Clear the efficiency-improver backlog: OTel tags and analyzer member lookup

src/Analyzers/MSTest.Analyzers/DynamicDataShouldBeValidAnalyzer.cs

@@ -179,20 +179,36 @@ private static (ISymbol? Member, bool AreTooMany) TryGetMember(INamedTypeSymbol
  return (null, false);
  }
 
- ISymbol? potentialProperty = potentialMembers.FirstOrDefault(m => m.Kind == SymbolKind.Property);
- if (potentialProperty is not null)
+ // Single pass over the members: a property always wins, otherwise the first method is used and
+ // more than one method is an error. Doing this with FirstOrDefault + Where().ToImmutableArray()
+ // scanned the members twice and allocated an array per [DynamicData] attribute per compilation.
+ ISymbol? firstMethod = null;
+ bool hasMultipleMethods = false;
+ foreach (ISymbol member in potentialMembers)
  {
- return (potentialProperty, false);
- }
-
- var candidateMethods = potentialMembers.Where(m => m.Kind == SymbolKind.Method).ToImmutableArray();
- if (candidateMethods.Length > 1)
- {
- // If there are multiple methods with the same name, report a diagnostic. This is not a supported scenario.
- return (null, true);
+ switch (member.Kind)
+ {
+ case SymbolKind.Property:
+ return (member, false);
+
+ case SymbolKind.Method:
+ if (firstMethod is null)
+ {
+ firstMethod = member;
+ }
+ else
+ {
+ hasMultipleMethods = true;
+ }
+
+ break;
+ }
  }
 
- return (candidateMethods.IsEmpty ? potentialMembers[0] : candidateMethods[0], false);
+ // If there are multiple methods with the same name, report a diagnostic. This is not a supported scenario.
+ return hasMultipleMethods
+ ? (null, true)
+ : (firstMethod ?? potentialMembers[0], false);
  }
  }
 

src/Platform/Microsoft.Testing.Platform/Telemetry/OpenTelemetryResultHandler.cs

@@ -318,7 +318,35 @@ private static string GetRunResultStatus(int failedTests, int exitCode)
  }
  }
 
- if (testNode.Properties.SingleOrDefault<TestMethodIdentifierProperty>() is { } identifierProperty)
+ // Single pass over the property bag for the two singleton properties below: two separate
+ // SingleOrDefault<T>() calls walked the whole bag once each.
+ TestMethodIdentifierProperty? identifierProperty = null;
+ TestFileLocationProperty? testLocationProperty = null;
+ PropertyBag.PropertyBagEnumerator enumerator = testNode.Properties.GetStructEnumerator();
+ while (enumerator.MoveNext())
+ {
+ switch (enumerator.Current)
+ {
+ case TestMethodIdentifierProperty identifier:
+ if (identifierProperty is not null)
+ {
+ throw new InvalidOperationException($"Found multiple properties of type '{typeof(TestMethodIdentifierProperty)}'.");
+ }
+
+ identifierProperty = identifier;
+ break;
+ case TestFileLocationProperty location:
+ if (testLocationProperty is not null)
+ {
+ throw new InvalidOperationException($"Found multiple properties of type '{typeof(TestFileLocationProperty)}'.");
+ }
+
+ testLocationProperty = location;
+ break;
+ }
+ }
+
+ if (identifierProperty is not null)
  {
  // code.function.name is defined as the *fully qualified* name; there is no separate namespace
  // attribute (code.namespace is deprecated upstream).
@@ -335,7 +363,7 @@ private static string GetRunResultStatus(int failedTests, int exitCode)
  }
  }
 
- if (testNode.Properties.SingleOrDefault<TestFileLocationProperty>() is { } testLocationProperty)
+ if (testLocationProperty is not null)
  {
  yield return new(TestingPlatformSemanticConventions.Attributes.CodeFilePath, testLocationProperty.FilePath);
  yield return new(TestingPlatformSemanticConventions.Attributes.CodeLineNumber, testLocationProperty.LineSpan.Start.Line);
@@ -348,8 +376,16 @@ private static string GetRunResultStatus(int failedTests, int exitCode)
  }
  }
 
- foreach (TestMetadataProperty metadata in testNode.Properties.OfType<TestMetadataProperty>())
+ // The metadata is yielded after the blocks above, so it needs its own pass. OfType<TestMetadataProperty>()
+ // would materialize a TProperty[] just to enumerate it once; the struct enumerator allocates nothing.
+ PropertyBag.PropertyBagEnumerator metadataEnumerator = testNode.Properties.GetStructEnumerator();
+ while (metadataEnumerator.MoveNext())
  {
+ if (metadataEnumerator.Current is not TestMetadataProperty metadata)
+ {
+ continue;
+ }
+
  yield return new KeyValuePair<string, object?>($"{TestingPlatformSemanticConventions.Attributes.TestMetadataPrefix}{metadata.Key}", metadata.Value);
  if (_options.EmitLegacyAttributes)
  {

test/UnitTests/Microsoft.Testing.Platform.UnitTests/Telemetry/OpenTelemetryResultHandlerTests.cs

@@ -721,6 +721,29 @@ public void NotifyInProgress_ForTheGlobalNamespace_DoesNotEmitALeadingDot(string
  }
 
  private IEnumerable<KeyValuePair<string, object?>>? CaptureInProgressTags(TestMethodIdentifierProperty identifierProperty)
+ => CaptureInProgressTags(new PropertyBag(identifierProperty));
+
+ [TestMethod]
+ public void NotifyInProgress_WithDuplicateIdentifierProperty_Throws()
+ {
+ InvalidOperationException exception = Assert.ThrowsExactly<InvalidOperationException>(() => CaptureInProgressTags(new PropertyBag(
+ new TestMethodIdentifierProperty("MyAssembly", "My.Namespace", "MyClass", "MyMethod", 0, [], "void"),
+ new TestMethodIdentifierProperty("MyAssembly", "My.Namespace", "MyClass", "MyOtherMethod", 0, [], "void"))));
+
+ Assert.AreEqual($"Found multiple properties of type '{typeof(TestMethodIdentifierProperty)}'.", exception.Message);
+ }
+
+ [TestMethod]
+ public void NotifyInProgress_WithDuplicateFileLocationProperty_Throws()
+ {
+ InvalidOperationException exception = Assert.ThrowsExactly<InvalidOperationException>(() => CaptureInProgressTags(new PropertyBag(
+ new TestFileLocationProperty("first.cs", new LinePositionSpan(new LinePosition(1, 0), new LinePosition(2, 0))),
+ new TestFileLocationProperty("second.cs", new LinePositionSpan(new LinePosition(3, 0), new LinePosition(4, 0))))));
+
+ Assert.AreEqual($"Found multiple properties of type '{typeof(TestFileLocationProperty)}'.", exception.Message);
+ }
+
+ private IEnumerable<KeyValuePair<string, object?>>? CaptureInProgressTags(PropertyBag properties)
  {
  IEnumerable<KeyValuePair<string, object?>>? capturedTags = null;
  _otelService.Setup(s => s.StartActivity(
@@ -736,7 +759,7 @@ public void NotifyInProgress_ForTheGlobalNamespace_DoesNotEmitALeadingDot(string
  {
  Uid = new TestNodeUid("fqn"),
  DisplayName = "Test",
- Properties = new PropertyBag(identifierProperty),
+ Properties = properties,
  },
  null);