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Coverage for "await foreach" loops and compiler-generated async iterators (issue #1104) (#1107)
Coverage for "await foreach" loops and compiler-generated async iterators (issue #1104) (#1107)
1 parent 5de0ad7 commit b5923ca

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+616
-7
lines changed

‎src/coverlet.core/Symbols/CecilSymbolHelper.cs

+288-5
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‎test/coverlet.core.tests/Coverage/CoverageTests.AsyncForeach.cs

+66
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@@ -0,0 +1,66 @@
1+
using System.Collections.Generic;
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using System.IO;
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using System.Linq;
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using System.Threading.Tasks;
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using Coverlet.Core.Samples.Tests;
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using Coverlet.Tests.Xunit.Extensions;
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using Xunit;
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namespace Coverlet.Core.Tests
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{
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public partial class CoverageTests
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{
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[Fact]
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public void AsyncForeach()
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{
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string path = Path.GetTempFileName();
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try
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{
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FunctionExecutor.Run(async (string[] pathSerialize) =>
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{
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CoveragePrepareResult coveragePrepareResult = await TestInstrumentationHelper.Run<AsyncForeach>(instance =>
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{
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int res = ((ValueTask<int>)instance.SumWithATwist(AsyncEnumerable.Range(1, 5))).GetAwaiter().GetResult();
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res += ((ValueTask<int>)instance.Sum(AsyncEnumerable.Range(1, 3))).GetAwaiter().GetResult();
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res += ((ValueTask<int>)instance.SumEmpty()).GetAwaiter().GetResult();
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return Task.CompletedTask;
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}, persistPrepareResultToFile: pathSerialize[0]);
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return 0;
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}, new string[] { path });
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TestInstrumentationHelper.GetCoverageResult(path)
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.Document("Instrumentation.AsyncForeach.cs")
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.AssertLinesCovered(BuildConfiguration.Debug,
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// SumWithATwist(IAsyncEnumerable<int>)
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// Apparently due to entering and exiting the async state machine, line 17
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// (the top of an "await foreach" loop) is reached three times *plus* twice
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// per loop iteration. So, in this case, with five loop iterations, we end
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// up with 3 + 5 * 2 = 13 hits.
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(14, 1), (15, 1), (17, 13), (18, 5), (19, 5), (20, 5), (21, 5), (22, 5),
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(24, 0), (25, 0), (26, 0), (27, 5), (29, 1), (30, 1),
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// Sum(IAsyncEnumerable<int>)
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(34, 1), (35, 1), (37, 9), (38, 3), (39, 3), (40, 3), (42, 1), (43, 1),
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// SumEmpty()
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(47, 1), (48, 1), (50, 3), (51, 0), (52, 0), (53, 0), (55, 1), (56, 1)
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)
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.AssertBranchesCovered(BuildConfiguration.Debug,
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// SumWithATwist(IAsyncEnumerable<int>)
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(17, 2, 1), (17, 3, 5), (19, 0, 5), (19, 1, 0),
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// Sum(IAsyncEnumerable<int>)
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(37, 0, 1), (37, 1, 3),
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// SumEmpty()
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// If we never entered the loop, that's a branch not taken, which is
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// what we want to see.
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(50, 0, 1), (50, 1, 0)
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)
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.ExpectedTotalNumberOfBranches(BuildConfiguration.Debug, 4);
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}
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finally
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{
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File.Delete(path);
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}
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}
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}
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}

‎test/coverlet.core.tests/Coverage/CoverageTests.AsyncIterator.cs

+52
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@@ -0,0 +1,52 @@
1+
using System.Collections.Generic;
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using System.IO;
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using System.Threading.Tasks;
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using Coverlet.Core.Samples.Tests;
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using Coverlet.Tests.Xunit.Extensions;
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using Xunit;
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namespace Coverlet.Core.Tests
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{
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public partial class CoverageTests
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{
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[Fact]
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public void AsyncIterator()
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{
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string path = Path.GetTempFileName();
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try
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{
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FunctionExecutor.Run(async (string[] pathSerialize) =>
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{
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CoveragePrepareResult coveragePrepareResult = await TestInstrumentationHelper.Run<AsyncIterator>(instance =>
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{
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int res = ((Task<int>)instance.Issue1104_Repro()).GetAwaiter().GetResult();
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return Task.CompletedTask;
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}, persistPrepareResultToFile: pathSerialize[0]);
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return 0;
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}, new string[] { path });
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TestInstrumentationHelper.GetCoverageResult(path)
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.Document("Instrumentation.AsyncIterator.cs")
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.AssertLinesCovered(BuildConfiguration.Debug,
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// Issue1104_Repro()
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(14, 1), (15, 1), (17, 203), (18, 100), (19, 100), (20, 100), (22, 1), (23, 1),
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// CreateSequenceAsync()
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(26, 1), (27, 202), (28, 100), (29, 100), (30, 100), (31, 100), (32, 1)
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)
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.AssertBranchesCovered(BuildConfiguration.Debug,
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// Issue1104_Repro(),
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(17, 0, 1), (17, 1, 100),
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// CreateSequenceAsync()
42+
(27, 0, 1), (27, 1, 100)
43+
)
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.ExpectedTotalNumberOfBranches(BuildConfiguration.Debug, 2);
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}
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finally
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{
48+
File.Delete(path);
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}
50+
}
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}
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}

