Features/webp support for splashscreen (#1113)

* - linting
- platform independent paths in testing
- addes some unittest
- remove duplication + add comments
- delete webp's if png's added, delete png's if webp' added.
- Update bin/templates/cordova/lib/prepare.js Co-authored-by: エリス <erisu@users.noreply.github.com>
- fix https://github.com/apache/cordova-plugin-splashscreen/issues/257 webp support for android

* revert changes

* refactor: use source extension for target in getImageResourcePath

* fix(prepare): include more extensions in initial splash-screen resource map

* tests(prepare): quick-fix for tests

* backward slashes must be changed to forward slashes for fast-glob package.

Co-authored-by: Raphael von der Grün <raphinesse@gmail.com>

spec/unit/prepare.spec.js

@@ -81,6 +81,18 @@ function mockGetIconItem (data) {
     }, data);
 }
 
+/**
+ * Create a mock item from the getSplashScreen collection with the supplied updated data.
+ *
+ * @param {Object} data Changes to apply to the mock getSplashScreen item
+ */
+function mockGetSplashScreenItem (data) {
+    return Object.assign({}, {
+        src: undefined,
+        density: undefined
+    }, data);
+}
+
 describe('prepare', () => {
     describe('updateIcons method', function () {
     // Rewire
@@ -833,4 +845,129 @@ describe('prepare', () => {
             ).toBeResolved();
         });
     });
+
+    describe('updateSplashes method', function () {
+        // Rewire
+        let prepare;
+
+        // Spies
+        let emitSpy;
+        let updatePathsSpy;
+
+        // Mock Data
+        let cordovaProject;
+        let platformResourcesDir;
+
+        beforeEach(function () {
+            prepare = rewire('../../bin/templates/cordova/lib/prepare');
+
+            cordovaProject = {
+                root: '/mock',
+                projectConfig: {
+                    path: '/mock/config.xml',
+                    cdvNamespacePrefix: 'cdv'
+                },
+                locations: {
+                    plugins: '/mock/plugins',
+                    www: '/mock/www'
+                }
+            };
+            platformResourcesDir = PATH_RESOURCE;
+
+            emitSpy = jasmine.createSpy('emit');
+            prepare.__set__('events', {
+                emit: emitSpy
+            });
+
+            updatePathsSpy = jasmine.createSpy('updatePaths');
+            prepare.__set__('FileUpdater', {
+                updatePaths: updatePathsSpy
+            });
+
+            // mocking initial responses for mapImageResources
+            prepare.__set__('makeSplashCleanupMap', (rootDir, resourcesDir) => ({
+                [path.join(resourcesDir, 'drawable-mdpi/screen.png')]: null,
+                [path.join(resourcesDir, 'drawable-mdpi/screen.webp')]: null
+            }));
+        });
+
+        it('Test#001 : Should detect no defined splash screens.', function () {
+            const updateSplashes = prepare.__get__('updateSplashes');
+
+            // mock data.
+            cordovaProject.projectConfig.getSplashScreens = function (platform) {
+                return [];
+            };
+
+            updateSplashes(cordovaProject, platformResourcesDir);
+
+            // The emit was called
+            expect(emitSpy).toHaveBeenCalled();
+
+            // The emit message was.
+            const actual = emitSpy.calls.argsFor(0)[1];
+            const expected = 'This app does not have splash screens defined';
+            expect(actual).toEqual(expected);
+        });
+
+        it('Test#02 : Should update splash png icon.', function () {
+            const updateSplashes = prepare.__get__('updateSplashes');
+
+            // mock data.
+            cordovaProject.projectConfig.getSplashScreens = function (platform) {
+                return [mockGetSplashScreenItem({
+                    density: 'mdpi',
+                    src: 'res/splash/android/mdpi-screen.png'
+                })];
+            };
+
+            updateSplashes(cordovaProject, platformResourcesDir);
+
+            // The emit was called
+            expect(emitSpy).toHaveBeenCalled();
+
+            // The emit message was.
+            const actual = emitSpy.calls.argsFor(0)[1];
+            const expected = 'Updating splash screens at ' + PATH_RESOURCE;
+            expect(actual).toEqual(expected);
+
+            const actualResourceMap = updatePathsSpy.calls.argsFor(0)[0];
+            const expectedResourceMap = {};
+            expectedResourceMap[path.join(PATH_RESOURCE, 'drawable-mdpi', 'screen.png')] = 'res/splash/android/mdpi-screen.png';
+            expectedResourceMap[path.join(PATH_RESOURCE, 'drawable-mdpi', 'screen.webp')] = null;
+
+            expect(actualResourceMap).toEqual(expectedResourceMap);
+        });
+
+        it('Test#03 : Should update splash webp icon.', function () {
+            const updateSplashes = prepare.__get__('updateSplashes');
+
+            // mock data.
+            cordovaProject.projectConfig.getSplashScreens = function (platform) {
+                return [mockGetSplashScreenItem({
+                    density: 'mdpi',
+                    src: 'res/splash/android/mdpi-screen.webp'
+                })];
+            };
+
+            // Creating Spies
+            updateSplashes(cordovaProject, platformResourcesDir);
+
+            // The emit was called
+            expect(emitSpy).toHaveBeenCalled();
+
+            // The emit message was.
+            const actual = emitSpy.calls.argsFor(0)[1];
+            const expected = 'Updating splash screens at ' + PATH_RESOURCE;
+            expect(actual).toEqual(expected);
+
+            const actualResourceMap = updatePathsSpy.calls.argsFor(0)[0];
+
+            const expectedResourceMap = {};
+            expectedResourceMap[path.join(PATH_RESOURCE, 'drawable-mdpi', 'screen.webp')] = 'res/splash/android/mdpi-screen.webp';
+            expectedResourceMap[path.join(PATH_RESOURCE, 'drawable-mdpi', 'screen.png')] = null;
+
+            expect(actualResourceMap).toEqual(expectedResourceMap);
+        });
+    });
 });