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Merged
danielgerlag merged 4 commits into from
Aug 19, 2026
Merged

Add .NET 10 support: fix InvalidProgramException in expression compilation #1429

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4d60ab4
Add .NET 10 support: fix InvalidProgramException in expression compil…
danielgerlag May 16, 2026
56206b8
Add regression test for scalar inputs (issue #1428)
danielgerlag Jul 15, 2026
9d2d787
Merge remote-tracking branch 'origin/master' into fix/net10-expressio…
danielgerlag Jul 15, 2026
3299426
ci: install .NET 10 SDK in Azure-Tests job
danielgerlag Jul 15, 2026
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2 changes: 2 additions & 0 deletions .github/workflows/dotnet.yml
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Expand Up @@ -303,8 +303,10 @@ jobs:
uses: actions/setup-dotnet@v1
with:
dotnet-version: |
6.0.x
8.0.x
9.0.x
10.0.x
- name: Restore dependencies
run: dotnet restore
- name: Build
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55 changes: 48 additions & 7 deletions src/WorkflowCore.DSL/Services/DefinitionLoader.cs
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Expand Up @@ -318,12 +318,14 @@ private void AttachDirectlyOutput(KeyValuePair<string, string> output, WorkflowS
propertyInfo = dataType.GetProperty("Item");
targetProperty = Expression.Property(dataParameter, propertyInfo, Expression.Constant(output.Key));

var compiledSourceExpr = sourceExpr.Compile();

Action<IStepBody, object> acn = (pStep, pData) =>
{
object resolvedValue;
try
{
resolvedValue = sourceExpr.Compile().DynamicInvoke(pStep);
resolvedValue = compiledSourceExpr.DynamicInvoke(pStep);
}
catch (TargetInvocationException ex)
{
Expand Down Expand Up @@ -377,13 +379,16 @@ private void AttachNestedOutput(KeyValuePair<string, string> output, WorkflowSte
}
propertyInfo = ((PropertyInfo)memberExpression.Member).PropertyType.GetProperty("Item");

var targetExpr = Expression.Lambda(memberExpression, dataParameter);
var compiledTargetExpr = targetExpr.Compile();
var compiledSourceExpr = sourceExpr.Compile();

Action<IStepBody, object> acn = (pStep, pData) =>
{
var targetExpr = Expression.Lambda(memberExpression, dataParameter);
object data;
try
{
data = targetExpr.Compile().DynamicInvoke(pData);
data = compiledTargetExpr.DynamicInvoke(pData);
}
catch (TargetInvocationException ex)
{
Expand All @@ -392,7 +397,7 @@ private void AttachNestedOutput(KeyValuePair<string, string> output, WorkflowSte
object resolvedValue;
try
{
resolvedValue = sourceExpr.Compile().DynamicInvoke(pStep);
resolvedValue = compiledSourceExpr.DynamicInvoke(pStep);
}
catch (TargetInvocationException ex)
{
Expand Down Expand Up @@ -470,12 +475,14 @@ private static Action<IStepBody, object, IStepExecutionContext> BuildScalarInput
throw new WorkflowDefinitionLoadException($"Error parsing input expression '{expr}' for property '{input.Key}': {ex.Message}", ex);
}

var compiledExpr = sourceExpr.Compile();

void acn(IStepBody pStep, object pData, IStepExecutionContext pContext)
{
object resolvedValue;
try
{
resolvedValue = sourceExpr.Compile().DynamicInvoke(pData, pContext, Environment.GetEnvironmentVariables());
resolvedValue = compiledExpr.DynamicInvoke(pData, pContext, Environment.GetEnvironmentVariables());
}
catch (TargetInvocationException ex)
{
Expand Down Expand Up @@ -505,6 +512,40 @@ void acn(IStepBody pStep, object pData, IStepExecutionContext pContext)

private static Action<IStepBody, object, IStepExecutionContext> BuildObjectInputAction(KeyValuePair<string, object> input, ParameterExpression dataParameter, ParameterExpression contextParameter, ParameterExpression environmentVarsParameter, PropertyInfo stepProperty)
{
// Pre-compile all @-prefixed property expressions at definition load time
var compiledExpressions = new Dictionary<string, Delegate>();
var templateObj = JObject.FromObject(input.Value);
var scanStack = new Stack<JObject>();
scanStack.Push(templateObj);

while (scanStack.Count > 0)
{
var subobj = scanStack.Pop();
foreach (var prop in subobj.Properties())
{
if (prop.Name.StartsWith("@"))
{
var exprText = prop.Value.ToString();
if (!compiledExpressions.ContainsKey(exprText))
{
LambdaExpression sourceExpr;
try
{
sourceExpr = DynamicExpressionParser.ParseLambda(ParsingConfig, false, new[] { dataParameter, contextParameter, environmentVarsParameter }, typeof(object), TransformExpression(exprText));
}
catch (Exception ex) when (ex is System.Linq.Dynamic.Core.Exceptions.ParseException || ex is InvalidOperationException)
{
throw new WorkflowDefinitionLoadException($"Error parsing input expression '{exprText}': {ex.Message}", ex);
}
compiledExpressions[exprText] = sourceExpr.Compile();
}
}
}

foreach (var child in subobj.Children<JObject>())
scanStack.Push(child);
Comment on lines +545 to +546