‎test/coverlet.core.tests/Samples/Instrumentation.AsyncForeach.cs

+58
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1+
// Remember to use full name because adding new using directives change line numbers
2+
3+
using System;
4+
using System.Collections.Generic;
5+
using System.Linq;
6+
using System.Threading;
7+
using System.Threading.Tasks;
8+
9+
namespace Coverlet.Core.Samples.Tests
10+
{
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public class AsyncForeach
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{
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async public ValueTask<int> SumWithATwist(IAsyncEnumerable<int> ints)
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{
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int sum = 0;
16+
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await foreach (int i in ints)
18+
{
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if (i > 0)
20+
{
21+
sum += i;
22+
}
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else
24+
{
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sum = 0;
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}
27+
}
28+
29+
return sum;
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}
31+
32+
33+
async public ValueTask<int> Sum(IAsyncEnumerable<int> ints)
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{
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int sum = 0;
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await foreach (int i in ints)
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{
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sum += i;
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}
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return sum;
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}
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45+
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async public ValueTask<int> SumEmpty()
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{
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int sum = 0;
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await foreach (int i in AsyncEnumerable.Empty<int>())
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{
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sum += i;
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}
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return sum;
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}
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}
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}

‎test/coverlet.core.tests/Samples/Instrumentation.AsyncIterator.cs

+34
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1+
// Remember to use full name because adding new using directives change line numbers
2+
3+
using System;
4+
using System.Collections.Generic;
5+
using System.Linq;
6+
using System.Threading;
7+
using System.Threading.Tasks;
8+
9+
namespace Coverlet.Core.Samples.Tests
10+
{
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public class AsyncIterator
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{
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async public Task<int> Issue1104_Repro()
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{
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int sum = 0;
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await foreach (int result in CreateSequenceAsync())
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{
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sum += result;
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}
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return sum;
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}
24+
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async private IAsyncEnumerable<int> CreateSequenceAsync()
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{
27+
for (int i = 0; i < 100; ++i)
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{
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await Task.CompletedTask;
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yield return i;
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}
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}
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}
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}

‎test/coverlet.core.tests/Samples/Samples.cs

+45
Original file line numberDiff line numberDiff line change
@@ -197,6 +197,51 @@ async public ValueTask AsyncAwait()
197197
}
198198
}
199199

200+
public class AwaitForeachStateMachine
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{
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async public ValueTask AsyncAwait(IAsyncEnumerable<int> ints)
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{
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await foreach (int i in ints)
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{
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await default(ValueTask);
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}
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}
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}
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public class AwaitForeachStateMachine_WithBranches
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{
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async public ValueTask<int> SumWithATwist(IAsyncEnumerable<int> ints)
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{
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int sum = 0;
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await foreach (int i in ints)
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{
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if (i > 0)
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{
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sum += i;
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}
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else
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{
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sum = 0;
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}
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}
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return sum;
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}
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}
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public class AsyncIteratorStateMachine
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{
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async public IAsyncEnumerable<int> CreateSequenceAsync()
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{
237+
for (int i = 0; i < 100; ++i)
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{
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await Task.CompletedTask;
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yield return i;
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}
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}
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}
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200245
[ExcludeFromCoverage]
201246
public class ClassExcludedByCoverletCodeCoverageAttr
202247
{

‎test/coverlet.core.tests/Symbols/CecilSymbolHelperTests.cs

+69
Original file line numberDiff line numberDiff line change
@@ -310,6 +310,75 @@ public void GetBranchPoints_IgnoresBranchesIn_AsyncAwaitValueTaskStateMachine()
310310
Assert.Empty(points);
311311
}
312312

