test: Add unittest spec for option.c (#5289)

Move typedef expand_T to types.h for tests
Fix lint error for old style comments

Describe 'check_ff_value' valid values as an initial test.

Fix 'get_sts_value' comment inaccuracy and add unit test for it

1 files changed, 51 insertions, 0 deletions

diff --git a/test/unit/option_spec.lua b/test/unit/option_spec.lua
new file mode 100644
index 0000000000..8bab0194a2
--- /dev/null
+++ b/test/unit/option_spec.lua
@@ -0,0 +1,51 @@
+local helpers = require("test.unit.helpers")
+
+local to_cstr = helpers.to_cstr
+local eq      = helpers.eq
+
+local option = helpers.cimport("./src/nvim/option.h")
+local globals = helpers.cimport("./src/nvim/globals.h")
+
+local check_ff_value = function(ff)
+  return option.check_ff_value(to_cstr(ff))
+end
+
+describe('check_ff_value', function()
+
+  it('views empty string as valid', function()
+    eq(1, check_ff_value(""))
+  end)
+
+  it('views "unix", "dos" and "mac" as valid', function()
+    eq(1, check_ff_value("unix"))
+    eq(1, check_ff_value("dos"))
+    eq(1, check_ff_value("mac"))
+  end)
+
+  it('views "foo" as invalid', function()
+    eq(0, check_ff_value("foo"))
+  end)
+end)
+
+describe('get_sts_value', function()
+  it([[returns 'softtabstop' when it is non-negative]], function()
+    globals.curbuf.b_p_sts = 5
+    eq(5, option.get_sts_value())
+
+    globals.curbuf.b_p_sts = 0
+    eq(0, option.get_sts_value())
+  end)
+
+  it([[returns "effective shiftwidth" when 'softtabstop' is negative]], function()
+    local shiftwidth = 2
+    globals.curbuf.b_p_sw = shiftwidth
+    local tabstop = 5
+    globals.curbuf.b_p_ts = tabstop
+    globals.curbuf.b_p_sts = -2
+    eq(shiftwidth, option.get_sts_value())
+
+    shiftwidth = 0
+    globals.curbuf.b_p_sw = shiftwidth
+    eq(tabstop, option.get_sts_value())
+  end)
+end)