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Fix duplicate client/operation names when operation IDs contain multiple underscores #5348

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Merged
lahma merged 2 commits into from
Mar 6, 2026
+64 −29
Merged

Fix duplicate client/operation names when operation IDs contain multiple underscores #5348

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Copilot Mar 6, 2026
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Fix duplicate class/method generation when operation IDs contain mult…
Copilot Mar 6, 2026
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62 changes: 58 additions & 4 deletions src/NSwag.CodeGeneration.Tests/CodeGenerationTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -84,8 +84,8 @@ public void When_using_MultipleClientsFromFirstTagAndOperationName_then_ensure_t
}

[Theory(DisplayName = "Ensure expected operation name generation when using MultipleClientsFromFirstTagAndOperationName behavior")]
[InlineData("OperationId_SecondUnderscore_Test", "Test")]
[InlineData("OperationId_MultipleUnderscores_Client_Test", "Test")]
[InlineData("OperationId_SecondUnderscore_Test", "SecondUnderscore_Test")]
[InlineData("OperationId_MultipleUnderscores_Client_Test", "MultipleUnderscores_Client_Test")]
[InlineData("OperationId_Test", "Test")]
[InlineData("UnderscoreLast_", "UnderscoreLast_")]
[InlineData("_UnderscoreFirst", "UnderscoreFirst")]
Expand All @@ -111,8 +111,8 @@ public void When_using_MultipleClientsFromFirstTagAndOperationName_then_ensure_t
}

[Theory(DisplayName = "Ensure expected client name generation with different operationIds when using the MultipleClientsFromOperationId behavior")]
[InlineData("OperationId_SecondUnderscore_Test", "SecondUnderscore")]
[InlineData("OperationId_MultipleUnderscores_Client_Test", "Client")]
[InlineData("OperationId_SecondUnderscore_Test", "OperationId")]
[InlineData("OperationId_MultipleUnderscores_Client_Test", "OperationId")]
[InlineData("OperationId_Test", "OperationId")]
[InlineData("UnderscoreLast_", "UnderscoreLast")]
[InlineData("_UnderscoreFirst", "")]
Expand All @@ -139,5 +139,59 @@ public void When_using_MultipleClientsFromOperationId_then_ensure_that_underscor
// Assert
Assert.Equal(expectedClientName, clientName);
}

[Theory(DisplayName = "Ensure expected operation name generation with different operationIds when using the MultipleClientsFromOperationId behavior")]
[InlineData("OperationId_SecondUnderscore_Test", "SecondUnderscore_Test")]
[InlineData("OperationId_MultipleUnderscores_Client_Test", "MultipleUnderscores_Client_Test")]
[InlineData("OperationId_Test", "Test")]
[InlineData("UnderscoreLast_", "UnderscoreLast_")]
[InlineData("_UnderscoreFirst", "UnderscoreFirst")]
[InlineData("NoUnderscore", "NoUnderscore")]
public void When_using_MultipleClientsFromOperationId_then_ensure_that_operationname_is_correct(string operationId, string expectedOperationName)
{
// Arrange
var operation = new OpenApiOperation
{
OperationId = operationId
};
var generator = new MultipleClientsFromOperationIdOperationNameGenerator();

var document = new OpenApiDocument();
var path = string.Empty;
var httpMethod = string.Empty;

// Act
string operationName = generator.GetOperationName(document, path, httpMethod, operation);

// Assert
Assert.Equal(expectedOperationName, operationName);
}

[Theory(DisplayName = "Ensure unique (client, operation) pairs when using MultipleClientsFromOperationId to avoid duplicate method names")]
[InlineData("Orders_items_get", "Products_items_get")]
[InlineData("Resource1_getSomething", "Resource2_getSomething")]
[InlineData("A_B_C", "D_B_C")]
public void When_using_MultipleClientsFromOperationId_then_unique_operationIds_produce_unique_client_operation_pairs(string operationId1, string operationId2)
{
// Arrange
var operation1 = new OpenApiOperation { OperationId = operationId1 };
var operation2 = new OpenApiOperation { OperationId = operationId2 };
var generator = new MultipleClientsFromOperationIdOperationNameGenerator();

var document = new OpenApiDocument();
var path = string.Empty;
var httpMethod = string.Empty;

// Act
string clientName1 = generator.GetClientName(document, path, httpMethod, operation1);
string operationName1 = generator.GetOperationName(document, path, httpMethod, operation1);
string clientName2 = generator.GetClientName(document, path, httpMethod, operation2);
string operationName2 = generator.GetOperationName(document, path, httpMethod, operation2);

// Assert: unique operation IDs must not produce the same (client, operation) pair
Assert.False(
clientName1 == clientName2 && operationName1 == operationName2,
$"OperationIds '{operationId1}' and '{operationId2}' produced duplicate (client='{clientName1}', operation='{operationName1}') pair");
}
}
}
31 changes: 6 additions & 25 deletions ...eneration/OperationNameGenerators/MultipleClientsFromOperationIdOperationNameGenerator.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -81,42 +81,23 @@ public virtual string GetOperationName(OpenApiDocument document, string path, st
private static ReadOnlySpan<char> GetClientName(OpenApiOperation operation)
{
ReadOnlySpan<char> operationIdSpan = operation.OperationId.AsSpan();
const char underscoreSeparator = '_';
int idxFirst = operationIdSpan.IndexOf(underscoreSeparator);
int idx = operationIdSpan.IndexOf('_');

// no underscore, fast path
if (idxFirst == -1)
// no underscore or underscore is the first character
if (idx <= 0)
{
return [];
}

int idxLast = operationIdSpan.LastIndexOf(underscoreSeparator);

// only one underscore
if (idxFirst == idxLast)
{
// underscore is the first character
if (idxFirst == 0)
{
return [];
}

return operationIdSpan.Slice(0, idxFirst);
}

// backwards search for the second underscore
// e.g. OperationId_SecondUnderscore_Test => SecondUnderscore
operationIdSpan = operationIdSpan.Slice(0, idxLast);
int idxSecondLast = operationIdSpan.LastIndexOf(underscoreSeparator);

return operationIdSpan.Slice(idxSecondLast + 1);
return operationIdSpan.Slice(0, idx);
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static ReadOnlySpan<char> GetOperationName(OpenApiOperation operation)
{
var span = operation.OperationId.AsSpan();
var idx = span.LastIndexOf('_');
var idx = span.IndexOf('_');
// No underscore, or underscore is the last character: return the full operation ID
return idx != -1 && idx < span.Length - 1
? span.Slice(idx + 1)
: span;
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