Refactor compile_js.gypi to support script_args and closure_args

third_party/closure_compiler/compile_js.gypi

 # Copyright 2014 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.
 {
   'type': 'none',
   'variables': {
     'CLOSURE_DIR': '<(DEPTH)/third_party/closure_compiler',
   },
   'actions': [
     {
       # This action optionally takes these arguments:
       # - depends: scripts that the source file depends on being included already
       # - externs: files that describe globals used by |source|
       'action_name': 'compile_js',
       'variables': {
-        'source_file': '<(_target_name).js',
+        'source_files': ['<(_target_name).js'],
         'out_file': '<(SHARED_INTERMEDIATE_DIR)/closure/<!(python <(CLOSURE_DIR)/build/outputs.py <@(source_file))',
         'externs%': [],
         'depends%': [],
+        'script_args': [],
+        'closure_args': [
+          '--accept_const_keyword',

[Theresa, 2015/05/28 23:12:18]

Would it make more sense to keep these in compile.py and just make this extra
closure_args passed in by client .gypi files. Or should the
polymer_extra_annotations and common_jscomp_errors move here?

[Dan Beam, 2015/05/28 23:15:11]

tbreisacher@ & jlklein@: wdyt?

[Dan Beam, 2015/05/28 23:23:31]

I think we should put them here if possible.  the only thing we might want to
keep inside (or here with a note) is --summary_detail_level=3 which compile.py
depends on for output parsing.

For instance, I'd think we'd change

  'script_args': ['--strict']

to

  'closure_args': [
    '--jscomp_error=reportUnknownTypes',
    '--jscomp_error=duplicate',
    '--jscomp_error=misplacedTypeAnnotation',
  ],

this allows callers to better understand what's going on and not accidentally
have their args overridden in some other place in the code.

+          '--language_in=ECMASCRIPT5_STRICT',
+          '--summary_detail_level=3',
+          '--compilation_level=SIMPLE_OPTIMIZATIONS',
+          '--source_map_format=V3',
+          '--polymer_pass',
+        ],
       },
       'inputs': [
         'compile_js.gypi',
         '<(CLOSURE_DIR)/compile.py',
         '<(CLOSURE_DIR)/processor.py',
         '<(CLOSURE_DIR)/build/inputs.py',
         '<(CLOSURE_DIR)/build/outputs.py',
         '<(CLOSURE_DIR)/compiler/compiler.jar',
         '<(CLOSURE_DIR)/runner/runner.jar',
         '<!@(python <(CLOSURE_DIR)/build/inputs.py <(source_file) -d <@(depends) -e <@(externs))',
       ],
       'outputs': [
         '<(out_file)',
       ],
       'action': [
         'python',
         '<(CLOSURE_DIR)/compile.py',
-        '<(source_file)',
+        '<(source_files)',
+        '<@(script_args)',
         '--depends', '<@(depends)',
         '--externs', '<@(externs)',
         '--out_file', '<(out_file)',
+        '<@(closure_args)',
         # Add '--verbose' for make glorious log spam of Closure compiler.
       ],
       'message': 'Compiling <(source_file)',
     }
   ],
 }