,
             Body: base64data
           };
-          s3.upload(params, (uerr, data) => {
-            if (uerr) throw uerr;
-            console.log(`Base Image uploaded at ${data.Location}`)
+          s3.upload(params, (uErr, uData) => {
+            if (uErr) throw uErr;
+            console.log(`Base Image uploaded at ${uData.Location}`)
           });
         }
       });
@@ -241,7 +236,7 @@ class ResembleHelper extends Helper {
       Bucket: bucketName,
       Key: `base/${baseImage}`
     };
-    return new Promise((resolve, reject) => {
+    return new Promise((resolve) => {
       s3.getObject(params, (err, data) => {
         if (err) console.error(err);
         console.log(this.baseFolder + baseImage);
@@ -258,32 +253,7 @@ class ResembleHelper extends Helper {
    * @returns {Promise<void>}
    */
   async seeVisualDiff(baseImage, options) {
-    if (options == undefined) {
-      options = {};
-      options.tolerance = 0;
-    }
-
-    const awsC = this.config.aws;
-
-    if (awsC !== undefined && options.prepareBaseImage === false) {
-      await this._download(awsC.accessKeyId, awsC.secretAccessKey, awsC.region, awsC.bucketName, baseImage);
-    }
-
-    if (options.prepareBaseImage !== undefined && options.prepareBaseImage) {
-      await this._prepareBaseImage(baseImage);
-    }
-
-    const misMatch = await this._fetchMisMatchPercentage(baseImage, options);
-
-    this._addAttachment(baseImage, misMatch, options.tolerance);
-
-    if (awsC !== undefined) {
-      let ifUpload = options.prepareBaseImage === false ? false : true;
-      await this._upload(awsC.accessKeyId, awsC.secretAccessKey, awsC.region, awsC.bucketName, baseImage, ifUpload)
-    }
-
-    this.debug("MisMatch Percentage Calculated is " + misMatch);
-    assert(misMatch <= options.tolerance, "MissMatch Percentage " + misMatch);
+    await this._assertVisualDiff(undefined, baseImage, options);
   }
 
   /**
@@ -295,8 +265,11 @@ class ResembleHelper extends Helper {
    * @returns {Promise<void>}
    */
   async seeVisualDiffForElement(selector, baseImage, options) {
+    await this._assertVisualDiff(selector, baseImage, options);
+  }
 
-    if (options == undefined) {
+  async _assertVisualDiff(selector, baseImage, options) {
+    if (!options) {
       options = {};
       options.tolerance = 0;
     }
@@ -311,14 +284,16 @@ class ResembleHelper extends Helper {
       await this._prepareBaseImage(baseImage);
     }
 
-    options.boundingBox = await this._getBoundingBox(selector);
+    if (selector) {
+      options.boundingBox = await this._getBoundingBox(selector);
+    }
+
     const misMatch = await this._fetchMisMatchPercentage(baseImage, options);
 
     this._addAttachment(baseImage, misMatch, options.tolerance);
 
     if (awsC !== undefined) {
-      let ifUpload = options.prepareBaseImage === false ? false : true;
-      await this._upload(awsC.accessKeyId, awsC.secretAccessKey, awsC.region, awsC.bucketName, baseImage, ifUpload)
+      await this._upload(awsC.accessKeyId, awsC.secretAccessKey, awsC.region, awsC.bucketName, baseImage, options.prepareBaseImage)
     }
 
     this.debug("MisMatch Percentage Calculated is " + misMatch);
@@ -390,6 +365,10 @@ class ResembleHelper extends Helper {
       size = await helper.browser.getElementSize(selector);
     }
 
+    if (!size) {
+      throw new Error("Cannot get element size!");
+    }
+
     const bottom = size.height + location.y;
     const right = size.width + location.x;
     const boundingBox = {

package.json

@@ -16,6 +16,10 @@
     "aws-sdk": "^2.476.0",
     "image-size": "^0.7.4"
   },
+  "devDependencies": {
+    "allure-commandline": "^2.13.0",
+    "codeceptjs": "^2.3.5"
+  },
   "keywords": [
     "codeceptJS",
     "codeceptjs",