patch 8.2.3844: Vim9: no type error if assigning func(number) to func(string)
Problem: Vim9: no type error if assigning a value with type func(number) to
a variable of type func(string).
Solution: Use check_type_maybe(): return MAYBE if a runtime type check is
useful. (issue #8492)
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index e1fe095..f7af299 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -2146,6 +2146,23 @@
CheckScriptFailure(lines, 'E704:')
enddef
+def Test_script_funcref_runtime_type_check()
+ var lines =<< trim END
+ vim9script
+ def FuncWithNumberArg(n: number)
+ enddef
+ def Test()
+ var Ref: func(string) = function(FuncWithNumberArg)
+ enddef
+ defcompile
+ END
+ # OK at compile time
+ CheckScriptSuccess(lines)
+
+ # Type check fails at runtime
+ CheckScriptFailure(lines + ['Test()'], 'E1012: Type mismatch; expected func(string) but got func(number)')
+enddef
+
def Test_inc_dec()
var lines =<< trim END
var nr = 7