dotnet-testing

name	dotnet-testing
description	Testing patterns and conventions for the AvnDataGenie .NET solution
domain	testing
confidence	high
source	huntress

Context

The AvnDataGenie solution uses xUnit on .NET 10. The test project is src/AvnDataGenie.Tests/. Tests run with dotnet test src/AvnDataGenie.Tests/AvnDataGenie.Tests.csproj.

Patterns

InternalsVisibleTo

AvnDataGenie.csproj has <InternalsVisibleTo Include="AvnDataGenie.Tests" />. Use internal visibility (not public) for methods that need testing but shouldn't be part of the public API.

Test File Organization

One test class per production class or logical unit:

• SqlPromptBuilderTests.cs — tests for SqlPromptBuilder.CreateSystemPromptFromJson()
• CleanAndFormatSqlTests.cs — tests for Generator.CleanAndFormatSql()
• FormatSqlTests.cs — tests for Generator.FormatSql() and Generator.FormatSelectColumns()

Test Data Helpers

Use private static methods to generate test JSON inputs (e.g., MinimalSchemaJson(), RichConfigJson()). Keep test data as close to real shapes as possible — the JSON must match the deserialization models in SqlPromptBuilder.

Pure Functions First

Prioritize testing pure/static methods that have no external dependencies. In this codebase:

• SqlPromptBuilder.CreateSystemPromptFromJson() — public static, takes JSON strings
• Generator.CleanAndFormatSql() — internal static, sanitizes LLM output
• Generator.FormatSql() — internal static, formats SQL
• Generator.FormatSelectColumns() — internal static, formats SELECT columns

SchemaGenerator Requires Integration Tests

SchemaGenerator.Generator.GenerateDatabaseSchemaAsync() requires a live SQL Server connection. Unit tests cannot cover this without a database fixture.

Anti-Patterns

• Don't mock what you can test directly — prefer calling pure functions over mocking IChatClient.
• Don't test formatting by exact string match — use Assert.Contains for structural assertions since the formatting regexes produce complex output.
• Don't skip edge cases — LLM output is unpredictable. Test markdown fences, preambles, trailing commentary, comments, and missing semicolons.