rust/ui_test/README.md

A smaller version of compiletest-rs

Magic behavior

• Tests are run in order of their filenames (files first, then recursing into folders). So if you have any slow tests, prepend them with a small integral number to make them get run first, taking advantage of parallelism as much as possible (instead of waiting for the slow tests at the end).

Supported magic comment annotations

Note that the space after //, when it is present, is not optional -- it must be exactly one.

• // ignore-XXX avoids running the test on targets whose triple contains XXX
  • XXX can also be one of 64bit, 32bit or 16bit
• // only-XXX avoids running the test on targets whose triple does not contain XXX
  • XXX can also be one of 64bit, 32bit or 16bit
• // stderr-per-bitwidth produces one stderr file per bitwidth, as they may differ significantly sometimes
• // error-pattern: XXX make sure the stderr output contains XXX
• //~ ERROR: XXX make sure the stderr output contains XXX for an error in the line where this comment is written
  • Also supports HELP, WARN or NOTE for different kind of message
    • if one of those levels is specified explicitly, all diagnostics of this level or higher need an annotation. If you want to avoid this, just leave out the all caps level note entirely.
  • If the all caps note is left out, a message of any level is matched. Leaving it out is not allowed for ERROR levels.
  • This checks the output before normalization, so you can check things that get normalized away, but need to be careful not to accidentally have a pattern that differs between platforms.
• // revisions: XXX YYY runs the test once for each space separated name in the list
  • emits one stderr file per revision
  • //~ comments can be restricted to specific revisions by adding the revision name before the ~ in square brackets: //[XXX]~
• // compile-flags: XXX appends XXX to the command line arguments passed to the rustc driver
• // rustc-env: XXX=YYY sets the env var XXX to YYY for the rustc driver execution.
  • for Miri these env vars are used during compilation via rustc and during the emulation of the program
• // normalize-stderr-test: "REGEX" -> "REPLACEMENT" replaces all matches of REGEX in the stderr with REPLACEMENT. The replacement may specify $1 and similar backreferences to paste captures.

Significant differences to compiletest-rs

• ignore-* and only-* opereate solely on the triple, instead of supporting things like macos
• only //~ comments can be individualized per revision