patch 9.0.1786: Vim9: need instanceof() function
Problem: Vim9: need instanceof() function
Solution: Implement instanceof() builtin
Implemented in the same form as Python's isinstance because it allows
for checking multiple class types at the same time.
closes: #12867
Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: LemonBoy <thatlemon@gmail.com>
diff --git a/src/testdir/test_vim9_class.vim b/src/testdir/test_vim9_class.vim
index 7e33c6d..a650cc2 100644
--- a/src/testdir/test_vim9_class.vim
+++ b/src/testdir/test_vim9_class.vim
@@ -2367,6 +2367,39 @@
v9.CheckScriptSuccess(lines)
enddef
+def Test_instanceof()
+ var lines =<< trim END
+ vim9script
+
+ class Base1
+ endclass
+
+ class Base2 extends Base1
+ endclass
+
+ interface Intf1
+ endinterface
+
+ class Mix1 implements Intf1
+ endclass
+
+ class Base3 extends Mix1
+ endclass
+
+ var b1 = Base1.new()
+ var b2 = Base2.new()
+ var b3 = Base3.new()
+
+ assert_true(instanceof(b1, Base1))
+ assert_true(instanceof(b2, Base1))
+ assert_false(instanceof(b1, Base2))
+ assert_true(instanceof(b3, Mix1))
+ assert_false(instanceof(b3, []))
+ assert_true(instanceof(b3, [Base1, Base2, Intf1]))
+ END
+ v9.CheckScriptSuccess(lines)
+enddef
+
" Test for calling a method in the parent class that is extended partially.
" This used to fail with the 'E118: Too many arguments for function: Text' error
" message (Github issue #12524).