@danielgerlag danielgerlag Jul 15, 2026

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Good catch, but this is intentional here: the pre-scan deliberately mirrors the exact same Children<JObject>() traversal the runtime acn uses below, so the pre-compiled compiledExpressions dictionary is guaranteed to contain a key for every @-property the runtime scan will later look up — no KeyNotFound risk. The nested-object limitation you spotted is pre-existing behavior on master (this PR only lifts the compile step out of the closure to fix the .NET 10 InvalidProgramException); making the template walk recurse into nested objects is a separate behavior change I would rather not fold into this fix.

}

void acn(IStepBody pStep, object pData, IStepExecutionContext pContext)
{
var stack = new Stack<JObject>();
Expand All @@ -518,11 +559,11 @@ void acn(IStepBody pStep, object pData, IStepExecutionContext pContext)
{
if (prop.Name.StartsWith("@"))
{
var sourceExpr = DynamicExpressionParser.ParseLambda(ParsingConfig, false, new[] { dataParameter, contextParameter, environmentVarsParameter }, typeof(object), TransformExpression(prop.Value.ToString()));
var exprText = prop.Value.ToString();
object resolvedValue;
try
Comment on lines 560 to 564

@danielgerlag danielgerlag Jul 15, 2026

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This Children<JObject>() line is unchanged from master — it is the existing runtime traversal, not something introduced by this PR. Scope here is limited to the .NET 10 compile fix, so I am keeping the traversal behavior identical. Happy to open a follow-up to properly recurse nested objects/array elements (in both the pre-scan and this loop together) if we want to support nested @ expressions.

{
resolvedValue = sourceExpr.Compile().DynamicInvoke(pData, pContext, Environment.GetEnvironmentVariables());
resolvedValue = compiledExpressions[exprText].DynamicInvoke(pData, pContext, Environment.GetEnvironmentVariables());
}
catch (TargetInvocationException ex)
{
Expand Down
20 changes: 11 additions & 9 deletions src/WorkflowCore/Models/MemberMapParameter.cs
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Expand Up @@ -9,6 +9,7 @@ public class MemberMapParameter : IStepParameter
{
private readonly LambdaExpression _source;
private readonly LambdaExpression _target;
private readonly Delegate _compiledSource;

public MemberMapParameter(LambdaExpression source, LambdaExpression target)
{
Expand All @@ -17,44 +18,45 @@ public MemberMapParameter(LambdaExpression source, LambdaExpression target)

_source = source;
_target = target;
_compiledSource = source.Compile();
}

private void Assign(object sourceObject, LambdaExpression sourceExpr, object targetObject, LambdaExpression targetExpr, IStepExecutionContext context)
private void Assign(object sourceObject, object targetObject, IStepExecutionContext context)
{
object resolvedValue = null;

switch (sourceExpr.Parameters.Count)
switch (_source.Parameters.Count)
{
case 1:
resolvedValue = sourceExpr.Compile().DynamicInvoke(sourceObject);
resolvedValue = _compiledSource.DynamicInvoke(sourceObject);
break;
case 2:
resolvedValue = sourceExpr.Compile().DynamicInvoke(sourceObject, context);
resolvedValue = _compiledSource.DynamicInvoke(sourceObject, context);
break;
default:
throw new ArgumentException();
}

if (resolvedValue == null)
{
var defaultAssign = Expression.Lambda(Expression.Assign(targetExpr.Body, Expression.Default(targetExpr.ReturnType)), targetExpr.Parameters.Single());
var defaultAssign = Expression.Lambda(Expression.Assign(_target.Body, Expression.Default(_target.ReturnType)), _target.Parameters.Single());
defaultAssign.Compile().DynamicInvoke(targetObject);
return;
}

var valueExpr = Expression.Convert(Expression.Constant(resolvedValue), targetExpr.ReturnType);
var assign = Expression.Lambda(Expression.Assign(targetExpr.Body, valueExpr), targetExpr.Parameters.Single());
var valueExpr = Expression.Convert(Expression.Constant(resolvedValue), _target.ReturnType);
var assign = Expression.Lambda(Expression.Assign(_target.Body, valueExpr), _target.Parameters.Single());
assign.Compile().DynamicInvoke(targetObject);
}

public void AssignInput(object data, IStepBody body, IStepExecutionContext context)
{
Assign(data, _source, body, _target, context);
Assign(data, body, context);
}

