Scribbles for my bad memory

I had written the following code in a project

   ...
   return s && s.value || null

It works well for some days until a colleague did some code refactoring. In the beginning, s.value is a string value, and an empty string is not a valid value, so the code works well. After the refactoring, s.value became an integer, and this time 0 is a valid value. So you can imagine when s.value === 0 the code above will return null instead of 0. It leads to a bug!

Therefore please use the"A || B" expression with caution!

Two articles explain well this subject. One is in Chinese, the other is in English.

• 中文
• English

1. Present enums as string. Modify your StartUp.cs, add the highlight part below:

            services.AddMemoryCache().AddMvcCore().AddJsonOptions(opts =>
                {
                    opts.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
                })
                .AddDataAnnotationsLocalization();
 

2. Enable XML Comments

   1. Manually add the two lines in PropertyGroup below to the .csproj file:

<PropertyGroup>
  <GenerateDocumentationFile>true</GenerateDocumentationFile>
  <NoWarn>$(NoWarn);1591</NoWarn>
</PropertyGroup>

2. Add the options in the code below 

            services.AddSwaggerGen(options =>
            {
                options.IncludeXmlComments(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, $"{AppDomain.CurrentDomain.FriendlyName}.xml"), true);
            });

            await Db.Queryable<Entity>().Where(_ => _.SampleFieldName== sampleFieldValue)
                .GroupBy("AnothterFieldNameInStringFormat")
                .Select<ResultModel>("AnotherFieldNameInStringFormat, Count(AnotherFieldNameInStringFormat) Total")
                .ToListAsync();