Run flake8 against only files that have changed

fast8.sh

#!/bin/bash

set -e

enable_env() {
    local env_name="$1"
    local env_dir=".tox/${env_name}"
    if [ ! -d "${env_dir}" ]; then
        if [ ! -f tox.ini ]; then
            echo 'No tox.ini found' >&2
            exit 1
        elif tox -l | grep -q "^${env_name}$$"; then
            tox -e"${env_name}" --notest
        else
            echo "No ${env_name} tox environment found" >&2
            exit 1
        fi
    fi
    source "${env_dir}"/bin/activate
}

diff_files_branch() {
    local branch=${1:-"@{u}"}
    git diff --name-only --diff-filter=d "${branch}" -- '*.py'
}

diff_files() {
    diff_files_branch 2>/dev/null || diff_files_branch origin/master
}


enable_env pep8
flake8 $(diff_files)