Simplify shell.getCommand() method signature

lib/shell.coffee

@@ -15,8 +15,9 @@ limitations under the License.
 ###
 
 child_process = require('child_process')
-_ = require('lodash')
 os = require('os')
+Promise = require('bluebird')
+_ = require('lodash')
 rindle = require('rindle')
 
 ###*
@@ -51,15 +52,14 @@ exports.getSubShellCommand = (command) ->
 # stdin is inherited from the parent process.
 #
 # @param {String} command - command
-# @param {Object} [options] - options
-# @param {String} [options.cwd] - current working directory
+# @param {String} cwd - current working directory
 # @returns {Promise}
 #
 # @example
 # shell.runCommand('echo hello').then ->
 # 	console.log('Done!')
 ###
-exports.runCommand = (command, options = {}) ->
+exports.runCommand = Promise.method (command, cwd) ->
 	env = {}
 
 	if os.platform() is 'win32'
@@ -77,7 +77,7 @@ exports.runCommand = (command, options = {}) ->
 	spawn = child_process.spawn subShellCommand.program, subShellCommand.args,
 		stdio: 'inherit'
 		env: _.merge(env, process.env)
-		cwd: options.cwd
+		cwd: cwd
 
 		# This is an internal undocumented option that causes
 		# spawn to execute multiple word commands correctly

tests/shell.spec.coffee

@@ -60,7 +60,7 @@ describe 'Shell:', ->
 				@childProcessSpawnStub.restore()
 
 			it 'should be rejected with an error', ->
-				promise = shell.runCommand('echo foo')
+				promise = shell.runCommand('echo foo', '.')
 				m.chai.expect(promise).to.be.rejectedWith('spawn error')
 
 		describe 'given a spawn that closes with an error code', ->
@@ -79,7 +79,7 @@ describe 'Shell:', ->
 				@childProcessSpawnStub.restore()
 
 			it 'should be rejected with an error', ->
-				promise = shell.runCommand('echo foo')
+				promise = shell.runCommand('echo foo', '.')
 				m.chai.expect(promise).to.be.rejectedWith('Child process exited with code 1')
 
 		describe 'given a spawn that closes with a zero code', ->
@@ -98,7 +98,7 @@ describe 'Shell:', ->
 				@childProcessSpawnStub.restore()
 
 			it 'should be resolved', ->
-				promise = shell.runCommand('echo foo')
+				promise = shell.runCommand('echo foo', '.')
 				m.chai.expect(promise).to.eventually.be.undefined
 
 			describe 'given windows', ->
@@ -111,7 +111,7 @@ describe 'Shell:', ->
 					@osPlatformStub.restore()
 
 				it 'should call spawn with the correct arguments', ->
-					shell.runCommand('echo foo')
+					shell.runCommand('echo foo', '.')
 					args = @childProcessSpawnStub.firstCall.args
 					m.chai.expect(args[0]).to.equal('cmd.exe')
 					m.chai.expect(args[1]).to.deep.equal([ '/s', '/c', 'echo foo' ])