Apply small refactor to unit tests

Redefine macro constants as enums in the ffi and import those in their
respective test modules.

test/unit/helpers.moon

@@ -3,24 +3,27 @@ ffi = require 'ffi'
 -- load neovim shared library
 libnvim = ffi.load './build/src/libnvim-test.so'
 
--- Luajit ffi parser only understands function signatures.
--- This helper function normalizes headers, passes to ffi and returns the
--- library pointer
+-- Luajit ffi parser doesn't understand preprocessor directives, so
+-- this helper function removes common directives before passing it the to ffi.
+-- It will return a pointer to the library table, emulating 'requires'
 cimport = (path) ->
-  -- Can't parse some of vim types, perhaps need to define those before
-  -- automatically importing to ffi
+  header_file = io.open path, 'rb'
 
-  -- header_file = io.open path, 'rb'
-  -- header = header_file\read '*a'
-  -- header_file.close!
-  -- header = string.gsub header, '#include[^\n]*\n', ''
-  -- header = string.gsub header, '#ifndef[^\n]*\n', ''
-  -- header = string.gsub header, '#define[^\n]*\n', ''
-  -- header = string.gsub header, '#endif[^\n]*\n', ''
-  -- ffi.cdef header
+  if not header_file
+    error "cannot find #{path}"
+
+  header = header_file\read '*a'
+  header_file.close!
+  header = string.gsub header, '#include[^\n]*\n', ''
+  header = string.gsub header, '#ifndef[^\n]*\n', ''
+  header = string.gsub header, '#define[^\n]*\n', ''
+  header = string.gsub header, '#endif[^\n]*\n', ''
+  ffi.cdef header
 
   return libnvim
 
+cimport './src/types.h'
+
 -- take a pointer to a C-allocated string and return an interned
 -- version while also freeing the memory
 internalize = (cdata) ->
@@ -32,4 +35,6 @@ return {
   internalize: internalize
   eq: (expected, actual) -> assert.are.same expected, actual
   ffi: ffi
+  lib: libnvim
+  cstr: ffi.typeof 'char[?]'
 }

test/unit/misc1.moon

@@ -1,13 +1,21 @@
-{:cimport, :internalize, :eq, :ffi} = require 'test.unit.helpers'
+{:cimport, :internalize, :eq, :ffi, :lib, :cstr} = require 'test.unit.helpers'
 
-misc1 = cimport './src/misc1.h'
-cstr = ffi.typeof 'char[?]'
+--misc1 = cimport './src/misc1.h'
 
--- TODO extract constants from vim.h
+-- remove these statements once 'cimport' is working properly for misc1.h
+misc1 = lib
+ffi.cdef [[
+enum FPC {
+  FPC_SAME = 1, FPC_DIFF = 2, FPC_NOTX = 4, FPC_DIFFX = 6, FPC_SAMEX = 7
+};
+int fullpathcmp(char_u *s1, char_u *s2, int checkname);
+]]
+
+-- import constants parsed by ffi
+{:FPC_SAME, :FPC_DIFF, :FPC_NOTX, :FPC_DIFFX, :FPC_SAMEX} = lib
 
 describe 'misc1 function', ->
   describe 'fullpathcmp', ->
-    ffi.cdef 'int fullpathcmp(char *s1, char *s2, int checkname);'
 
     fullpathcmp = (s1, s2, cn) ->
       s1 = cstr (string.len s1) + 1, s1
@@ -17,12 +25,6 @@ describe 'misc1 function', ->
     f1 = 'f1.o'
     f2 = 'f2.o'
 
-    FPC_SAME = 1
-    FPC_DIFF = 2
-    FPC_NOTX = 4
-    FPC_DIFFX = 6
-    FPC_SAMEX = 7
-
     before_each ->
       -- create the three files that will be used in this spec
       (io.open f1, 'w').close!

test/unit/os/fs.moon

@@ -1,16 +1,22 @@
-{:cimport, :internalize, :eq, :ffi} = require 'test.unit.helpers'
+{:cimport, :internalize, :eq, :ffi, :lib, :cstr} = require 'test.unit.helpers'
 require 'lfs'
 
-fs = cimport './src/fs.h'
-cstr = ffi.typeof 'char[?]'
+-- fs = cimport './src/os/os.h'
+-- remove these statements once 'cimport' is working properly for misc1.h
+fs = lib
+ffi.cdef [[
+enum OKFAIL {
+  OK = 1, FAIL = 0
+};
+int mch_dirname(char_u *buf, int len);
+]]
+
+-- import constants parsed by ffi
+{:OK, :FAIL} = lib
 
 describe 'fs function', ->
 
-  export OK = 1
-  export FAIL = 0
-
   describe 'mch_dirname', ->
-    ffi.cdef 'int mch_dirname(char *buf, int len);'
 
     mch_dirname = (buf, len) ->
       fs.mch_dirname buf, len