patch 8.2.1794: no falsy Coalescing operator
Problem: No falsy Coalescing operator.
Solution: Add the "??" operator. Fix mistake with function argument count.
diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index cfae760..1086534 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -42,6 +42,28 @@
call assert_false(has('patch-9.9.1'))
endfunc
+func Test_op_falsy()
+ call assert_equal(v:true, v:true ?? 456)
+ call assert_equal(123, 123 ?? 456)
+ call assert_equal('yes', 'yes' ?? 456)
+ call assert_equal(0z00, 0z00 ?? 456)
+ call assert_equal([1], [1] ?? 456)
+ call assert_equal(#{one: 1}, #{one: 1} ?? 456)
+ if has('float')
+ call assert_equal(0.1, 0.1 ?? 456)
+ endif
+
+ call assert_equal(456, v:false ?? 456)
+ call assert_equal(456, 0 ?? 456)
+ call assert_equal(456, '' ?? 456)
+ call assert_equal(456, 0z ?? 456)
+ call assert_equal(456, [] ?? 456)
+ call assert_equal(456, {} ?? 456)
+ if has('float')
+ call assert_equal(456, 0.0 ?? 456)
+ endif
+endfunc
+
func Test_dict()
let d = {'': 'empty', 'a': 'a', 0: 'zero'}
call assert_equal('empty', d[''])