313+
[Fact]
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public void GetBranchPoints_IgnoresMostBranchesIn_AwaitForeachStateMachine()
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{
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// arrange
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var nestedName = typeof(AwaitForeachStateMachine).GetNestedTypes(BindingFlags.NonPublic).First().Name;
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var type = _module.Types.FirstOrDefault(x => x.FullName == typeof(AwaitForeachStateMachine).FullName);
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var nestedType = type.NestedTypes.FirstOrDefault(x => x.FullName.EndsWith(nestedName));
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var method = nestedType.Methods.First(x => x.FullName.EndsWith("::MoveNext()"));
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// act
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var points = _cecilSymbolHelper.GetBranchPoints(method);
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// assert
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// We do expect there to be a two-way branch (stay in the loop or not?) on
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// the line containing "await foreach".
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Assert.NotNull(points);
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Assert.Equal(2, points.Count());
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Assert.Equal(points[0].Offset, points[1].Offset);
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Assert.Equal(204, points[0].StartLine);
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Assert.Equal(204, points[1].StartLine);
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}
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[Fact]
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public void GetBranchPoints_IgnoresMostBranchesIn_AwaitForeachStateMachine_WithBranchesWithinIt()
337+
{
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// arrange
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var nestedName = typeof(AwaitForeachStateMachine_WithBranches).GetNestedTypes(BindingFlags.NonPublic).First().Name;
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var type = _module.Types.FirstOrDefault(x => x.FullName == typeof(AwaitForeachStateMachine_WithBranches).FullName);
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var nestedType = type.NestedTypes.FirstOrDefault(x => x.FullName.EndsWith(nestedName));
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var method = nestedType.Methods.First(x => x.FullName.EndsWith("::MoveNext()"));
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// act
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var points = _cecilSymbolHelper.GetBranchPoints(method);
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// assert
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// We do expect there to be four branch points (two places where we can branch
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// two ways), one being the "stay in the loop or not?" branch on the line
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// containing "await foreach" and the other being the "if" statement inside
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// the loop.
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Assert.NotNull(points);
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Assert.Equal(4, points.Count());
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Assert.Equal(points[0].Offset, points[1].Offset);
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Assert.Equal(points[2].Offset, points[3].Offset);
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Assert.Equal(219, points[0].StartLine);
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Assert.Equal(219, points[1].StartLine);
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Assert.Equal(217, points[2].StartLine);
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Assert.Equal(217, points[3].StartLine);
360+
}
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362+
[Fact]
363+
public void GetBranchesPoints_IgnoresExtraBranchesIn_AsyncIteratorStateMachine()
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{
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// arrange
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var nestedName = typeof(AsyncIteratorStateMachine).GetNestedTypes(BindingFlags.NonPublic).First().Name;
367+
var type = _module.Types.FirstOrDefault(x => x.FullName == typeof(AsyncIteratorStateMachine).FullName);
368+
var nestedType = type.NestedTypes.FirstOrDefault(x => x.FullName.EndsWith(nestedName));
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var method = nestedType.Methods.First(x => x.FullName.EndsWith("::MoveNext()"));
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// act
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var points = _cecilSymbolHelper.GetBranchPoints(method);
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// assert
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// We do expect the "for" loop to be a branch with two branch points, but that's it.
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Assert.NotNull(points);
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Assert.Equal(2, points.Count());
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Assert.Equal(237, points[0].StartLine);
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Assert.Equal(237, points[1].StartLine);
380+
}
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313382
[Fact]
314383
public void GetBranchPoints_ExceptionFilter()
315384
{

‎test/coverlet.core.tests/coverlet.core.tests.csproj

+4-2
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@@ -30,9 +30,11 @@
3030

3131
<ItemGroup>
3232
<!--For test TestInstrument_NetstandardAwareAssemblyResolver_PreserveCompilationContext-->
33-
<PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="2.2.0" />
33+
<PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="5.0.0" />
3434
<!--For test issue 809 https://github.com/coverlet-coverage/coverlet/issues/809-->
35-
<PackageReference Include="LinqKit.Microsoft.EntityFrameworkCore" Version="2.0.0" />
35+
<PackageReference Include="LinqKit.Microsoft.EntityFrameworkCore" Version="5.0.23" />
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<!--To test issue 1104 https://github.com/coverlet-coverage/coverlet/issues/1104-->
37+
<PackageReference Include="System.Linq.Async" Version="5.0.0" />
3638
</ItemGroup>
3739

3840
<ItemGroup>

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