E2E tests: mention users in Slack based on report name and branch name (

#20964)

* Mention users in Slack based on configured report names and branch names

* Config updates of Slack handles

* Error handling - send notification event is mentions handling fails

projects/plugins/jetpack/changelog/e2e-slack-mention-atomic-runs

@@ -0,0 +1,4 @@
+Significance: patch
+Type: enhancement
+
+E2E tests: support user mentions in Slack based on report name and branch name

projects/plugins/jetpack/tests/e2e/bin/slack.js

@@ -326,26 +326,41 @@ function buildDefaultMessage( isSuccess, forceHeaderText = undefined ) {
 		},
 	];
 
-	if ( ! gh.pr && ! isSuccess && gh.branch.name === config.get( 'repository.mainBranch' ) ) {
-		const mentions = config
-			.get( 'slack.mentions' )
-			.map( function ( userId ) {
-				return ` <@${ userId }>`;
-			} )
-			.join( ' ' );
-
-		blocks.push(
-			{
-				type: 'section',
-				text: {
-					type: 'mrkdwn',
-					text: `cc ${ mentions }`,
-				},
-			},
-			{
-				type: 'divider',
+	// mention interested parties
+	try {
+		let handles = [];
+
+		for ( const branchEntry of config.get( 'slack.mentions.branches' ) ) {
+			if ( gh.branch.name === branchEntry.name ) {
+				handles = handles.concat( branchEntry.users );
 			}
-		);
+		}
+
+		for ( const reportEntry of config.get( 'slack.mentions.reports' ) ) {
+			if ( yargs.argv.report === reportEntry.name ) {
+				handles = handles.concat( reportEntry.users );
+			}
+		}
+
+		if ( handles.length > 0 && ! isSuccess ) {
+			// Create a single string of unique Slack handles
+			const mentions = [ ...new Set( handles ) ].join( ' ' );
+
+			blocks.push(
+				{
+					type: 'section',
+					text: {
+						type: 'mrkdwn',
+						text: `cc ${ mentions }`,
+					},
+				},
+				{
+					type: 'divider',
+				}
+			);
+		}
+	} catch ( error ) {
+		console.log( `ERROR: ${ error }` );
 	}
 
 	return blocks;