Browser tests: reduce timeout for instantiation to reasonable value

The timeout for browser instantiation in the browser tests has been
increased to avoid flaky tests. However, browser instantiation taking
that long is an indicator for something being wrong with the
instantiation. There is no reason why instantiation may take that long
during test execution but the same issue should never arise in
productive use, thus such a case should be captured by tests and, if
necessary, be fixed productively.

In order to do so, this change reduces the test timeout value again to a
more reasonable value. Since the first Edge browser instantiation takes
rather long at least in the GitHub actions test environment, that
instantiation is isolated in an execution before the test class.

Related to
#1676

Author: HeikoKlare

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_browser_Browser.java

@@ -102,16 +102,15 @@
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
 public class Test_org_eclipse_swt_browser_Browser extends Test_org_eclipse_swt_widgets_Composite {
 
-	// TODO Reduce to reasonable value
-	private static Duration MAXIMUM_BROWSER_CREATION_TIME = Duration.ofSeconds(90);
+	private static Duration MAXIMUM_BROWSER_CREATION_TIME = Duration.ofSeconds(10);
 
 	static {
 		try {
 			printSystemEnv();
 		} catch (Exception e) {
 			e.printStackTrace();
 		}
-		System.setProperty("org.eclipse.swt.internal.win32.Edge.timeout", Long.toString(MAXIMUM_BROWSER_CREATION_TIME.toMillis()));
+		System.setProperty("org.eclipse.swt.internal.win32.Edge.timeout", Long.toString(Duration.ofSeconds(90).toMillis()));
 	}
 
 	// CONFIG
@@ -165,10 +164,11 @@ public Test_org_eclipse_swt_browser_Browser(int swtBrowserSettings) {
 
 @BeforeClass
 public static void setupEdgeEnvironment() {
-	// initialize Edge environment before any test runs to isolate environment setup
+	// Initialize Edge environment before any test runs to isolate environment setup
+	// as this takes quite long in GitHub Actions builds
 	if (SwtTestUtil.isWindows) {
 		Shell shell = new Shell();
-		new Browser(shell, SWT.EDGE);
+		new Browser(shell, SWT.EDGE).getUrl();
 		shell.dispose();
 	}
 }
@@ -2846,7 +2846,12 @@ private static List<String> getOpenedDescriptors() {
 	try(DirectoryStream<Path> directoryStream = Files.newDirectoryStream(fd)){
 		directoryStream.forEach(f -> {
 			try {
-				paths.add(Files.isSymbolicLink(f)? Files.readSymbolicLink(f).toString() : f.toString());
+				// Do not consider file descriptors of Maven artifacts that are currently opened by other Maven
+				// plugins executed in parallel build (such as parallel compilation of the swt.tools bundle etc.)
+				String resolvedPath = Files.isSymbolicLink(f)? Files.readSymbolicLink(f).toString() : f.toString();
+				if (!resolvedPath.contains(".m2")) {
+					paths.add(resolvedPath);
+				}
 			} catch (IOException e) {
 				e.printStackTrace();
 			}

tests/org.eclipse.swt.tests/build.properties

@@ -23,3 +23,12 @@ bin.includes = .,\
                META-INF/
 
 bin.excludes = ManualTests/
+
+# The following dependency prevents parallel build of this and other bundles. 
+# Browser tests highly depend on system state and thus become flaky when other bundles
+# are built in parallel. 
+additional.bundles = org.eclipse.swt.tools,\
+                     org.eclipse.swt.examples,\
+                     org.eclipse.swt.examples.browser.demos,\
+                     org.eclipse.swt.examples.launcher,\
+                     org.eclipse.swt.examples.views