Scand.StormPetrel.FileSnapshotInfrastructure 2.0.0

Scand Storm Petrel File Snapshot Infrastructure

• Overview
• Use Cases
  • By Configuration
    • Default Configuration
    • Default Configuration With Custom Options
    • Custom Configuration
  • By Snapshot Read Kind
    • Text
    • Binary
    • Stream
  • By StormPetrel Use Cases
  • By Test Method Use Case Id
    • Use Case Id in Test Method Parameters
    • No Use Case Id in Test Method Parameters
• Getting Started
• Supported Software
• CHANGELOG
• References

Overview

.NET library that implements Scand.StormPetrel.Generator.Abstraction to rewrite expected baseline files with actual snapshots (HTML, JSON, XML, images, or other bytes). This can be utilized in Snapshot Unit Testing when snapshots are stored as individual files in the file system.

Use Cases

By Configuration

Default Configuration

Rewrites expected baseline files as demonstrated by CalculatorSnapshotTest against the default baseline file structure. Initial baseline files like AddTest.json must exist before StormPetrel auto-generated tests and their origin tests execution because the default appsettings.StormPetrel.json does not specify snapshot file extensions.

Default Configuration With Custom Options

Similar to the Default Configuration, but explicitly specifies the json extension and custom baseline file structure on test assembly initialization in ModuleInitializer. Initial baseline files may not exist before StormPetrel auto-generated tests and their origin tests execution in this case.

Custom Configuration

Rewrites expected baseline files as demonstrated by CalculatorSnapshotTest against a custom baseline file structure. Initial baseline files may not exist before StormPetrel auto-generated tests and their origin tests execution because the custom configuration may specify snapshot file extensions as indicated in CustomSnapshotOptions. See other files in CustomSnapshotInfrastructure for detailed examples of custom configurations.

By Snapshot Read Kind

Text

See ReadAllText method call examples in CalculatorSnapshotTest and other tests.

Binary

See ReadAllBytes method call examples in CalculatorSnapshotTest and other tests.

Stream

See OpenReadWithShareReadWrite method call examples in CalculatorSnapshotTest and other tests.

By StormPetrel Use Cases

StormPetrel supports many use cases based on test framework attributes. All these use cases are supported by the File Snapshot Infrastructure package. Some of them are demonstrated in DefaultConfiguration/CalculatorSnapshotTest and CustomConfiguration/CalculatorSnapshotTest.

By Test Method Use Case Id

Use Case Id in Test Method Parameters

If a test method has useCaseId parameter name or a method parameter marked by UseCaseIdAttribute, then the parameter value is transferred to/from File Snapshot Infrastructure code to get the appropriate snapshot baseline file or folder name. Find useCaseId in DefaultConfiguration/CalculatorSnapshotTest or CustomConfiguration/CalculatorSnapshotTest for more details.

No Use Case Id in Test Method Parameters

If a test method does not have useCaseId parameter name and no method parameter marked by UseCaseIdAttribute, then File Snapshot Infrastructure code treats useCaseId as empty in snapshot baseline file or folder names.

Getting Started

To utilize File Snapshot Infrastructure in a test .NET project:

• Add the Scand.StormPetrel.Generator NuGet package to the project.
• Add the Scand.StormPetrel.FileSnapshotInfrastructure NuGet package to the project.
• Add an appsettings.StormPetrel.json file with Build Action set to C# analyzer additional file according to Scand.StormPetrel.Generator Configuration. The file should reference File Snapshot Infrastructure classes like below:

{
  "GeneratorConfig":
  {
    "DumperExpression": "new Scand.StormPetrel.FileSnapshotInfrastructure.SnapshotDumper()", //Use SnapshotDumper to dump string/binary/stream snapshots stored in actual/expected test variables.
    "RewriterExpression": "new Scand.StormPetrel.FileSnapshotInfrastructure.SnapshotRewriter()" //Use SnapshotRewriter to rewrite snapshot files with actual values.
  },
  "IgnoreInvocationExpressionRegex": "SnapshotProvider", //Ignore SnapshotProvider expressions in Storm Petrel flow.
  "Serilog": null //Optionally disable the logging.
}

See this and other configuration examples in DefaultConfiguration, DefaultConfigurationWithCustomOptions, and CustomConfiguration test projects.

Supported Software

The same as in Scand.StormPetrel.Generator.

CHANGELOG

References

At SCAND, we specialize in building advanced .NET solutions to help businesses develop new or modernize their legacy applications. If you need help getting started with Storm Petrel or support with implementation, we're ready to assist. Whether you're refactoring or rewriting, our team can help solve any challenges you might face. Visit our page to learn more, or reach out for hands-on guidance.