null check.

Author: sergey-shandar

src/ResourceManager/Common/Commands.Common.Strategies/Extensions.cs

@@ -34,6 +34,10 @@ public static TValue GetOrNull<TKey, TValue>(
             this IDictionary<TKey, TValue> dictionary, TKey key)
             where TValue : class
         {
+            if (key == null)
+            {
+                return null;
+            }
             TValue result;
             dictionary.TryGetValue(key, out result);
             return result;

src/ResourceManager/Common/Commands.Common.Strategies/GetStateExtensions.cs

@@ -47,20 +47,20 @@ static async Task GetStateAsync<TModel>(
             this StateOperationContext context, ResourceConfig<TModel> config)
             where TModel : class
             => await context.GetOrAdd(
-                    config,
-                    async () =>
+                config,
+                async () =>
+                {
+                    var info = await config.GetAsync(context.Client, context.CancellationToken);
+                    // Get state of dependencies if the resource doesn't exist
+                    if (info == null)
                     {
-                        var info = await config.GetAsync(context.Client, context.CancellationToken);
-                        // Get state of dependencies if the resource doesn't exist
-                        if (info == null)
-                        {
-                            var tasks = config
-                                .GetResourceDependencies()
-                                .Select(context.GetStateAsyncDispatch);
-                            await Task.WhenAll(tasks);
-                        }
-                        return info;
-                    });
+                        var tasks = config
+                            .GetResourceDependencies()
+                            .Select(context.GetStateAsyncDispatch);
+                        await Task.WhenAll(tasks);
+                    }
+                    return info;
+                });
 
         sealed class GetStateAsyncVisitor : IResourceConfigVisitor<StateOperationContext, Task>
         {

src/ResourceManager/Common/Commands.Common.Strategies/State.cs

@@ -27,7 +27,7 @@ readonly ConcurrentDictionary<string, object> _Map
 
         public TModel Get<TModel>(ResourceConfig<TModel> config)
             where TModel : class
-            => _Map.GetOrNull(config.DefaultIdStr()) as TModel;
+            => _Map.GetOrNull(config?.DefaultIdStr()) as TModel;
 
         public TModel GetOrAdd<TModel>(ResourceConfig<TModel> config, Func<TModel> f)
             where TModel : class

src/ResourceManager/Compute/Commands.Compute/VirtualMachine/Operation/NewAzureVMCommand.cs

@@ -402,7 +402,7 @@ async Task StrategyExecuteCmdletAsync(IAsyncCmdlet asyncCmdlet)
 
             if (target.Get(availabilitySet) != null)
             {
-                throw new CloudException("Availability set doesn't exsist.");
+                throw new InvalidOperationException("Availability set doesn't exist.");
             }
 
             // apply target state