Bash script that fetches issue descriptions from GitHub via curl and adds them into the branch listing from git.

GitHub_Branch_Issues.sh

#!/usr/bin/env bash

# To use this script, go into your GitHub account settings, go into the
# Applications section, and then under `Personal access tokens` click
# `Generate new token`. Name the token whatever you want, give it access
# to the `repo` and `public_repo` scopes (`user` and `gist` are also
# selected by default, but you don't need them for this).
#
# Take the generated token and store it in your personal .gitconfig
# (located at either ~/.gitconfig or ~/.config/git/config on OSX/*nix)
# and put it under github.access-token:
#
# [github]
#     access-token = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
#
# Alternatively, you can run `git config --global github.access-token
# xxxx`, but this will leave the token in your .bash_history file.
#
# On my systems, I also set up a git alias for this script, allowing me
# to call it as `git branches`:
#
# git config --global alias.branches '!~/path/to/this/script.sh'
#

set -euo pipefail
IFS=$'\n\t'

# Default values for arguments
user_token=""
use_cache=true
clear_cache=false
all_branches=false
verbose=false
repo_name=""
repo_owner=""

# Handle command-line arguments
while [[ "${1:-}" = -* ]]; do
    arg="$1"; shift

    case "$arg" in
        --token)
            user_token="$1"
            shift
            ;;
        --clear-cache)
            clear_cache=true
            ;;
        --no-cache)
            use_cache=false
            ;;
        -a)
            all_branches=true
            ;;
        --all)
            all_branches=true
            ;;
        -v)
            verbose=true
            ;;
        --verbose)
            verbose=true
            ;;
    esac
done

rate_limit_remaining=""
cached_issues=""
fetched_issues=""
unknown_issues=""


colors_needed=true
local_branch=""
remote_branch=""
current_branch=""
no_color=`echo -e "\033[0m"`

function colorBranchData {
    if $colors_needed ; then
        colors_needed=false
        local_branch=`git config --get-color color.branch.local white`
        remote_branch=`git config --get-color color.branch.remote red`
        current_branch=`git config --get-color color.branch.current green`
    fi

    if `echo "$1" | grep remotes/ | grep \\\-\> > /dev/null` ; then
        head=`echo "$1" | sed 's/ \->.\{1,\}//'`
        tail=`echo "$1" | sed 's/.\{1,\}\-> //'`
        echo "$remote_branch$head$no_color -> $tail"
    elif `echo "$1" | grep remotes/ > /dev/null` ; then
        echo "$remote_branch$1$no_color$2"
    elif `echo "$1" | grep ^\* > /dev/null` ; then
        no_star="${1:1}"
        echo "$no_color*$current_branch$no_star$no_color$2"
    else
        echo "$local_branch$1$no_color$2"
    fi
}

# Gets information about an issue number from GitHub's API
function getGitHubDesc {
    issue_number=$1
    user_token=$2
    branch_name=$3
    # Use curl to get the issue's information
    issue_json="$(curl -s --include https://api.github.com/repos/$repo_owner/$repo_name/issues/$issue_number?access_token=$user_token)"

    # grep the contents for the title line
    set +e
    title_line=`echo "$issue_json" | grep \"title\":\ \"`
    grep_code=$?
    set -e

    # If grep couldn't find the title line, return the original text
    if [ $grep_code -ne 0 ]; then
        echo "$branch_nane"
    else
        issue_title=`echo "$title_line" | grep '^\ \{1,\}\"title\":\ \"' | sed 's/^ *\"title\": \"//' | sed 's/\",$//'`
        echo "$issue_title" > "$git_dir/issues/$issue_number"
        colorBranchData "$branch_name" ": (\"$issue_title\")"
    fi

    # Capture rate limit remaining count
    rate_limit_remaining=`echo "$issue_json" | grep '^X-RateLimit-Remaining'` || true

