feat: add TEST_SCREENSHOTS_SAVED event

Author: Nikolai Markov

README.md

@@ -534,6 +534,7 @@ Property name              | Description
 Event                     | Description
 ------------------------- | -------------
 `DATABASE_CREATED`        | Will be triggered after sqlite database is created. The handler accepts a database instance. The event is synchronous.
+`TEST_SCREENSHOTS_SAVED`       | Will be triggered after test screenshots were saved. The handler accepts test id and screenshots info. The event is synchronous.
 
 ### events
 
@@ -554,6 +555,29 @@ module.exports = (hermione, opts) => {
 };
 ```
 
+Example of a subscription to an event `TEST_SCREENSHOTS_SAVED`:
+
+```js
+hermione.htmlReporter.on(hermione.htmlReporter.events.TEST_SCREENSHOTS_SAVED, ({testId, attempt, imagesInfo}) => {
+    console.log(`Screenshots for test "${testId}" (attempt #${attempt}) were saved:`, imagesInfo);
+    /* Expected output:
+    Screenshots for test "Feature Test.chrome-desktop" (attempt #0) were saved:
+    [
+        {
+            stateName: 'plain',
+            refImg: { path: '...', size: { width: 400, height: 200 } },
+            status: 'fail',
+            error: undefined,
+            diffClusters: [...],
+            expectedImg: { path: '...', size: { width: 400, height: 200 } }
+            actualImg: { path: '...', size: { width: 400, height: 200 } }
+            diffImg: { path: '...', size: { width: 400, height: 200 } }
+        }
+    ]
+    */
+});
+```
+
 ### addExtraItem
 
 Adds item to html report as link:

lib/constants/plugin-events.js

@@ -1,7 +1,8 @@
 'use strict';
 
 const getSyncEvents = () => ({
-    DATABASE_CREATED: 'databaseCreated'
+    DATABASE_CREATED: 'databaseCreated',
+    TEST_SCREENSHOTS_SAVED: 'testScreenshotsSaved'
 });
 
 const events = getSyncEvents();

lib/test-adapter.js

@@ -330,8 +330,8 @@ module.exports = class TestAdapter {
         await fs.writeFile(detailsFilePath, detailsData);
     }
 
-    saveTestImages(reportPath, workers) {
-        return Promise.map(this.assertViewResults, async (assertResult) => {
+    async saveTestImages(reportPath, workers) {
+        const result = await Promise.map(this.assertViewResults, async (assertResult) => {
             const {stateName} = assertResult;
             const destRefPath = utils.getReferencePath(this, stateName);
             const srcRefPath = this.getRefImg(stateName).path;
@@ -363,6 +363,15 @@ module.exports = class TestAdapter {
 
             return Promise.all(actions);
         });
+
+        const htmlReporter = this._hermione.htmlReporter;
+        htmlReporter.emit(htmlReporter.events.TEST_SCREENSHOTS_SAVED, {
+            testId: this._testId,
+            attempt: this.attempt,
+            imagesInfo: this.getImagesInfo()
+        });
+
+        return result;
     }
 
     //parallelize and cache of 'gemini-core.Image.buildDiff' (because it is very slow)

test/unit/lib/test-adapter.js

@@ -29,7 +29,11 @@ describe('hermione test adapter', () => {
             stubConfig(config),
             {},
             {ImageDiffError, NoRefImageError},
-            Object.assign({imagesSaver: {saveImg: sandbox.stub()}}, htmlReporter)
+            Object.assign({
+                imagesSaver: {saveImg: sandbox.stub()},
+                events: {TEST_SCREENSHOTS_SAVED: 'testScreenshotsSaved'},
+                emit: sinon.stub()
+            }, htmlReporter)
         );
 
         return new HermioneTestResultAdapter(testResult, tool, pluginConfig, status);
@@ -291,6 +295,33 @@ describe('hermione test adapter', () => {
                 {destPath: 'diff/report/path', reportDir: 'html-report/path'}
             );
         });
+
+        it('should emit TEST_SCREENSHOTS_SAVED event', async () => {
+            tmp.tmpdir = 'tmp/dir';
+            const testResult = mkTestResult_({
+                id: () => '',
+                browserId: 'chrome',
+                assertViewResults: [err]
+            });
+            utils.getDiffPath.returns('diff/report/path');
+
+            const htmlReporterEmitStub = sinon.stub();
+            const hermioneTestAdapter = mkHermioneTestResultAdapter(testResult, {
+                htmlReporter: {
+                    emit: htmlReporterEmitStub
+                }
+            });
+            sinon.stub(hermioneTestAdapter, 'getImagesInfo').returns([{test: 123}]);
+            const workers = {saveDiffTo: sandbox.stub()};
+
+            await hermioneTestAdapter.saveTestImages('', workers);
+
+            assert.calledOnceWith(htmlReporterEmitStub, 'testScreenshotsSaved', {
+                attempt: 0,
+                testId: 'default-title.chrome',
+                imagesInfo: [{test: 123}]
+            });
+        });
     });
 
     describe('hasDiff()', () => {