tools: Add git utility scripts.

tools/clean-branches

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+set -e
+
+# usage: clean-branches
+# Deletes any local branches which are ancestors of origin/master,
+# and also any branches in origin which are ancestors of
+# origin/master and are named like $USER-*.
+
+# usage: clean-branches --reviews
+# Deletes all the above mentioned branches as well as branches
+# created by the scripts like `fetch-rebase-pull-request`. Be careful
+# as this would also remove other branches woth names like review-*
+
+review=0
+if [ $# -ne 0 ] && [ "$1" == "--reviews" ]; then
+    review=1
+fi
+push_args=()
+
+function is_merged {
+    ! git rev-list -n 1 origin/master.."$1" | grep -q .
+}
+
+function clean_ref {
+    ref="$1"
+    case "$ref" in
+        */master | */HEAD)
+            return
+            ;;
+
+        refs/heads/review-*)
+            if [ $review -ne 0 ]; then
+                echo -n "Deleting local branch $(echo "$ref" | sed 's!^refs/heads/!!')"
+                echo " (was $(git rev-parse --short "$ref"))"
+                git update-ref -d "$ref"
+            fi
+            ;;
+
+        refs/heads/*)
+            if is_merged "$ref"; then
+                echo -n "Deleting local branch $(echo "$ref" | sed 's!^refs/heads/!!')"
+                echo " (was $(git rev-parse --short "$ref"))"
+                git update-ref -d "$ref"
+            fi
+            ;;
+
+        refs/remotes/origin/$USER-*)
+            if is_merged "$ref"; then
+                remote_name="$(echo "$ref" | sed 's!^refs/remotes/origin/!!')"
+                echo -n "Deleting remote branch $remote_name"
+                echo " (was $(git rev-parse --short "$ref"))"
+                # NB: this won't handle spaces in ref names
+                push_args=("${push_args[@]}" ":$remote_name")
+            fi
+            ;;
+    esac
+}
+
+if [ "$(git symbolic-ref HEAD)" != 'refs/heads/master' ]; then
+    echo "Check out master before you run this script." >&2
+    exit 1
+fi
+
+git fetch --prune origin
+
+eval "$(git for-each-ref --shell --format='clean_ref %(refname);')"
+
+if [ "${#push_args}" -ne 0 ]; then
+    git push origin "${push_args[@]}"
+fi

tools/clean-repo

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -e
+
+# Remove .pyc files to prevent loading stale code.
+#
+# You can run it automatically on checkout:
+#
+#     echo ./tools/clean-repo > .git/hooks/post-checkout
+#     chmod +x .git/hooks/post-checkout
+
+cd "$(dirname "$0")/.."
+find . -name "*.pyc" -exec rm -f {} \;
+find . -name "__pycache__" -prune -exec rm -rf {} \;

tools/deploy-branch

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+function error_out {
+    echo -en '\e[0;31m'
+    echo "$1"
+    echo -en '\e[0m'
+    exit 1
+}
+
+status=$(git status --porcelain | grep -v '^??')
+[ ! -z "$status" ] && error_out "Working directory or index not clean"
+
+old_ref=$(git rev-list --max-count=1 HEAD)
+branch=$1
+branch_ref=$(git rev-list --max-count=1 "$branch")
+
+[ $? -ne 0 ] && error_out "Unknown branch: $branch"
+
+if [ "$old_ref" == "$branch_ref" ]; then
+    new_ref=master
+else
+    ref_name=$(git describe --all --exact "$old_ref")
+    if [ $? -eq 0 ]; then
+        new_ref=$(echo "$ref_name" | perl -pe 's{^(heads|remotes)/}{}')
+    else
+        new_ref=$old_ref
+    fi
+fi
+
+[ -z "$branch" ] && error_out "You must specify a branch name to deploy"
+
+git fetch -p
+
+git rebase origin/master "$branch"
+[ $? -ne 0 ] && error_out "Rebase onto origin/master failed"
+
+git push . HEAD:master
+git push origin master
+[ $? -ne 0 ] && error_out "Push of master to origin/master failed"
+
+git checkout "$new_ref"
+git branch -D "$branch"
+git push origin ":$branch"

tools/fetch-pull-request

@@ -0,0 +1,16 @@
+#!/bin/bash
+set -e
+set -x
+
+if ! git diff-index --quiet HEAD; then
+    set +x
+    echo "There are uncommitted changes:"
+    git status --short
+    echo "Doing nothing to avoid losing your work."
+    exit 1
+fi
+request_id="$1"
+remote=${2:-"upstream"}
+git fetch "$remote" "pull/$request_id/head"
+git checkout -B "review-original-${request_id}"
+git reset --hard FETCH_HEAD

tools/fetch-rebase-pull-request

@@ -0,0 +1,17 @@
+#!/bin/bash
+set -e
+set -x
+
+if ! git diff-index --quiet HEAD; then
+    set +x
+    echo "There are uncommitted changes:"
+    git status --short
+    echo "Doing nothing to avoid losing your work."
+    exit 1
+fi
+request_id="$1"
+remote=${2:-"upstream"}
+git fetch "$remote" "pull/$request_id/head"
+git checkout -B "review-${request_id}" $remote/master
+git reset --hard FETCH_HEAD
+git pull --rebase

tools/reset-to-pull-request

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -e
+set -x
+
+if ! git diff-index --quiet HEAD; then
+    set +x
+    echo "There are uncommitted changes:"
+    git status --short
+    echo "Doing nothing to avoid losing your work."
+    exit 1
+fi
+request_id="$1"
+remote=${2:-"upstream"}
+git fetch "$remote" "pull/$request_id/head"
+git reset --hard FETCH_HEAD

tools/review

@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+
+from __future__ import print_function
+import subprocess
+import sys
+
+def exit(message):
+    # type: (str) -> None
+    print('PROBLEM!')
+    print(message)
+    sys.exit(1)
+
+def run(command):
+    # type: (str) -> None
+    print('\n>>> ' + command)
+    subprocess.check_call(command.split())
+
+def check_output(command):
+    # type: (str) -> str
+    return subprocess.check_output(command.split()).decode('ascii')
+
+def get_git_branch():
+    # type: () -> str
+    command = 'git rev-parse --abbrev-ref HEAD'
+    output = check_output(command)
+    return output.strip()
+
+def check_git_pristine():
+    # type: () -> None
+    command = 'git status --porcelain'
+    output = check_output(command)
+    if output.strip():
+        exit('Git is not pristine:\n' + output)
+
+def ensure_on_clean_master():
+    # type: () -> None
+    branch = get_git_branch()
+    if branch != 'master':
+        exit('You are still on a feature branch: %s' % (branch,))
+    check_git_pristine()
+    run('git fetch upstream master')
+    run('git rebase upstream/master')
+
+def create_pull_branch(pull_id):
+    # type: (int) -> None
+    run('git fetch upstream pull/%d/head' % (pull_id,))
+    run('git checkout -B review-%s FETCH_HEAD' % (pull_id,))
+    run('git rebase upstream/master')
+    run('git log upstream/master.. --oneline')
+    run('git diff upstream/master.. --name-status')
+
+    print()
+    print('PR: %d' % (pull_id,))
+    print(subprocess.check_output(['git', 'log', 'HEAD~..',
+                                   '--pretty=format:Author: %an']))
+
+def review_pr():
+    # type: () -> None
+    try:
+        pull_id = int(sys.argv[1])
+    except Exception:
+        exit('please provide an integer pull request id')
+
+    ensure_on_clean_master()
+    create_pull_branch(pull_id)
+
+if __name__ == '__main__':
+    review_pr()