Compilation Flags

unittest2 behavior can be customized using compilation flags (-d:flag). These flags allow you to select the execution model, enable advanced features, and configure compatibility with the standard library.

Execution Modes

• -d:unittest2Compat=true|false: Select execution mode (default is true).
  • true: Compatibility Mode. Single-pass execution, identical to std/unittest.
  • false: Collect-and-Run Mode. Two-phase execution (discovery then run). See Operation Modes for details.
  • Set with -d:unittest2Compat=false to disable compatibility mode.

Advanced Features

• -d:unittest2Static=true: Enable Compile-Time Execution.
  • Runs your tests in the Nim VM during compilation.
  • Verifies that your code works correctly at compile-time.
  • Use staticTest, runtimeTest, or dualTest for explicit control.
  • Set with -d:unittest2Static=true.
• -d:unittest2ListTests=true: List Tests without running them.
  • Useful for integration with external test runners or IDEs.
  • Requires Collect-and-Run Mode (-d:unittest2Compat=false).
  • Set with -d:unittest2ListTests=true.
• -d:unittest2DisableParamFiltering=true: Disable automatic argument parsing.
  • Use this if your test binary needs to handle its own CLI arguments. Call parseParameters manually if needed.
  • Set with -d:unittest2DisableParamFiltering=true.
• -d:unittest2NoCollect=true: Disable test collection mode.
  • This is an experimental feature that affects the order in which tests and suites are evaluated.
  • Set with -d:unittest2NoCollect=true.
• -d:unittest2PreviewIsolate=true: Enable preview isolation mode.
  • Each test is run in a separate process to ensure complete isolation. This may be removed in the future.
  • Set with -d:unittest2PreviewIsolate=true.

Standard Library Compatibility

These flags provide compatibility with the original unittest module:

• -d:nimUnittestOutputLevel=VERBOSE|COMPACT|FAILURES|NONE: Set the default output level at compile time.
• -d:nimUnittestColor=auto|on|off: Set the color output mode at compile time.
• -d:nimUnittestAbortOnError=true: Set whether to abort on the first error at compile time.