    # Do extra stuff when verbose is enabled
    if $verbose ; then
        if [ $grep_code -eq 0 ]; then
            [[ "$fetched_issues" == "" ]] && fetched_issues="$issue_number" || fetched_issues="$fetched_issues, $issue_number"
        else
            [[ "$unknown_issues" == "" ]] && unknown_issues="$issue_number" || unknown_issues="$unknown_issues, $issue_number"
        fi
    fi
}

# Finds an issue's description
function getIssueDesc {
    if $use_cache ; then
        if [ -s "$git_dir/issues/$1" ]; then
            desc=`cat "$git_dir/issues/$1"`
            colorBranchData "$3" " :(\"$desc\")"
            # Do extra stuff when verbose is enabled
            if $verbose ; then
                [[ "$cached_issues" == "" ]] && cached_issues="$issue_number" || cached_issues="$cached_issues, $issue_number"
            fi
        else
            getGitHubDesc "$1" "$2" "$3"
        fi
    else
        getGitHubDesc "$1" "$2" "$3"
    fi
}

# Get .git directory, or exit on failure
git_dir=`git rev-parse --git-dir` || exit

# Check to see if the description cache exists, create it if it doesn't
[[ -d "$git_dir/issues" ]] || mkdir "$git_dir/issues"

# Clean out old cached descriptions
if $clear_cache ; then
    find "$git_dir/issues" -type f -exec rm {} \;
else
    find "$git_dir/issues" -type f -mtime +2 -exec rm {} \;
fi

# See if there are any remote URLs for GitHub
set +e
remote_url=`git config --list | grep remote | grep url | grep github | head`
grep_code=$?
set -e

# Error out with message to use if no GitHub remote URLs found
if [ $grep_code -ne 0 ]; then
    >&2 echo "Current repository does not appear to have an associated GitHub remote"
    >&2 echo "A GitHub remote is required for fetching GitHub Issues information"
    exit 1
fi

# Clean and split the remote URL
clean_repo=`echo "$remote_url" | sed 's/.\{1,\}github\.com[\\\/:]//g' | sed 's/\.git//g'`
repo_owner=`echo "$clean_repo" | sed 's/[\\\/].\{0,\}//g'`
repo_name=`echo "$clean_repo" | sed 's/[^\\\/]\{0,\}[\\\/]//g'`

# Get the user's GitHub access token
if [ "$user_token" == "" ]; then
    # The "|| true" keeps `git config` from erroring out this script
    # when the setting doesn't exist; there's specific handling for
    # empty token values below.
    user_token=`git config --get github.access-token` || true
fi

# Error out with message to user if no access token was found
if [ "$user_token" == "" ]; then
    >&2 echo "No GitHub access token has been specified."
    >&2 echo "Please create one with repo access and put it in your"
    >&2 echo "personal git config file at github.access-token"
    exit 1
fi

# Get the current branches
if $all_branches ; then
    branches=`git branch -a`
else
    branches=`git branch`
fi

# Loop through all branches
for branch in $branches; do
    # This command will fail if the current branch doesn't match the
    # expected format
    set +e
    temp=`echo "$branch" | grep "[0-9]\{1,\}$"`
    grep_code=$?
    set -e

    # Just output the branch name if it doesn't end with numbers
    if [ $grep_code -ne 0 ]; then
        colorBranchData "$branch" ""
    else
        # Split out numbers
        issue_number=`echo "$branch" | sed 's/[^[:digit:]]*\([[:digit:]]\{1,\}$\)/\\1/'`
        getIssueDesc "$issue_number" "$user_token" "$branch"
    fi
done

if $verbose ; then
    echo ""
    [[ "$rate_limit_remaining" == "" ]] && echo "GitHub API Status: API Not Used" || echo "GitHub API Status: $rate_limit_remaining"
    echo ""
    echo "Issue results from:"
    [[ "$cached_issues"  == "" ]] && echo "        Cache : None" || echo "        Cache : $cached_issues"
    [[ "$fetched_issues" == "" ]] && echo "API-Requested : None" || echo "API-Requested : $fetched_issues"
    [[ "$unknown_issues" == "" ]] && echo "  API-Unknown : None" || echo "  API-Unknown : $unknown_issues"
fi