Add environment module for getting environment info

spec/environment-spec.coffee

@@ -0,0 +1,27 @@
+child_process = require('child_process')
+{getShellEnv} = require("../src/environment")
+
+describe "Environment handling", ->
+  describe "when things are configured properly", ->
+    beforeEach ->
+      spyOn(child_process, "spawnSync").andReturn
+        stdout: """
+            FOO=BAR
+            TERM=xterm-something
+            PATH=/usr/bin:/bin:/usr/sbin:/sbin:/some/crazy/path/entry/that/should/not/exist
+          """
+
+    it "returns an object containing the information from the user's shell environment", ->
+      env = getShellEnv()
+
+      expect(env.FOO).toEqual "BAR"
+      expect(env.TERM).toEqual "xterm-something"
+      expect(env.PATH).toEqual "/usr/bin:/bin:/usr/sbin:/sbin:/some/crazy/path/entry/that/should/not/exist"
+
+  describe "when an error occurs", ->
+    beforeEach ->
+      spyOn(child_process, "spawnSync").andReturn
+        error: new Error
+
+    it "returns undefined", ->
+      expect(getShellEnv()).toBeUndefined()

src/environment.coffee

@@ -0,0 +1,41 @@
+child_process = require('child_process')
+os = require('os')
+
+# Gets a dump of the user's configured shell environment.
+#
+# Returns the output of the `env` command or `undefined` if there was an error.
+getRawShellEnv = ->
+  shell = process.env.SHELL ? "/bin/bash"
+
+  # The `-ilc` set of options was tested to work with the OS X v10.11
+  # default-installed versions of bash, zsh, sh, and ksh. It *does not*
+  # work with csh or tcsh. Given that bash and zsh should cover the
+  # vast majority of users and it gracefully falls back to prior behavior,
+  # this should be safe.
+  results = child_process.spawnSync shell, ["-ilc"], input: "env", encoding: "utf8"
+  return if results.error?
+  return unless results.stdout and results.stdout.length > 0
+
+  results.stdout
+
+module.exports =
+  # Gets the user's configured shell environment.
+  #
+  # Returns a copy of the user's shell enviroment.
+  getShellEnv: ->
+    shellEnvText = getRawShellEnv()
+    return unless shellEnvText?
+
+    env = {}
+
+    for line in shellEnvText.split(os.EOL)
+      if line.includes("=")
+        components = line.split("=")
+        if components.length is 2
+          env[components[0]] = components[1]
+        else
+          k = components.shift()
+          v = components.join("=")
+          env[k] = v
+
+    env