git-fuzzy

#!/usr/bin/env node

var spawn = require("child_process").spawn,
    path  = require("path"),
    fuzzy = require("fuzzy");

var handleError = function(exitCode) {
    if (exitCode !== 0) {
        console.error("fatal: git-fuzzy execution error.");
        process.exit(exitCode);
    }
};

//Runs a command as a child process.
//If a callback is supplied, it will be invoked with the
//child process's stdout once the child process terminates.
//If no callback is supplied, the child process will use our
//process's stderr/stdout (preserving colors, if applicable.)
var run = function(command, arguments, callback) {

    var spawnOptions = callback ? {} : { stdio: "inherit" },
                  ps = spawn(command, arguments, spawnOptions);

    if (callback) {

        var stderr = "",
            stdout = "";

        ps.stdout.on("data", function(data) {
          stdout += data;
        });

        ps.stderr.on("data", function(data) {
          stderr += data;
        });

        ps.on("close", function(exitCode) {
            if (exitCode !== 0) {
                if (stderr) {
                    process.stderr.write(stderr);
                }
                handleError(exitCode);
            } else {
                callback(stdout.trim());
            }
        });

    } else {

        ps.on("close", handleError);

    }

};

if (process.argv.length < 3) {
    console.error("usage: git fuzzy <command> [<args>]");
    console.error("git-fuzzy will assume the last argument should fuzzy-match a filename that appears in the output of \"git status\".");
    process.exit(1);
}

var git_args = process.argv.slice(2, -1),
    last_arg = process.argv.slice(-1).toString();

//If a standalone Git command was specified, or if the last argument looks like a Git argument rather than a filename, just fall through to Git.
if (process.argv.length === 3 || last_arg.charAt(0) === "-") {

    run("git", process.argv.slice(2));

//Otherwise, assume the last argument is a fuzzy filename.
} else {

    run("git", ["status", "--porcelain"], function(status) {

        var git_status_lines = status.trim().split(/\n/);

        if (git_status_lines.length === 0) {
            console.error("fatal: nothing to match against; git-fuzzy only works when the working directory isn't clean.");
            process.exit(1);
        }

        var haystack = []; //A list of strings to fuzzy match against

        for (var i = 0; i < git_status_lines.length; i++) {
            var line = git_status_lines[i].trim();
            line = line.substring(2).trim(); //Strip the leading status flag and separator
            var tokens = line.split(" -> "); //Split by arrow in case something got renamed, but wrap in an array in all cases
            haystack = haystack.concat(tokens);
        }

        var matches = fuzzy.filter(last_arg, haystack).map(function(el) { return el.string; });

        if (matches.length === 0) {
            console.error("fatal: no matches");
            process.exit(1);
        } else if (matches.length > 1) {
            console.error("fatal: more than one match; please be more specific");
            console.error("matches:");
            for (var j = 0; j < matches.length; j++) {
                console.error("\t" + matches[j]);
            }
            process.exit(1);
        } else {
            run("git", ["rev-parse", "--show-toplevel"], function(git_root) {
                run("git", [].concat(git_args, path.join(git_root, matches[0])));
            });
        }

    });

}