gcc

This module is being deprecated in favor of closurecompiler, and will be eventually unpublished. Please migrate.

Node wrapper for Google Closure Compiler.

$3

GCC upholds the Semantic Versioning Specification.

Installation

``
npm install gcc
`

Usage

`js
var compiler = require('gcc');
var source = ['file.js', 'file2.js'];
var destination = 'result.js';
var options = { compilation_level: 'WHITESPACE_ONLY' };
var callback = function (error, stdout, stderr) {
if (error) {
console.error(error);
} else {
console.log('Compiled size: ' + stdout.length + 'bytes');
}
};

compiler.compile(source, destination, options, callback);
`

API

Assuming:

`js
var compiler = require('gcc');
`

$3

String specifying java command. Default: java

If java is not exposed globally in system PATH, set the destination to it here.

$3

Options for closure compiler that will be used in every compile() call unless overridden by options
argument. Contains:

`js
{
compilation_level: 'SIMPLE_OPTIMIZATIONS'
}
`

$3

Function that does the compiling. Arguments:

`js
compiler.compile(source [, destination ] [, options ] [, callback ]);
`

- source Mixed : Path, or an array of paths to JavaScript files that should be concatenated and minified.
- destination String : When specified, output will be saved to this path.
- options Object : Object with Closure Compiler options. Extends compiler.defaults.
- callback Function : When specified, will be executed at the end of the compiling process. Accepts 3 arguments:
error which is null when no errors occurred, stdout containing the minified code, and stderr containing
the error output.

#### Return

Returns the compiling process with stdout and stderr streams.

Examples

Compile example.js into example.min.js with WHITESPACE_ONLY compilation level.

`js
compiler.compile('example.js', 'example.min.js', { compilation_level: 'WHITESPACE_ONLY' });
`

Compile example1.js and example2.js with default options, and handle the output in callback.

`js
compiler.compile(['example1.js', 'example2.js'], function (error, stdout, stderr) {
if (error) {
console.log(error);
} else {
console.log('Minified size: ' + stdout.length + 'bytes');
}
});
`

Compile example1.js and example2.js with custom options, and handle the compiling process manually.

`js
var compiling = compiler.compile(['example1.js', 'example2.js'], { compilation_level: 'WHITESPACE_ONLY' });

compiling.stdout.on('data', function (data) {
console.log('stdout: ' + data);
});

compiling.stderr.on('data', function (data) {
console.log('stderr: ' + data);
});

compiling.on('close', function (code) {
console.log('Compiling process has finished with exit code: ' + code);
});
`

Closure Compiler options

All options are passed as keys in an options object.

If an option is a flag with no input value, pass true as an option value:

`js
compiler.compile('example.js', 'result.js', {
debug: true
});
`

If an option accepts multiple values, pass them as an array to option value:

`js
compiler.compile('example.js', 'result.js', {
compilation_level: 'ADVANCED_OPTIMIZATIONS',
externs: [
'jquery.js',
'underscore.js'
]
});
`

---

$3

- WHITESPACE_ONLY : Removes comments, line breaks, unnecessary spaces, and other whitespace.
- SIMPLE_OPTIMIZATIONS : ^ plus shortens local variables, function names, and function parameters.
- ADVANCED_OPTIMIZATIONS : ^ but also for global variables, function names, and function parameters.

For more specific explanation, visit the Closure Compiler Compilation Levels documentation.

---

#### Rest of the Closure Compiler options as defined in --help

Note: Option js_output_file is ignored because when specified, compiler binary doesn't return stdout/err, but
only writes to the file which breaks callback arguments. Use the compiler() destination argument instead please. The
destination file is saved with fs writing stream consuming the stdout.

