[CQ] stop blocking on FlutterPluginsLibraryManager update (flutter#8094)

See: flutter#8089

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Author: pq

flutter-idea/src/io/flutter/pub/PubRoots.java

@@ -48,7 +48,7 @@ public static List<PubRoot> forModule(@NotNull Module module) {
    * (Based on the filesystem cache; doesn't refresh anything.)
    */
   @NotNull
-  public static List<PubRoot> forProject(@NotNull Project project) {
+  public static List<@NotNull PubRoot> forProject(@NotNull Project project) {
     final List<PubRoot> result = new ArrayList<>();
     if (project.isDisposed()) return result;
 

flutter-idea/src/io/flutter/sdk/FlutterPluginsLibraryManager.java

@@ -7,13 +7,16 @@
 
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.ModalityState;
+import com.intellij.openapi.application.ReadAction;
 import com.intellij.openapi.project.DumbService;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.roots.ModuleRootEvent;
 import com.intellij.openapi.roots.ModuleRootListener;
 import com.intellij.openapi.roots.libraries.PersistentLibraryKind;
 import com.intellij.openapi.vfs.*;
+import com.intellij.util.concurrency.AppExecutorUtil;
 import com.jetbrains.lang.dart.util.DotPackagesFileUtil;
+import io.flutter.dart.FlutterDartAnalysisServer;
 import io.flutter.pub.PubRoot;
 import io.flutter.pub.PubRoots;
 import org.jetbrains.annotations.NotNull;
@@ -97,7 +100,7 @@ private void scheduleUpdate() {
     }
 
     final Runnable runnable = this::updateFlutterPlugins;
-    DumbService.getInstance(getProject()).smartInvokeLater(runnable, ModalityState.NON_MODAL);
+    DumbService.getInstance(getProject()).smartInvokeLater(runnable, ModalityState.nonModal());
   }
 
   private void updateFlutterPlugins() {
@@ -114,15 +117,22 @@ private void updateFlutterPlugins() {
   }
 
   private void updateFlutterPluginsImpl() {
-    final Set<String> flutterPluginPaths = getFlutterPluginPaths(PubRoots.forProject(getProject()));
-    final Set<String> flutterPluginUrls = new HashSet<>();
-    for (String path : flutterPluginPaths) {
-      flutterPluginUrls.add(VfsUtilCore.pathToUrl(path));
-    }
-    updateLibraryContent(flutterPluginUrls);
+    Project project = getProject();
+
+    ReadAction.nonBlocking(() -> getFlutterPluginPaths(PubRoots.forProject(project)))
+      .expireWith(FlutterDartAnalysisServer.getInstance(project))
+      .finishOnUiThread(ModalityState.nonModal(), flutterPluginPaths -> {
+        if (flutterPluginPaths == null) return;
+        final Set<String> flutterPluginUrls = new HashSet<>();
+        for (String path : flutterPluginPaths) {
+          flutterPluginUrls.add(VfsUtilCore.pathToUrl(path));
+        }
+        updateLibraryContent(flutterPluginUrls);
+      })
+      .submit(AppExecutorUtil.getAppExecutorService());
   }
 
-  private static Set<String> getFlutterPluginPaths(List<PubRoot> roots) {
+  private static @NotNull Set<@NotNull String> getFlutterPluginPaths(@NotNull List<@NotNull PubRoot> roots) {
     final Set<String> paths = new HashSet<>();
 
     for (PubRoot pubRoot : roots) {
@@ -132,6 +142,7 @@ private static Set<String> getFlutterPluginPaths(List<PubRoot> roots) {
       }
 
       for (String packagePath : packagesMap.values()) {
+        if (packagePath == null) continue;;
         final VirtualFile libFolder = LocalFileSystem.getInstance().findFileByPath(packagePath);
         if (libFolder == null) {
           continue;