Wrapper that finds the latest UnityYAMLMerge installed on your Mac

yamlmerge-proxy.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# The MIT License (MIT)
# 
# Copyright (c) 2017 Adrian Stutz
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

#### Introduction ####
#
# Unity provides the UnityYAMLMerge merge tool to intelligently merge Unity's
# YAML-based text asset files.
# 
# The merge tool needs to be configured with your version control software and 
# they usually require an absolute path to the merge tool.
# However, many people have multiple versions of Unity installed and so the 
# path of the Unity installation and with it the the path to the merge tool can
# change at any time.
# 
# This script can be used as a proxy between your version control software
# and the merge tool installed with Unity. The script looks for the latest
# Unity installation on your system and then forwards the call to the
# merge tool.

import os.path
import re
import subprocess
import sys

# Bundle ID that will be looked up via Spotlight to find Unity installs
# (note that Unity 2017 still has the same bundle id)
UNITY_BUNDLE_ID = "com.unity3d.UnityEditor5.x"
# Regex to match Unity version from full version string, e.g. "Unity version 2017.1.0b7"
VERSION_RE = "(\d+)\.(\d+)\.(\d+)(\w)(\d+)"
# Sorting strength for release type letters in versions
RELEASE_LETTER_STRENGTH = { 'f': 1, 'p': 2, 'b': 3, 'a': 4 }
# Sub-path to the merge tool executable from the Unity.app bundle
MERGE_TOOL_PATH = "/Contents/Tools/UnityYAMLMerge"

# Parse a version string and return a list with the individual version numbers
def parse_version(version):
    match = re.search(VERSION_RE, version)
    if not match:
        print 'Version %s does not conform to Unity version format 0.0.0x0' % version
        sys.exit(1)
    
    parts = list(match.groups())
    
    # Convert to int, except fourth element wich is release type letter
    for i in range(len(parts)):
        if not parts[i] or i == 3: continue
        parts[i] = int(parts[i])
    
    if parts[3]:
        if not parts[3] in RELEASE_LETTER_STRENGTH:
            print 'Unknown release letter "%s" from "%s"' % (parts[3], version)
            sys.exit(1)
        parts[3] = RELEASE_LETTER_STRENGTH[parts[3]]
    else:
        parts[3] = RELEASE_LETTER_STRENGTH['f']
    
    return parts

def compare_versions(one, two):
    return cmp(parse_version(one["version"]), parse_version(two["version"]))

# Use spotlight to find Unity installations
command = "mdfind kMDItemCFBundleIdentifier = '%s'" % UNITY_BUNDLE_ID
data = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE).stdout.read()

# Validate installations
paths = filter(None, data.split("\n"))
installs = []
for path in paths:
    # Get and check the Unity version string
    command = "mdls -name kMDItemVersion -r '%s'" % path
    data = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE).stdout.read()
    
    match = re.search(VERSION_RE, data)
    if not match:
        print "WARNING: Could not parse Unity version string '%s' at path '%s'" % (data, path)
        continue
    
    # Unity < 5 didn't yet include the merge tool
    if int(match.group(1)) < 5:
        continue
    
    # Check if the tool exists at the expected path
    tool_path = path + MERGE_TOOL_PATH
    if not os.path.isfile(tool_path):
        print "WARNING: Unity installation '%s' does not contain merge tool at '%s'" % (path, tool_path)
        continue

    installs.append({
        "version": data,
        "path": tool_path
    })

if len(installs) == 0:
    print "ERROR: No Unity installation found"
    sys.exit(1)

# Use the merge tool from the newest Unity version
installs = sorted(installs, compare_versions)
path = installs[0]["path"]

# Wrap the merge tool, connecting our stdin, stdout and stderr
p = subprocess.Popen([path] + sys.argv[1:], stdin=sys.stdin, stdout=sys.stdout, stderr=sys.stderr)
p.wait()
sys.exit(p.returncode)