minozzzi/dotfiles/consorcio-api-feature-flags

Feature Flags in Consórcio Simulations API

When implementing feature flags or new environment-based toggles in the consorcio-simulations-api repository, follow these rules to avoid breaking the unit test suite:

1. Avoid Config.cs for Feature Flags

Do NOT add new feature flags directly to src/Consorcio.Simulations.Infra/Configurations/Config.cs. The static constructor of Config.cs enforces the presence of DOTNET_ENVIRONMENT and other environment variables. Unit tests typically run without these variables. If a mapper or service under test accesses Config.cs, it will trigger a TypeInitializationException and break the test suite.

2. Isolate in a Dedicated Static Class

Create a dedicated configuration class (e.g., FeatureFlagConfig.cs) within the Configurations directory.

namespace Consorcio.Simulations.Infra.Configurations;
 
public static class FeatureFlagConfig {
    public static bool EnableMyFeature = bool.Parse(
        Environment.GetEnvironmentVariable("FEATURES_ENABLE_MY_FEATURE") ?? "false"
    );
}

3. Omitting Fields from JSON Payloads

If a disabled feature flag requires completely omitting a field from an external request (e.g., to the Bradesco integration) rather than sending a default value:

1. Make the property nullable (string?, bool?, long?, etc.) in the target DTO.
2. Apply [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)].
3. In the mapping logic, return null if the feature is disabled.

[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
[JsonPropertyName("snExemplo")]
public string? MyField { get; }