Strip comments and whitespace from javascript resources

third_party/closure_compiler/js_minify.py

+#!/usr/bin/python
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+''' Javascript minifier using the closure compiler
+
+This minifier strips spaces and comments out of Javascript using the closure
+compiler. It takes the original Javascript on standard input, and outputs
+the minified output on standard output.
+
+Any errors or other messages from the compiler are output on standard error.
+'''
+
+import argparse
+import sys
+import tempfile
+from compile2 import Checker

[Dan Beam, 2016/07/28 16:27:05]

nit: \n\n between top-level

[aberent, 2016/08/02 11:43:29]

Done.

+
+def Minify(source):
+  parser = argparse.ArgumentParser()
+  parser.add_argument("-c", "--closure_args", nargs=argparse.ZERO_OR_MORE,
+                      help="Arguments passed directly to the Closure compiler")
+  args = parser.parse_args()
+  closure_args = args.closure_args + ['compilation_level=WHITESPACE_ONLY']
+  with tempfile.NamedTemporaryFile(suffix='.js') as t1, \
+       tempfile.NamedTemporaryFile(suffix='.js') as t2:

[Dan Beam, 2016/07/28 16:27:05]

how do these get deleted?  should you be specifying delete=True?

[aberent, 2016/08/02 11:43:29]

No, it is the default, as you might expect, for temporary files.

+    t1.write(source)
+    t1.seek(0)
+    checker = Checker()
+    (compile_error, compile_stderr) = checker.check(
+        [t1.name], out_file=t2.name, closure_args=closure_args)
+    if compile_error:
+      print compile_stderr
+    t2.seek(0)
+    result = t2.read()
+    return result
+
+
+if __name__ == '__main__':
+  orig_stdout = sys.stdout
+  result = ''
+  try:
+    sys.stdout = sys.stderr
+    result = Minify(sys.stdin.read())
+  finally:
+    sys.stdout = orig_stdout
+    print result