`
--accept_const_keyword : Allows usage of const keyword.
--angular_pass : Generate $inject properties for
AngularJS for functions annotated
with @ngInject
--charset VAL : Input and output charset for all
files. By default, we accept UTF-8 as
input and output US_ASCII
--closure_entry_point VAL : Entry points to the program. Must be
goog.provide'd symbols. Any goog.provi
de'd symbols that are not a transitive
dependency of the entry points will
be removed. Files without goog.provide
s, and their dependencies, will
always be left in. If any entry
points are specified, then the
manage_closure_dependencies option
will be set to true and all files
will be sorted in dependency order.
--common_js_entry_module VAL : Root of your common JS dependency
hierarchy. Your main script.
--common_js_module_path_prefix VAL : Path prefix to be removed from
CommonJS module names.
--compilation_level [WHITESPACE_ONLY : Specifies the compilation level to
| SIMPLE_OPTIMIZATIONS | ADVANCED_OPTI : use. Options: WHITESPACE_ONLY,
MIZATIONS] : SIMPLE_OPTIMIZATIONS, ADVANCED_OPTIMIZ
ATIONS
--create_name_map_files : If true, variable renaming and
property renaming map files will be
produced as {binary name}_vars_map.out
and {binary name}_props_map.out. Note
that this flag cannot be used in
conjunction with either variableMapOut
putFile or property_map_output_file
--create_source_map VAL : If specified, a source map file
mapping the generated source files
back to the original source file will
be output to the specified path. The
%outname% placeholder will expand to
the name of the output file that the
source map corresponds to.
--debug : Enable debugging options
--define (--D, -D) VAL : Override the value of a variable
annotated @define. The format is
[=], where is the
name of a @define variable and
is a boolean, number, or a single-quot
ed string that contains no single
quotes. If [=] is omitted, the
variable is marked true
--externs VAL : The file containing JavaScript
externs. You may specify multiple
--extra_annotation_name VAL : A whitelist of tag names in JSDoc.
You may specify multiple
--flagfile VAL : A file containing additional command-l
ine options.
--formatting [PRETTY_PRINT | PRINT_INP : Specifies which formatting options,
UT_DELIMITER | SINGLE_QUOTES] : if any, should be applied to the
output JS. Options: PRETTY_PRINT,
PRINT_INPUT_DELIMITER, SINGLE_QUOTES
--generate_exports : Generates export code for those
marked with @export
--help : Displays this message
--js VAL : The JavaScript filename. You may
specify multiple
--js_output_file VAL : Primary output filename. If not
specified, output is written to stdout
--jscomp_error VAL : Make the named class of warnings an
error. Options:accessControls,
ambiguousFunctionDecl, checkRegExp,
checkStructDictInheritance, checkTypes
, checkVars, const, constantProperty,
deprecated, duplicateMessage,
es5Strict, externsValidation,
fileoverviewTags, globalThis,
internetExplorerChecks, invalidCasts,
misplacedTypeAnnotation, missingProper
ties, missingReturn,nonStandardJsDocs,
reportUnknownTypes, suspiciousCode,
strictModuleDepCheck, typeInvalidation
, undefinedNames, undefinedVars,
unknownDefines, uselessCode, visibilit
y
--jscomp_off VAL : Turn off the named class of warnings.
Options:accessControls, ambiguousFunct
ionDecl, checkRegExp, checkStructDictI
nheritance, checkTypes, checkVars,
const, constantProperty, deprecated,
duplicateMessage, es5Strict, externsVa
lidation, fileoverviewTags, globalThis
, internetExplorerChecks, invalidCasts
, misplacedTypeAnnotation, missingProp
erties, missingReturn,nonStandardJsDoc
s, reportUnknownTypes, suspiciousCode,
strictModuleDepCheck, typeInvalidation
, undefinedNames, undefinedVars,
unknownDefines, uselessCode, visibilit
y
--jscomp_warning VAL : Make the named class of warnings a
normal warning. Options:accessControls
, ambiguousFunctionDecl, checkRegExp,
checkStructDictInheritance, checkTypes
, checkVars, const, constantProperty,
deprecated, duplicateMessage,
es5Strict, externsValidation,
fileoverviewTags, globalThis,
internetExplorerChecks, invalidCasts,
misplacedTypeAnnotation, missingProper
ties, missingReturn,nonStandardJsDocs,
reportUnknownTypes, suspiciousCode,
strictModuleDepCheck, typeInvalidation
, undefinedNames, undefinedVars,
unknownDefines, uselessCode, visibilit
y
--language_in VAL : Sets what language spec that input
sources conform. Options: ECMASCRIPT3
(default), ECMASCRIPT5, ECMASCRIPT5_ST
RICT
--logging_level VAL : The logging level (standard java.util.
logging.Level values) for Compiler
progress. Does not control errors or
