public void ConcatenationAllocation_Basic()
{
var sampleProgram =
@"using System;
var withBoxing = 5.ToString() + ':' + 8.ToString(); // Boxing on ':'
var withoutBoxing = 5.ToString() + "":"" + 8.ToString();
";
var analyser = new ConcatenationAllocationAnalyzer();
var info = ProcessCode(analyser, sampleProgram, ImmutableArray.Create(SyntaxKind.AddExpression, SyntaxKind.AddAssignmentExpression));
Assert.Equal(1, info.Allocations.Count(d => d.Id == "PAAHeapAnalyzerBoxingRule"));
Assert.Equal(4, info.Allocations.Count(d => d.Id == "PAAHeapAnalyzerStringConcatRule"));
//### CODE ### 5.ToString() + ':' + 8.ToString()
//*** Diagnostic: (9,45): warning HeapAnalyzerBoxingRule: Value type (char) is being boxed to a reference type for a string concatenation.
AssertEx.ContainsDiagnostic(info.Allocations, id: ConcatenationAllocationAnalyzer.ValueTypeToReferenceTypeInAStringConcatenationRule.Id, line: 3, character: 33);
// Diagnostic: (9,43): warning HeapAnalyzerStringConcatRule: Considering using StringBuilder
AssertEx.ContainsDiagnostic(info.Allocations, id: ConcatenationAllocationAnalyzer.StringConcatenationAllocationRule.Id, line: 3, character: 31);
// Diagnostic: (9,49): warning HeapAnalyzerStringConcatRule: Considering using StringBuilder
AssertEx.ContainsDiagnostic(info.Allocations, id: ConcatenationAllocationAnalyzer.StringConcatenationAllocationRule.Id, line: 3, character: 37);
//### CODE ### 5.ToString() + ":" + 8.ToString()
// Diagnostic: (10,46): warning HeapAnalyzerStringConcatRule: Considering using StringBuilder
AssertEx.ContainsDiagnostic(info.Allocations, id: ConcatenationAllocationAnalyzer.StringConcatenationAllocationRule.Id, line: 4, character: 34);
// Diagnostic: (10,52): warning HeapAnalyzerStringConcatRule: Considering using StringBuilder
AssertEx.ContainsDiagnostic(info.Allocations, id: ConcatenationAllocationAnalyzer.StringConcatenationAllocationRule.Id, line: 4, character: 40);
}
public void Non_constant_value_types_in_CSharp_string_concatenation()
{
var @script =
@"char c = 'c'; //F();
string s1 = ""char value will box"" + c;";
var analyser = new ConcatenationAllocationAnalyzer();
var info = ProcessCode(analyser, @script, ImmutableArray.Create(SyntaxKind.AddExpression, SyntaxKind.AddAssignmentExpression));
Assert.AreEqual(1, info.Allocations.Count);
//Diagnostic: (2,53): warning HeapAnalyzerBoxingRule: Value type (char) is being boxed to a reference type for a string concatenation.
AssertEx.ContainsDiagnostic(info.Allocations, ConcatenationAllocationAnalyzer.ValueTypeToReferenceTypeInAStringConcatenationRule.Id, line: 2, character: 53);
}
public void ConcatenationAllocation_Basic()
{
var snippet0 = @"string s0 = ""hello"" + 0.ToString() + ""world"" + 1.ToString();";
var snippet1 = @"string s2 = ""ohell"" + 2.ToString() + ""world"" + 3.ToString() + 4.ToString();";
var analyser = new ConcatenationAllocationAnalyzer();
var info0 = ProcessCode(analyser, snippet0, ImmutableArray.Create(SyntaxKind.AddExpression, SyntaxKind.AddAssignmentExpression));
var info1 = ProcessCode(analyser, snippet1, ImmutableArray.Create(SyntaxKind.AddExpression, SyntaxKind.AddAssignmentExpression));
Assert.AreEqual(0, info0.Allocations.Count(d => d.Id == AllocationRules.StringConcatenationAllocationRule.Id));
Assert.AreEqual(1, info1.Allocations.Count(d => d.Id == AllocationRules.StringConcatenationAllocationRule.Id));
AssertEx.ContainsDiagnostic(info1.Allocations, id: AllocationRules.StringConcatenationAllocationRule.Id, line: 1, character: 13);
}
public void ConcatenationAllocation_DoNotWarnForConst()
{
var snippets = new[]
{
@"const string s0 = nameof(System.String) + ""."" + nameof(System.String);",
@"const string s0 = nameof(System.String) + ""."";",
@"string s0 = nameof(System.String) + ""."" + nameof(System.String);",
@"string s0 = nameof(System.String) + ""."";"
};
var analyser = new ConcatenationAllocationAnalyzer();
foreach (var snippet in snippets)
{
var info = ProcessCode(analyser, snippet, ImmutableArray.Create(SyntaxKind.AddExpression, SyntaxKind.AddAssignmentExpression));
Assert.AreEqual(0, info.Allocations.Count);
}
}
public void ConcatenationAllocation_DoNotWarnForOptimizedValueTypes()
{
var snippets = new[]
{
@"string s0 = nameof(System.String) + '-';",
@"string s0 = nameof(System.String) + true;",
@"string s0 = nameof(System.String) + new System.IntPtr();",
@"string s0 = nameof(System.String) + new System.UIntPtr();"
};
var analyser = new ConcatenationAllocationAnalyzer();
foreach (var snippet in snippets)
{
var info = ProcessCode(analyser, snippet, ImmutableArray.Create(SyntaxKind.AddExpression, SyntaxKind.AddAssignmentExpression));
Assert.AreEqual(0, info.Allocations.Count(x => x.Id == AllocationRules.ValueTypeToReferenceTypeInAStringConcatenationRule.Id));
}
}
