Example File Testing

SKILL: Example File Testing Pattern

Confidence: low Source: earned

What

When testing parsers or loaders in SqncR, use the actual example .sqnc.yaml files from examples/ as test fixtures rather than constructing synthetic YAML in tests. This gives real-world coverage and catches deserialization issues that synthetic tests miss.

How

private static string ExamplesDir =>
    Path.Combine(AppContext.BaseDirectory, "..", "..", "..", "..", "..", "examples");

[Theory]
[InlineData("chill-ambient.sqnc.yaml", "Late Night Ambient", 70, "Cm")]
public void Parse_ExampleFile_ReturnsCorrectMeta(string fileName, string expectedTitle, int expectedTempo, string expectedKey)
{
    var path = Path.GetFullPath(Path.Combine(ExamplesDir, fileName));
    var seq = _parser.Parse(path);
    Assert.Equal(expectedTitle, seq.Meta.Title);
}

Key Points

• Use AppContext.BaseDirectory + relative path traversal to find examples/ from test bin output directory
• Use Path.GetFullPath() to normalize the path
• Parameterize with [Theory]/[InlineData] so each example file is a separate test case
• Document known deserialization failures as explicit Assert.ThrowsAny<Exception>() tests — don't just skip broken files
• When an example file can't be parsed due to model limitations, that's a finding worth documenting as a decision

Caveats

• Path traversal depth (.. count) depends on the test project's position relative to repo root — currently 5 levels from tests/SqncR.Core.Tests/bin/Debug/net9.0/
• If the project structure changes, the path needs updating