Add new --env-validation argument

Instead of --skip-env-check use the explicit --env-validation argument
for more fine-grained tuning.

Change-Id: Ia89fd98ceb42594a3c5bcece3d593c92d5d697fb
Commit-Queue: Camillo Bruni <>
Reviewed-by: Marja Hölttä <>
3 files changed
tree: 30dd5eeae0ec5102ef6f11c1847d2cb76ee04fce
  1. config/
  2. crossbench/
  3. docs/
  4. tests/
  5. .gitattributes
  6. .gitignore
  7. .pylintrc
  8. .style.yapf
  9. .vpython3
  11. OWNERS
  12. poetry.lock
  14. pyproject.toml
  15. README.chromium


Crossbench is a cross-browser/cross-benchmark runner to extract performance numbers.

Supported Browsers: Chrome/Chromium, Firefox, Safari and Edge.

Supported OS: macOS, linux and windows.


This project uses poetry deps and package scripts to setup the correct environment for testing and debugging.

pip3 install poetry

Install the necessary dependencies from lock file via poetry

poetry install

Basic usage:

poetry run cb speedometer \
    --browser=/path/to/chromium \
    --stories=VanillaJS.* \
    --probe=profiling \

Run Unit tests

poetry run pytest

Run detailed test coverage:

poetry run pytest --cov=crossbench --cov-report=html

Run pytype type checker:

poetry run pytype -j auto crossbench

Main Components


Crossbench supports running benchmarks on one or multiple browser configurations. The main implementation uses selenium for maximum system independence.

You can specify a browser with --browser=<name>. You can repeat the --browser argument to run multiple browser. If you need custom flags for multiple browsers use --browser-config.

poetry run cb speedometer \
    --browser=/path/to/chromium  \
    -- -- \
        --browser-flag-foo \

Browser Config File

For more complex scenarios you can use a browser.config.hjson file. It allows you to specify multiple browser and multiple flag configurations in a single file and produce performance numbers with a single invocation.

poetry run cb speedometer --browser-config=config.hjson

The example file lists and explains all configuration details.


Probes define a way to extract arbitrary (performance) numbers from a host or running browser. This can reach from running simple JS-snippets to extract page-specific numbers to system-wide profiling.

Multiple probes can be added with repeated --probe=XXX options. You can use the describe subcommand to list all probes:

poetry run cb describe probes

Inline Probe Config

Some probes can be configured, either with inline json when using --probe or in a separate --probe-config hjson file. Use the describe command to list all options.

poetry run cb describe probes v8.log
poetry run cb speedometer --probe='v8.log{prof:true}'

Probe Config File

For complex probe setups you can use --probe-config=<file>. The example file lists and explains all configuration details. For the specific probe configuration properties consult the describe command.


Use the describe command to list all benchmark details:

poetry run cb describe benchmarks


Stories define sequences of browser interactions. This can be simply loading a URL and waiting for a given period of time, or in more complex scenarios, actively interact with a page and navigate multiple times.

Use --help or describe to list all stories for a benchmark:

poetry run cb speedometer --help

Use --stories to list individual comma-separated story names, or use a regular expression as filter.

poetry run cb speedometer \
    --browser=/path/to/chromium \