[CS2] CLI: Test option parsing for current CLI (#4565)

* intermediate save

* add note saying where OptionParser is used in coffee command

* add some more work

* fix flatten functions

* refactor tests

* add basic test

* remove unused file

* compilation now hangs

* remove unnecessary changes

* add tests!!!

* clarify a test

src/command.coffee

@@ -61,10 +61,14 @@ notSources   = {}
 watchedDirs  = {}
 optionParser = null
 
+exports.buildCSOptionParser = buildCSOptionParser = ->
+  new optparse.OptionParser SWITCHES, BANNER
+
 # Run `coffee` by parsing passed options and determining what action to take.
 # Many flags cause us to divert before compiling anything. Flags passed after
 # `--` will be passed verbatim to your script as arguments in `process.argv`
 exports.run = ->
+  optionParser = buildCSOptionParser()
   parseOptions()
   # Make the REPL *CLI* use the global context so as to (a) be consistent with the
   # `node` REPL CLI and, therefore, (b) make packages that modify native prototypes
@@ -400,7 +404,6 @@ printTokens = (tokens) ->
 # Use the [OptionParser module](optparse.html) to extract all options from
 # `process.argv` that are specified in `SWITCHES`.
 parseOptions = ->
-  optionParser  = new optparse.OptionParser SWITCHES, BANNER
   o = opts      = optionParser.parse process.argv[2..]
   o.compile     or=  !!o.output
   o.run         = not (o.compile or o.print or o.map)
@@ -449,7 +452,7 @@ forkNode = ->
 # Print the `--help` usage message and exit. Deprecated switches are not
 # shown.
 usage = ->
-  printLine (new optparse.OptionParser SWITCHES, BANNER).help()
+  printLine optionParser.help()
 
 # Print the `--version` message and exit.
 version = ->

src/optparse.coffee

@@ -8,6 +8,9 @@
 #
 # The first non-option is considered to be the start of the file (and file
 # option) list, and all subsequent arguments are left unparsed.
+#
+# The `coffee` command uses an instance of **OptionParser** to parse its
+# command-line arguments in `src/command.coffee`.
 exports.OptionParser = class OptionParser
 
   # Initialize with a list of valid options, in the form:

test/argument-parsing.coffee

@@ -0,0 +1,73 @@
+{buildCSOptionParser} = require '../lib/coffeescript/command'
+
+optionParser = buildCSOptionParser()
+
+sameOptions = (opts1, opts2, msg) ->
+  ownKeys = Object.keys(opts1).sort()
+  otherKeys = Object.keys(opts2).sort()
+  arrayEq ownKeys, otherKeys, msg
+  for k in ownKeys
+    arrayEq opts1[k], opts2[k], msg
+  yes
+
+test "combined options are still split after initial file name", ->
+  argv = ['some-file.coffee', '-bc']
+  parsed = optionParser.parse argv
+  expected = arguments: ['some-file.coffee', '-b', '-c']
+  sameOptions parsed, expected
+
+  argv = ['some-file.litcoffee', '-bc']
+  parsed = optionParser.parse argv
+  expected = arguments: ['some-file.litcoffee', '-b', '-c']
+  sameOptions parsed, expected
+
+  argv = ['-c', 'some-file.coffee', '-bc']
+  parsed = optionParser.parse argv
+  expected =
+    compile: yes
+    arguments: ['some-file.coffee', '-b', '-c']
+  sameOptions parsed, expected
+
+  argv = ['-bc', 'some-file.coffee', '-bc']
+  parsed = optionParser.parse argv
+  expected =
+    bare: yes
+    compile: yes
+    arguments: ['some-file.coffee', '-b', '-c']
+  sameOptions parsed, expected
+
+test "combined options are not split after a '--'", ->
+  argv = ['--', '-bc']
+  parsed = optionParser.parse argv
+  expected = arguments: ['-bc']
+  sameOptions parsed, expected
+
+  argv = ['-bc', '--', '-bc']
+  parsed = optionParser.parse argv
+  expected =
+    bare: yes
+    compile: yes
+    arguments: ['-bc']
+  sameOptions parsed, expected
+
+test "options are not split after any '--'", ->
+  argv = ['--', '--', '-bc']
+  parsed = optionParser.parse argv
+  expected = arguments: ['--', '-bc']
+  sameOptions parsed, expected
+
+  argv = ['--', 'some-file.coffee', '--', 'arg']
+  parsed = optionParser.parse argv
+  expected = arguments: ['some-file.coffee', '--', 'arg']
+  sameOptions parsed, expected
+
+  argv = ['--', 'arg', 'some-file.coffee', '--', '-bc']
+  parsed = optionParser.parse argv
+  expected = arguments: ['arg', 'some-file.coffee', '--', '-bc']
+  sameOptions parsed, expected
+
+test "later '--' are removed", ->
+  argv = ['some-file.coffee', '--', '-bc']
+  parsed = optionParser.parse argv
+  expected = arguments: ['some-file.coffee', '-bc']
+  sameOptions parsed, expected