[Quality] Add code formatter and linter (#326)

format.sh

@@ -0,0 +1,108 @@
+#!/usr/bin/env bash
+# YAPF formatter, adapted from ray and skypilot.
+#
+# Usage:
+#    # Do work and commit your work.
+
+#    # Format files that differ from origin/main.
+#    bash format.sh
+
+#    # Commit changed files with message 'Run yapf and pylint'
+#
+#
+# YAPF + Clang formatter (if installed). This script formats all changed files from the last mergebase.
+# You are encouraged to run this locally before pushing changes for review.
+
+# Cause the script to exit if a single command fails
+set -eo pipefail
+
+# this stops git rev-parse from failing if we run this from the .git directory
+builtin cd "$(dirname "${BASH_SOURCE:-$0}")"
+ROOT="$(git rev-parse --show-toplevel)"
+builtin cd "$ROOT" || exit 1
+
+YAPF_VERSION=$(yapf --version | awk '{print $2}')
+PYLINT_VERSION=$(pylint --version | head -n 1 | awk '{print $2}')
+MYPY_VERSION=$(mypy --version | awk '{print $2}')
+
+# # params: tool name, tool version, required version
+tool_version_check() {
+    if [[ $2 != $3 ]]; then
+        echo "Wrong $1 version installed: $3 is required, not $2."
+        exit 1
+    fi
+}
+
+tool_version_check "yapf" $YAPF_VERSION "$(grep yapf requirements-dev.txt | cut -d'=' -f3)"
+tool_version_check "pylint" $PYLINT_VERSION "$(grep "pylint==" requirements-dev.txt | cut -d'=' -f3)"
+tool_version_check "mypy" "$MYPY_VERSION" "$(grep mypy requirements-dev.txt | cut -d'=' -f3)"
+
+YAPF_FLAGS=(
+    '--recursive'
+    '--parallel'
+)
+
+YAPF_EXCLUDES=(
+    '--exclude' 'build/**'
+    '--exclude' 'vllm/model_executor/parallel_utils/**'
+)
+
+# Format specified files
+format() {
+    yapf --in-place "${YAPF_FLAGS[@]}" "$@"
+}
+
+# Format files that differ from main branch. Ignores dirs that are not slated
+# for autoformat yet.
+format_changed() {
+    # The `if` guard ensures that the list of filenames is not empty, which
+    # could cause yapf to receive 0 positional arguments, making it hang
+    # waiting for STDIN.
+    #
+    # `diff-filter=ACM` and $MERGEBASE is to ensure we only format files that
+    # exist on both branches.
+    MERGEBASE="$(git merge-base origin/main HEAD)"
+
+    if ! git diff --diff-filter=ACM --quiet --exit-code "$MERGEBASE" -- '*.py' '*.pyi' &>/dev/null; then
+        git diff --name-only --diff-filter=ACM "$MERGEBASE" -- '*.py' '*.pyi' | xargs -P 5 \
+             yapf --in-place "${YAPF_EXCLUDES[@]}" "${YAPF_FLAGS[@]}"
+    fi
+
+}
+
+# Format all files
+format_all() {
+    yapf --in-place "${YAPF_FLAGS[@]}" "${YAPF_EXCLUDES[@]}" vllm
+}
+
+## This flag formats individual files. --files *must* be the first command line
+## arg to use this option.
+if [[ "$1" == '--files' ]]; then
+   format "${@:2}"
+   # If `--all` is passed, then any further arguments are ignored and the
+   # entire python directory is formatted.
+elif [[ "$1" == '--all' ]]; then
+   format_all
+else
+   # Format only the files that changed in last commit.
+   format_changed
+fi
+echo 'vLLM yapf: Done'
+
+# Run mypy
+# TODO(zhuohan): Enable mypy
+# echo 'vLLM mypy:'
+# mypy
+
+# Run Pylint
+echo 'vLLM Pylint:'
+pylint vllm
+
+if ! git diff --quiet &>/dev/null; then
+    echo 'Reformatted files. Please review and stage the changes.'
+    echo 'Changes not staged for commit:'
+    echo
+    git --no-pager diff --name-only
+
+    exit 1
+fi