Update base.ts to accept functions for folder name

docs/OPTIONS.md

@@ -18,11 +18,21 @@ The padding that needs to be added to the address bar on iOS and Android to do a
 If no baseline image is found during the comparison the image is automatically copied to the baseline folder when this is set to `true`
 
 ### `baselineFolder`
-- **Type:** `string`
+- **Type:** `any`
 - **Mandatory:** No
 - **Default:** `./wic/baseline/`
 
-The directory that will hold all the baseline images that are used to during the comparison.
+The directory that will hold all the baseline images that are used to during the comparison. If not set, the default value will be used. A function that accepts an option object can also be used to set the baselineFolder value:
+```
+  getFolder = type = options => {
+    const testFolder = path.dirname(options.specs[0]);
+    return path.join(testFolder, 'snapshots', type);
+  };
+
+  {
+    baselineFolder: getFolder(options)
+  }
+```
 
 ### `clearRuntimeFolder`
 - **Type:** `boolean`
@@ -90,11 +100,22 @@ Hide scrollbars in the application. If set to true all scrollbars will be disabl
 Save the images per instance in a separate folder so for example all Chrome screenshots will be saved in a chrome folder like `desktop_chrome`.
 
 ### `screenshotPath`
-- **Type:** `string`
+- **Type:** `any`
 - **Default:** `.tmp/`
 - **Mandatory:** no
 
-The directory that will hold all the actual / difference screenshots
+The directory that will hold all the actual / difference screenshots. If not set, the default value will be used. A function that ac
+cepts an option object can also be used to set the screenshotPath value:
+```
+  getFolder = type = options => {
+    const testFolder = path.dirname(options.specs[0]);
+    return path.join(testFolder, 'snapshots', type);
+  };
+
+  {
+    screenshotPath: getFolder(options)
+  }
+```
 
 ### `toolBarShadowPadding`
 - **Type:** `number`

lib/base.interface.ts

@@ -1,5 +1,5 @@
 export interface Folders {
   actualFolder: string;   // The actual folder where the current screenshots need to be saved
-  baselineFolder: string; // The baseline folder where the baseline screenshots can be found
+  baselineFolder: any; // The baseline folder where the baseline screenshots can be found
   diffFolder: string;     // The diff folder where the differences are saved
 }

lib/base.spec.ts

@@ -13,6 +13,23 @@ describe('BaseClass', () => {
     expect(instance.folders.diffFolder).toBe('../my_folder/screenshots/diff');
   });
 
+  it('should be able to create baselineFolder with a function', () => {
+    const options = {
+      baseline: './subfolder//../baseline',
+      screenshot: './../my_folder//screenshots'
+    };
+    const setPath = (folderPath: any) => {
+      return folderPath;
+    };
+    const instance = new BaseClass({
+      baselineFolder: setPath(options.baseline),
+      screenshotPath: setPath(options.screenshot)
+    });
+    expect(instance.folders.actualFolder).toBe('../my_folder/screenshots/actual');
+    expect(instance.folders.baselineFolder).toBe('baseline');
+    expect(instance.folders.diffFolder).toBe('../my_folder/screenshots/diff');
+  });  
+
   it('should be able to create BaseClass with default options', () => {
     const instance = new BaseClass({});
     expect(instance.folders.actualFolder).toBe('.tmp/actual');

lib/base.ts

@@ -13,8 +13,20 @@ export default class BaseClass {
     // determine default options
     this.defaultOptions = defaultOptions(options);
 
-    const baselineFolder = normalize(options.baselineFolder || FOLDERS.DEFAULT.BASE);
-    const baseFolder = normalize(options.screenshotPath || FOLDERS.DEFAULT.SCREENSHOTS);
+    let baselineFolder;
+    let baseFolder;
+
+    if (typeof options.baselineFolder === 'function') {
+      baselineFolder = options.baselineFolder(options);
+    } else {
+      baselineFolder = normalize(options.baselineFolder || FOLDERS.DEFAULT.BASE);
+    }
+
+    if (typeof options.screenshotPath === 'function') {
+      baseFolder = options.screenshotPath(options);
+    } else {
+      baseFolder = normalize(options.screenshotPath || FOLDERS.DEFAULT.SCREENSHOTS);
+    }
 
     this.folders = {
       actualFolder: join(baseFolder, FOLDERS.ACTUAL),

lib/helpers/options.interface.ts

@@ -7,7 +7,7 @@ export interface ClassOptions{
   // If no baseline image is found during the comparison the image is automatically copied to the baseline folder when this is set to `true`
   autoSaveBaseline?: boolean;
   // The directory that will hold all the baseline images that are used to during the comparison
-  baselineFolder?: string;
+  baselineFolder?: any;
   // Delete runtime folder (actual & diff) on initialisation
   clearRuntimeFolder?: boolean;
   // Enable extra console logging or always saving the diff images during comparison
@@ -17,7 +17,7 @@ export interface ClassOptions{
   // Save the images per instance in a separate folder.
   savePerInstance?: boolean;
   // The directory that will hold all the actual / difference screenshots
-  screenshotPath?: string;
+  screenshotPath?: any;
   // The padding that needs to be added to the toolbar bar on iOS and Android to do a proper cutout of the the viewport.
   toolBarShadowPadding?: number;
 

lib/methods/images.interfaces.ts

@@ -93,7 +93,7 @@ export interface ImageCompareFolderOptions {
   // The actual folder
   actualFolder: string;
   // The baseline folder
-  baselineFolder: string;
+  baselineFolder: any;
   // The name of the browser
   browserName: string;
   // The name of the device