Keep dictionary state between the methods in a same class

Question

I have below test class, Where I am defining _cacheExecutor dictionary at class level, and the purpose is mainly to cache the results with type T and test data as keys.

public class CodesAndGuidelinesTest : SchemaCache, IClassFixture<PostgreSqlResource>  
{         
    private readonly Dictionary<(Type, object), Task<IRequestExecutor>> _cacheExecutor = new();  
    public CodesAndGuidelinesTest(PostgreSqlResource resource) :base(resource) { }  

    [Fact]  
    public async Task Create_Name_Contains_Expression()  
    {  
        IRequestExecutor requestExecutor = await CreateSchemaAsync(CodesAndGuidelinesMockFixture.codeStandardGuidelines, _cacheExecutor);  
        .......  
        .......    
    }  

    [Fact]  
    public async Task Create_Name_NotContains_Expression()  
    {  
        IRequestExecutor requestExecutor = await CreateSchemaAsync(CodesAndGuidelinesMockFixture.codeStandardGuidelines, _cacheExecutor);  
        .......  
        .......    
    }  
}  

Below is the SchemaCache class

public class SchemaCache : QueryTestBase  
{  
    public SchemaCache(PostgreSqlResource resouce) : base(resouce) { }  
    public Task<IRequestExecutor> CreateSchemaAsync<T>(T[] entities,  
                                                       Dictionary<(Type, object), Task<IRequestExecutor>> cacheExecutor) where T : class  
    {  
        (Type, T[] entites) key = (typeof(T), entities);  
        if (cacheExecutor.TryGetValue(key, out var result))  
        {  
            return result;  
        }  
        else // else block will always be executed when I run the test methods all at once  
        {  
            cacheExecutor[key] = CreateDb(entities);  
        }  
        return cacheExecutor[key];  
    }  
}  

In the above class, I store the test data and type combined as keys in the dictionary and the results Task<IRequestExecutor> as values.

When executing the test methods all at once, For the first test method, it goes to the createDb, and the keys and values are stored in _cacheExecutor, and for the following test method _cacheExecutor has null values and thus it's going into the else block. The else block will always be executed because of the dictionary at class-level declaration, and for the new method, the _cacheExecutor will be null.

Could anyone please let me know any better solution or suggestion?

Thanks in advance!!

Answer 1

No matter the test framework it's generally acceptable to perform a setup for each test method. For example, NUnit is [SetUp] public void Init() and teardown [TearDown] public void Cleanup() and MTest [TestInitialize] and [TestCleanup] to name a few. This way a test method is not polluted by other test methods.

Perhaps that will help.