eval: Make assert_true and assert_false accept v:true and v:false

2 files changed, 25 insertions, 4 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 22a12d353a..63fd392a3a 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -7587,16 +7587,20 @@ static void f_assert_equal(typval_T *argvars, typval_T *rettv)
 }
 
 // Common for assert_true() and assert_false().
-static void assert_bool(typval_T *argvars, bool isTrue)
+static void assert_bool(typval_T *argvars, bool is_true)
 {
   int error = (int)false;
   garray_T ga;
 
-  if (argvars[0].v_type != VAR_NUMBER ||
-      (get_tv_number_chk(&argvars[0], &error) == 0) == isTrue || error) {
+  if ((argvars[0].v_type != VAR_NUMBER ||
+       (get_tv_number_chk(&argvars[0], &error) == 0) == is_true || error)
+      && (argvars[0].v_type != VAR_SPECIAL
+          || argvars[0].vval.v_special != (is_true
+                                           ?kSpecialVarTrue
+                                           :kSpecialVarFalse))) {
     prepare_assert_error(&ga);
     fill_assert_error(&ga, &argvars[1],
-                      (char_u *)(isTrue ? "True" : "False"),
+                      (char_u *)(is_true ? "True" : "False"),
                       NULL, &argvars[0]);
     assert_error(&ga);
     ga_clear(&ga);
diff --git a/test/functional/eval/special_vars_spec.lua b/test/functional/eval/special_vars_spec.lua
index b5c65d23d9..7539261d49 100644
--- a/test/functional/eval/special_vars_spec.lua
+++ b/test/functional/eval/special_vars_spec.lua
@@ -151,4 +151,21 @@ describe('Special values', function()
     eq('Vim(echo):E15: Cannot index a special value', exc_exec('echo v:false[0]'))
     eq('Vim(echo):E15: Cannot index a special value', exc_exec('echo v:null[0]'))
   end)
+
+  it('is accepted by assert_true and assert_false', function()
+    funcs.assert_false(false)
+    funcs.assert_false(true)
+    eval('assert_false(v:null)')
+
+    funcs.assert_true(false)
+    funcs.assert_true(true)
+    eval('assert_true(v:null)')
+
+    eq({
+      'Expected False but got v:true',
+      'Expected False but got v:null',
+      'Expected True but got v:false',
+      'Expected True but got v:null',
+    }, meths.get_vvar('errors'))
+  end)
 end)