How to compare Go benchmark in TravisCI

Although the article is for Go, but you still can use concept part for others language.

Frist we create a script called bench_compare.sh:

if ["${TRAVIS_PULL_REQUEST_BRANCH:-$TRAVIS_BRANCH}" != "master"]; then
    REMOTE_URL="$(git config --get remote.origin.url)";
    cd ${TRAVIS_BUILD_DIR}/.. && \
    git clone ${REMOTE_URL} "${TRAVIS_REPO_SLUG}-bench" && \
    cd "${TRAVIS_REPO_SLUG}-bench" && \
    git checkout master && \
    go test -bench . ./... > master_bench.out && \
    git checkout ${TRAVIS_COMMIT} && \
    go test -bench . ./... > current_bench.out && \
    go get golang.org/x/tools/cmd/benchcmp && \
    benchcmp master_bench.out current_bench.out;
fi

Then I usually would execute it at after_success this section,.travis.yml:

script:
  # testing part
after_success:
  # ignore
  - bash ./bench_compare.sh

p.s. write script part is just want to tell you it’s located at that indention

Now let me explain the script, basically we peek ${TRAVIS_PULL_REQUEST_BRANCH:-$TRAVIS_BRANCH} is not master first. To make sure we are not at master branch, if we are not at master, then we start to compare the benchmark result. Here has a point, $(git config --get remote.origin.url) is required, you can write git checkout master to know why. Then we checkout master and ${TRAVIS_COMMIT}(I think this variable already tell you what is it), do benchmarking and store them. Final step we download golang.org/x/tools/cmd/benchcmp for comparing, and compare two result file.

To get more info, you can reference:

• travis default variables
• godoc.org/golang.org/x/tools/cmd/benchcmp

Thanks for reading