Fixed the WorkflowExecutor and DoTaskExecutor to ignore the flow directive of skipped tasks

src/runner/Synapse.Runner/Extensions/WorkflowDefinitionExtensions.cs

@@ -28,7 +28,7 @@ public static class WorkflowDefinitionExtensions
     public static MapEntry<string, TaskDefinition>? GetTaskAfter(this WorkflowDefinition workflow, TaskInstance after)
     {
         ArgumentNullException.ThrowIfNull(after);
-        switch (after.Next)
+        switch (after.Status == TaskInstanceStatus.Skipped ? FlowDirective.Continue : after.Next)
         {
             case FlowDirective.Continue:
                 var afterTask = workflow.Do[after.Name!];

src/runner/Synapse.Runner/Services/Executors/DoTaskExecutor.cs

@@ -98,20 +98,19 @@ protected virtual async Task OnSubTaskFaultAsync(ITaskExecutor executor, Cancell
     /// <returns>A new awaitable <see cref="Task"/></returns>
     protected virtual async Task OnSubtaskCompletedAsync(ITaskExecutor executor, CancellationToken cancellationToken)
     {
-        ArgumentNullException.ThrowIfNull(executor);
         var last = executor.Task.Instance;
         var output = executor.Task.Output!;
         var nextDefinition = this.Task.Definition.Do.GetTaskAfter(last);
         this.Executors.Remove(executor);
         if (this.Task.ContextData != executor.Task.ContextData) await this.Task.SetContextDataAsync(executor.Task.ContextData, cancellationToken).ConfigureAwait(false);
         if (nextDefinition == null || nextDefinition.Value == null)
         {
-            await this.SetResultAsync(output, last.Next == FlowDirective.End ? FlowDirective.End : this.Task.Definition.Then, cancellationToken).ConfigureAwait(false);
+            await this.SetResultAsync(output, last.Status != TaskInstanceStatus.Skipped && last.Next == FlowDirective.End ? FlowDirective.End : this.Task.Definition.Then, cancellationToken).ConfigureAwait(false);
             return;
         }
         var nextDefinitionIndex = this.Task.Definition.Do.Keys.ToList().IndexOf(nextDefinition.Key);
         TaskInstance next;
-        switch (executor.Task.Instance.Next)
+        switch (executor.Task.Instance.Status == TaskInstanceStatus.Skipped ? FlowDirective.Continue : executor.Task.Instance.Next)
         {
             case FlowDirective.End:
                 await this.SetResultAsync(output, FlowDirective.End, cancellationToken).ConfigureAwait(false);

src/runner/Synapse.Runner/Services/Executors/OpenApiCallExecutor.cs

@@ -109,14 +109,16 @@ protected override async Task DoInitializeAsync(CancellationToken cancellationTo
         this.OpenApi = (OpenApiCallDefinition)this.JsonSerializer.Convert(this.Task.Definition.With, typeof(OpenApiCallDefinition))!;
         using var httpClient = this.HttpClientFactory.CreateClient();
         await httpClient.ConfigureAuthenticationAsync(this.Task.Workflow.Definition, this.OpenApi.Document.Endpoint.Authentication, this.ServiceProvider, cancellationToken).ConfigureAwait(false);
-        var uri = StringFormatter.NamedFormat(this.OpenApi.Document.EndpointUri.OriginalString, this.Task.Input.ToDictionary());
-        if (uri.IsRuntimeExpression()) uri = await this.Task.Workflow.Expressions.EvaluateAsync<string>(uri, this.Task.Input, this.GetExpressionEvaluationArguments(), cancellationToken).ConfigureAwait(false);
-        using var request = new HttpRequestMessage(HttpMethod.Get, uri);
+        var uriString = StringFormatter.NamedFormat(this.OpenApi.Document.EndpointUri.OriginalString, this.Task.Input.ToDictionary());
+        if (uriString.IsRuntimeExpression()) uriString = await this.Task.Workflow.Expressions.EvaluateAsync<string>(uriString, this.Task.Input, this.GetExpressionEvaluationArguments(), cancellationToken).ConfigureAwait(false);
+        if (string.IsNullOrWhiteSpace(uriString)) throw new NullReferenceException("The OpenAPI endpoint URI cannot be null or whitespace");
+        if (!Uri.TryCreate(uriString, UriKind.RelativeOrAbsolute, out var uri) || uri == null) throw new Exception($"Failed to parse the specified string '{uriString}' into a new URI");
+        using var request = new HttpRequestMessage(HttpMethod.Get, uriString);
         using var response = await httpClient.SendAsync(request, cancellationToken).ConfigureAwait(false);
         if (!response.IsSuccessStatusCode)
         {
             var responseContent = await response.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
-            this.Logger.LogInformation("Failed to retrieve the OpenAPI document at location '{uri}'. The remote server responded with a non-success status code '{statusCode}'.", this.OpenApi.Document.EndpointUri, response.StatusCode);
+            this.Logger.LogInformation("Failed to retrieve the OpenAPI document at location '{uri}'. The remote server responded with a non-success status code '{statusCode}'.", uri, response.StatusCode);
             this.Logger.LogDebug("Response content:\r\n{responseContent}", responseContent ?? "None");
             response.EnsureSuccessStatusCode();
         }
@@ -125,11 +127,11 @@ protected override async Task DoInitializeAsync(CancellationToken cancellationTo
         var operation = this.Document.Paths
             .SelectMany(p => p.Value.Operations)
             .FirstOrDefault(o => o.Value.OperationId == this.OpenApi.OperationId);
-        if (operation.Value == null) throw new NullReferenceException($"Failed to find an operation with id '{this.OpenApi.OperationId}' in OpenAPI document at '{this.OpenApi.Document.EndpointUri}'");
+        if (operation.Value == null) throw new NullReferenceException($"Failed to find an operation with id '{this.OpenApi.OperationId}' in OpenAPI document at '{uri}'");
         this.HttpMethod = operation.Key.ToHttpMethod();
         this.Operation = operation.Value;
         this.Servers = this.Document.Servers.Select(s => s.Url).ToList();
-        if (this.Servers.Count == 0) this.Servers.Add(this.OpenApi.Document.EndpointUri.OriginalString.Replace(this.OpenApi.Document.EndpointUri.PathAndQuery, string.Empty));
+        if (this.Servers.Count == 0) this.Servers.Add(uri.OriginalString.Replace(uri.PathAndQuery, string.Empty));
         var path = this.Document.Paths.Single(p => p.Value.Operations.Any(o => o.Value.OperationId == operation.Value.OperationId));
         this.Path = path.Key;
         await this.BuildParametersAsync(cancellationToken).ConfigureAwait(false);

src/runner/Synapse.Runner/Services/WorkflowExecutor.cs

@@ -265,7 +265,7 @@ protected virtual async Task OnTaskFaultedAsync(ITaskExecutor executor, Cancella
     /// <returns>A new awaitable <see cref="Task"/></returns>
     protected virtual async Task OnTaskCompletedAsync(ITaskExecutor executor, CancellationToken cancellationToken)
     {
-        var nextDefinition = executor.Task.Instance.Next switch
+        var nextDefinition = (executor.Task.Instance.Status == TaskInstanceStatus.Skipped ? FlowDirective.Continue : executor.Task.Instance.Next) switch
         {
             FlowDirective.End or FlowDirective.Exit => null,
             _ => this.Workflow.Definition.GetTaskAfter(executor.Task.Instance)