Replace all build and run scripts (#98)

To help with students working on different platforms, this change
replaces all the build and run scripts with a single script that
will have various platforms. This will now require students to have
python installed on their machines.

Usage:
  python build.py clean
  python build.py build
  python build.py rebuild
  python build.py run <class path> [args ...]

Closes #92
Closes #45

.travis.yml

@@ -11,6 +11,7 @@ os:
 
 
 script:
-  - ./clean.sh
-  - ./make.sh
-  - ./test.sh
+  - mkdir -p bin
+  - python build.py clean
+  - python build.py build
+  - python build.py run codeu.chat.TestRunner

build.py

@@ -0,0 +1,144 @@
+#!/usr/bin/python
+
+# Copyright 2017 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an 'AS IS' BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+###############################################################################
+# This build script is responsible for building and running all modules in
+# this project. The following commands are supported:
+#
+#   clean : Remove all files in the output directory. This will not remove the
+#           the output directory itself to allow the output directory to be
+#           a symlink.
+#
+#   build : Build the full project. This will build all java files found in any
+#           of the src directories.
+#
+#   rebuild : Call the clean and the build commands. For more information on
+#             CLEAN and BUILD see the above entries.
+#
+#   run <class path> [ arguments ... ] : Run the specified class. All arguments
+#                                        after the class path will be passed to
+#                                        the java class when it runs.
+###############################################################################
+
+
+import os
+import shutil
+import subprocess
+import sys
+
+
+CONFIG = {
+  'out' : 'bin',
+  'src' : [ 'src', 'test' ],
+  'libraries' : [
+    'third_party/junit4-4.11.jar',
+    'third_party/hamcrest-core-1.3.jar'
+  ],
+  'separators' : {
+    'nt' : ';',
+    'posix' : ':'
+  }
+}
+
+
+# CLEAN
+#
+# Remove all files from the build output directory.
+#
+def clean(config) :
+  out = config['out']
+
+  for entry in [ os.path.join(out, name) for name in os.listdir(out) ] :
+    if os.path.isdir(entry) :
+      shutil.rmtree(entry)
+    else :
+      os.remove(entry)
+
+  print('Clean PASSED')
+### def clean ###
+
+
+# BUILD
+#
+# Build the project defined by the config object. This will find all source
+# files in the source directories, link all specified libraries, and write
+# all output to the out directory.
+#
+def build(config) :
+  libraries = config['libraries']
+  out = config['out']
+  separator = config['separators'][os.name]
+  src = config['src']
+
+  # Find all the source files in the given source directories. Only allow java files
+  # because javac will fail if a non-java file is given.
+  src_files = [ ]
+  for src_path in src :
+    for root, dirs, files in os.walk(src_path) :
+      src_files += [ os.path.join(root, file) for file in files if file.endswith('.java') ]
+
+  # Take all the data from above and build a single command that can
+  # be ran to build the project.
+  command = [ ]
+  command += [ 'javac' ]
+  command += [ '-d', out ]
+  command += [ '-cp', separator.join([ out ] + libraries) ]
+  command += [ '-Xlint' ]
+  command += src_files
+
+  print('running : %s' % command)
+  print('Build %s' % ('PASSED' if subprocess.call(command) == 0 else 'FAILED'))
+### def build ###
+
+
+# RUN
+#
+# Run a class from within the project.
+#
+def run(config, start_class_path, arguments):
+  libraries = config['libraries']
+  out = config['out']
+  separator = config['separators'][os.name]
+
+  command = [ ]
+  command += [ 'java' ]
+  command += [ '-cp', separator.join([ out ] + libraries) ]
+  command += [ start_class_path ]
+  command += arguments
+
+  print('running : %s' % command)
+  print('Build %s' % ('PASSED' if subprocess.call(command) == 0 else 'FAILED'))
+### def run ###
+
+
+# MAIN
+def main(args) :
+  if 'clean' == args[0] :
+    clean(CONFIG)
+  elif 'build' == args[0] :
+    build(CONFIG)
+  elif 'rebuild' == args[0] :
+    clean(CONFIG)
+    build(CONFIG)
+  elif 'run' == args[0] :
+    run(CONFIG, args[1], args[2:])
+  else :
+    print('Unknown command "%s"' % args)
+
+
+if __name__ == '__main__':
+  # Remove the first argument as that will be the name of this file
+  main(sys.argv[1:])