public void AssignOutput(object data, IStepBody body, IStepExecutionContext context)
{
Assign(body, _source, data, _target, context);
Assign(body, data, context);
}
}
}
2 changes: 1 addition & 1 deletion test/Directory.Build.props
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@@ -1,6 +1,6 @@
<Project>
<PropertyGroup>
<TargetFrameworks>net6.0;net8.0</TargetFrameworks>
<TargetFrameworks>net6.0;net8.0;net10.0</TargetFrameworks>
<LangVersion>latest</LangVersion>
<IsPackable>false</IsPackable>
<IsTestProject>true</IsTestProject>
Expand Down
2 changes: 1 addition & 1 deletion test/WorkflowCore.IntegrationTests/WorkflowCore.IntegrationTests.csproj
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Expand Up @@ -7,7 +7,7 @@
<GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
<GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
<GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
<TargetFrameworks>net6.0</TargetFrameworks>
<TargetFrameworks>net6.0;net8.0;net10.0</TargetFrameworks>
</PropertyGroup>

<ItemGroup>
Expand Down
7 changes: 7 additions & 0 deletions test/WorkflowCore.TestAssets/DataTypes/ScalarInputData.cs
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@@ -0,0 +1,7 @@
namespace WorkflowCore.TestAssets.DataTypes
{
public class ScalarInputData
{
public string MessageId { get; set; }
}
}
17 changes: 17 additions & 0 deletions test/WorkflowCore.TestAssets/Steps/ScalarInputStep.cs
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@@ -0,0 +1,17 @@
using WorkflowCore.Interface;
using WorkflowCore.Models;

namespace WorkflowCore.TestAssets.Steps
{
public class ScalarInputStep : StepBody
{
public string MessageId { get; set; }

public string Status { get; set; }

public override ExecutionResult Run(IStepExecutionContext context)
{
return ExecutionResult.Next();
}
}
}
43 changes: 43 additions & 0 deletions test/WorkflowCore.UnitTests/Services/DefinitionStorage/DefinitionLoaderTests.cs
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@@ -1,11 +1,13 @@
using FakeItEasy;
using FluentAssertions;
using Newtonsoft.Json;
using System;
using System.Linq;
using WorkflowCore.Interface;
using WorkflowCore.Models;
using WorkflowCore.Services.DefinitionStorage;
using WorkflowCore.TestAssets.DataTypes;
using WorkflowCore.TestAssets.Steps;
using Xunit;

namespace WorkflowCore.UnitTests.Services.DefinitionStorage
Expand Down Expand Up @@ -71,6 +73,47 @@ public void ParseDefinitionInputException()
Assert.Throws<ArgumentException>(() => _subject.LoadDefinition(TestAssets.Utils.GetTestDefinitionJsonMissingInputProperty(), Deserializers.Json));
}

// Regression test for issue #1428: a scalar variable-binding input plus a
// scalar string-literal input. The compiled input expressions used to be
// built inside a closure and recompiled on every invocation, which produced
// an InvalidProgramException on .NET 10. Loading the definition and then
// assigning the inputs (as WorkflowExecutor.ExecuteStep does) must succeed
// and resolve both values.
[Fact(DisplayName = "Should evaluate scalar variable and string-literal inputs")]
public void ParseAndAssignScalarInputs()
{
var dataType = typeof(ScalarInputData).AssemblyQualifiedName;
var stepType = typeof(ScalarInputStep).AssemblyQualifiedName;

var json =
"{" +
"\"Id\": \"Issue1428\", \"Version\": 1," +
"\"DataType\": " + JsonConvert.ToString(dataType) + "," +
"\"Steps\": [{" +
"\"Id\": \"UpdateStatus\"," +
"\"Name\": \"Update internal status\"," +
"\"StepType\": " + JsonConvert.ToString(stepType) + "," +
"\"Inputs\": {" +
"\"MessageId\": \"data.MessageId\"," +
"\"Status\": \"\\\"waits-for-batching\\\"\"" +
"}" +
"}]}";

var def = _subject.LoadDefinition(json, Deserializers.Json);

var step = def.Steps.Single(s => s.ExternalId == "UpdateStatus");
step.Inputs.Count.Should().Be(2);

var body = new ScalarInputStep();
var data = new ScalarInputData { MessageId = "msg-42" };

foreach (var input in step.Inputs)
input.AssignInput(data, body, null);

body.MessageId.Should().Be("msg-42");
body.Status.Should().Be("waits-for-batching");
}

private bool MatchTestDefinition(WorkflowDefinition def)
{
//TODO: make this better
Expand Down
2 changes: 1 addition & 1 deletion test/WorkflowCore.UnitTests/WorkflowCore.UnitTests.csproj
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Expand Up @@ -7,7 +7,7 @@
<GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
<GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
<GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
<TargetFrameworks>net6.0</TargetFrameworks>
<TargetFrameworks>net6.0;net8.0;net10.0</TargetFrameworks>
</PropertyGroup>

<ItemGroup>
Expand Down
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