vim-patch:8.2.1632: not checking the context of test_fails()

Problem:    Not checking the context of test_fails().
Solution:   Add the line number and context arguments.  Give error if
            assert_fails() argument types are wrong.

44d6652d56

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/testdir/test_assert.vim

@@ -255,6 +255,20 @@ func Test_assert_fail_fails()
     let exp = v:exception
   endtry
   call assert_match("E856: assert_fails() second argument", exp)
+
+  try
+    call assert_equal(1, assert_fails('xxx', 'E492', '', 'burp'))
+  catch
+    let exp = v:exception
+  endtry
+  call assert_match("E1115: assert_fails() fourth argument must be a number", exp)
+
+  try
+    call assert_equal(1, assert_fails('xxx', 'E492', '', 54, 123))
+  catch
+    let exp = v:exception
+  endtry
+  call assert_match("E1116: assert_fails() fifth argument must be a string", exp)
 endfunc
 
 func Test_assert_fails_in_try_block()

src/nvim/testing.c

@@ -14,6 +14,12 @@
 # include "testing.c.generated.h"
 #endif
 
+static char e_assert_fails_second_arg[]
+  = N_("E856: assert_fails() second argument must be a string or a list with one or two strings");
+static char e_assert_fails_fourth_argument[]
+  = N_("E1115: assert_fails() fourth argument must be a number");
+static char e_assert_fails_fifth_argument[]
+  = N_("E1116: assert_fails() fifth argument must be a string");
 static char e_calling_test_garbagecollect_now_while_v_testing_is_not_set[]
   = N_("E1142: Calling test_garbagecollect_now() while v:testing is not set");
 
@@ -480,7 +486,7 @@ void f_assert_fails(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   garray_T ga;
   int save_trylevel = trylevel;
   const int called_emsg_before = called_emsg;
-  bool wrong_arg = false;
+  char *wrong_arg_msg = NULL;
 
   // trylevel must be zero for a ":throw" command to be considered failed
   trylevel = 0;
@@ -509,7 +515,7 @@ void f_assert_fails(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     } else if (argvars[1].v_type == VAR_LIST) {
       const list_T *const list = argvars[1].vval.v_list;
       if (list == NULL || tv_list_len(list) < 1 || tv_list_len(list) > 2) {
-        wrong_arg = true;
+        wrong_arg_msg = e_assert_fails_second_arg;
         goto theend;
       }
       const typval_T *tv = TV_LIST_ITEM_TV(tv_list_first(list));
@@ -525,25 +531,32 @@ void f_assert_fails(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
         }
       }
     } else {
-      wrong_arg = true;
+      wrong_arg_msg = e_assert_fails_second_arg;
       goto theend;
     }
 
     if (!error_found && argvars[2].v_type != VAR_UNKNOWN
-        && argvars[3].v_type == VAR_NUMBER) {
+        && argvars[3].v_type != VAR_UNKNOWN) {
-      if (argvars[3].vval.v_number >= 0
+      if (argvars[3].v_type != VAR_NUMBER) {
+        wrong_arg_msg = e_assert_fails_fourth_argument;
+        goto theend;
+      } else if (argvars[3].vval.v_number >= 0
                  && argvars[3].vval.v_number != emsg_assert_fails_lnum) {
         error_found = true;
         error_found_index = 3;
       }
-      if (!error_found && argvars[4].v_type == VAR_STRING
+      if (!error_found && argvars[4].v_type != VAR_UNKNOWN) {
-          && argvars[4].vval.v_string != NULL
+        if (argvars[4].v_type != VAR_STRING) {
+          wrong_arg_msg = e_assert_fails_fifth_argument;
+          goto theend;
+        } else if (argvars[4].vval.v_string != NULL
                    && !pattern_match(argvars[4].vval.v_string,
                                      emsg_assert_fails_context, false)) {
           error_found = true;
           error_found_index = 4;
         }
       }
+    }
 
     if (error_found) {
       typval_T actual_tv;
@@ -576,9 +589,8 @@ theend:
   emsg_assert_fails_used = false;
   XFREE_CLEAR(emsg_assert_fails_msg);
   set_vim_var_string(VV_ERRMSG, NULL, 0);
-  if (wrong_arg) {
+  if (wrong_arg_msg != NULL) {
-    emsg(_(
+    emsg(_(wrong_arg_msg));
-          "E856: assert_fails() second argument must be a string or a list with one or two strings"));
   }
 }