[groovy] fix EA-63038 and EA-67911

plugins/groovy/src/org/jetbrains/plugins/groovy/annotator/intentions/GroovyStaticImportMethodFix.java

@@ -81,7 +81,14 @@ public class GroovyStaticImportMethodFix extends Intention {
   }
 
   @Nullable
-  private static GrReferenceExpression getMethodExpression(GrMethodCall call) {
+  private GrReferenceExpression getMethodExpression() {
+    GrMethodCall methodCall = myMethodCall.getElement();
+    if (methodCall == null) return null;
+    return getMethodExpression(methodCall);
+  }
+
+  @Nullable
+  private static GrReferenceExpression getMethodExpression(@NotNull GrMethodCall call) {
     GrExpression result = call.getInvokedExpression();
     return result instanceof GrReferenceExpression ? (GrReferenceExpression)result : null;
   }
@@ -89,12 +96,13 @@ public class GroovyStaticImportMethodFix extends Intention {
   @Override
   public boolean isAvailable(@NotNull Project project, Editor editor, PsiFile file) {
     myCandidates = null;
-    return myMethodCall.getElement() != null &&
-           myMethodCall.getElement().isValid() &&
-           getMethodExpression(myMethodCall.getElement()) != null &&
-           getMethodExpression(myMethodCall.getElement()).getQualifierExpression() == null &&
-           file.getManager().isInProject(file) &&
-           !getCandidates().isEmpty();
+
+    if (!file.getManager().isInProject(file)) return false;
+
+    GrReferenceExpression invokedExpression = getMethodExpression();
+    if (invokedExpression == null || invokedExpression.getQualifierExpression() != null) return false;
+
+    return !getCandidates().isEmpty();
   }
 
   @NotNull
@@ -189,10 +197,13 @@ public class GroovyStaticImportMethodFix extends Intention {
     return true;
   }
 
+  @NotNull
   private List<PsiMethod> getCandidates() {
-    if (myCandidates == null) {
-      myCandidates = getMethodsToImport();
+    List<PsiMethod> result = myCandidates;
+    if (result == null) {
+      result = getMethodsToImport();
+      myCandidates = result;
     }
-    return myCandidates;
+    return result;
   }
 }