warnings for the JavaScript code
under compilation
--manage_closure_dependencies : Automatically sort dependencies so
that a file that goog.provides symbol
X will always come before a file that
goog.requires symbol X. If an input
provides symbols, and those symbols
are never required, then that input
will not be included in the compilatio
n.
--module VAL : A JavaScript module specification.
The format is :[:[
,...][:]]]. Module names must be
unique. Each dep is the name of a
module that this module depends on.
Modules must be listed in dependency
order, and JS source files must be
listed in the corresponding order.
Where --module flags occur in
relation to --js flags is unimportant.
Provide the value 'auto' to trigger
module creation from CommonJSmodules.
--module_output_path_prefix VAL : Prefix for filenames of compiled JS
modules. .js will be
appended to this prefix. Directories
will be created as needed. Use with
--module
--module_wrapper VAL : An output wrapper for a JavaScript
module (optional). The format is
:. The module name
must correspond with a module
specified using --module. The wrapper
must contain %s as the code placeholde
r. The %basename% placeholder can
also be used to substitute the base
name of the module output file.
--only_closure_dependencies : Only include files in the transitive
dependency of the entry points
(specified by closure_entry_point).
Files that do not provide dependencies
will be removed. This supersedesmanage
_closure_dependencies
--output_manifest VAL : Prints out a list of all the files in
the compilation. If --manage_closure_d
ependencies is on, this will not
include files that got dropped
because they were not required. The
%outname% placeholder expands to the
JS output file. If you're using
modularization, using %outname% will
create a manifest for each module.
--output_module_dependencies VAL : Prints out a JSON file of dependencies
between modules.
--output_wrapper VAL : Interpolate output into this string
at the place denoted by the marker
token %output%. Use marker token
%output|jsstring% to do js string
escaping on the output.
--print_ast : Prints a dot file describing the
internal abstract syntax tree and
exits
--print_pass_graph : Prints a dot file describing the
passes that will get run and exits
--print_tree : Prints out the parse tree and exits
--process_closure_primitives : Processes built-ins from the Closure
library, such as goog.require(),
goog.provide(), and goog.exportSymbol(
)
--process_common_js_modules : Process CommonJS modules to a
concatenable form.
--process_jquery_primitives : Processes built-ins from the Jquery
library, such as jQuery.fn and
jQuery.extend()
--property_map_input_file VAL : File containing the serialized
version of the property renaming map
produced by a previous compilation
--property_map_output_file VAL : File where the serialized version of
the property renaming map produced
should be saved
--source_map_format [V1 | DEFAULT | : The source map format to produce.
V2 | V3] : Options: V1, V2, V3, DEFAULT. DEFAULT
produces V2.
--summary_detail_level N : Controls how detailed the compilation
summary is. Values: 0 (never print
summary), 1 (print summary only if
there are errors or warnings), 2
(print summary if the 'checkTypes'
diagnostic group is enabled, see
--jscomp_warning), 3 (always print
summary). The default level is 1
--third_party : Check source validity but do not
enforce Closure style rules and
conventions
--transform_amd_modules : Transform AMD to CommonJS modules.
--translations_file VAL : Source of translated messages.
Currently only supports XTB.
--translations_project VAL : Scopes all translations to the
specified project.When specified, we
will use different message ids so
that messages in different projects
can have different translations.
--use_only_custom_externs : Specifies whether the default externs
should be excluded
--use_types_for_optimization : Experimental: perform additional
optimizations based on available
information. Inaccurate type
annotations may result in incorrect
results.
--variable_map_input_file VAL : File containing the serialized
version of the variable renaming map
produced by a previous compilation
--variable_map_output_file VAL : File where the serialized version of
the variable renaming map produced
should be saved
--version : Prints the compiler version to stderr.
--warning_level [QUIET | DEFAULT | : Specifies the warning level to use.
VERBOSE] : Options: QUIET, DEFAULT, VERBOSE
--warnings_whitelist_file VAL : A file containing warnings to
suppress. Each line should be of the
form
:? escription>
``