Writing unit tests for C# parsing, binding, and codegen phases

This section will enable you to add unit tests for a new C# language feature: Switch operator (?::). For details on the intended functionality of this operator, read the section, New language feature: Switch Operator (?::), at the start of this chapter.

C# compiler has the following set of unit test projects in Roslyn.sln:

• CSharpCompilerSyntaxTest: This unit tests for parsing and syntax errors.
• CSharpCompilerSemanticTest: This unit tests for semantic errors and semantic model APIs.
• CSharpCompilerSymbolTest: This unit tests for symbols defined in the compiler layer.
• CSharpCommandLineTest: This unit tests for the compiler's command line options.
• CSharpCompilerEmitTest: This unit tests for the code generation phase that verifies the generated MSIL.

In this section, we will add unit tests to CSharpCompilerSyntaxTest...