fix(Runner): Fixed the SwitchTaskExecutor to not throw when multiple cases match, and to select the first matching case, if any

Signed-off-by: Charles d'Avernas <[email protected]>

Author: cdavernas

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

@@ -32,14 +32,15 @@ public class SwitchTaskExecutor(IServiceProvider serviceProvider, ILogger<Switch
     /// <inheritdoc/>
     protected override async Task DoExecuteAsync(CancellationToken cancellationToken)
     {
-        var matches = new List<MapEntry<string, SwitchCaseDefinition>>();
+        MapEntry<string, SwitchCaseDefinition>? match = null;
         var defaultCase = this.Task.Definition.Switch.FirstOrDefault(kvp => string.IsNullOrWhiteSpace(kvp.Value.When));
         foreach (var @case in this.Task.Definition.Switch!.Where(c => !string.IsNullOrWhiteSpace(c.Value.When)))
         {
-            if (await this.Task.Workflow.Expressions.EvaluateConditionAsync(@case.Value.When!, this.Task.Input, this.GetExpressionEvaluationArguments(), cancellationToken).ConfigureAwait(false)) matches.Add(@case);
+            if (!await this.Task.Workflow.Expressions.EvaluateConditionAsync(@case.Value.When!, this.Task.Input, this.GetExpressionEvaluationArguments(), cancellationToken).ConfigureAwait(false)) continue;
+            match = @case;
+            break;
         }
-        if (matches.Count == 1) await this.SetResultAsync(this.Task.Input, matches.First().Value.Then, cancellationToken).ConfigureAwait(false);
-        else if (matches.Count > 1) await this.SetErrorAsync(Error.Configuration(this.Task.Instance.Reference, $"At most one matching case is allowed, but cases {string.Join(", ", matches.Select(m => m.Key))} have been matched."), cancellationToken).ConfigureAwait(false);
+        if (match != null) await this.SetResultAsync(this.Task.Input, match.Value.Then, cancellationToken).ConfigureAwait(false);
         else if (defaultCase != null) await this.SetResultAsync(this.Task.Input, defaultCase.Value.Then, cancellationToken).ConfigureAwait(false);
         else await this.SetResultAsync(this.Task.Input, this.Task.Definition.Then, cancellationToken).ConfigureAwait(false);
     }