patch 9.1.0080: unexpected error for modifying final list using +=
Problem: unexpected error for modifying final list using += operator
(Ernie Rael)
Solution: Allow List value modification of a final variable using +=
operator
(Yegappan Lakshmanan)
fixes: #13745
fixes: #13959
closes: #13962
Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index aef09c5..4414f55 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -3484,4 +3484,101 @@
v9.CheckScriptFailure(lines, 'E1407: Cannot use a Typealias as a variable or value')
enddef
+" Test for modifying a final variable using a compound operator
+def Test_final_var_modification_with_compound_op()
+ var lines =<< trim END
+ vim9script
+
+ final i: number = 1000
+ assert_fails('i += 2', 'E46: Cannot change read-only variable "i"')
+ assert_fails('i -= 2', 'E46: Cannot change read-only variable "i"')
+ assert_fails('i *= 2', 'E46: Cannot change read-only variable "i"')
+ assert_fails('i /= 2', 'E46: Cannot change read-only variable "i"')
+ assert_fails('i %= 2', 'E46: Cannot change read-only variable "i"')
+ assert_equal(1000, i)
+
+ final f: float = 1000.0
+ assert_fails('f += 2', 'E46: Cannot change read-only variable "f"')
+ assert_fails('f -= 2', 'E46: Cannot change read-only variable "f"')
+ assert_fails('f *= 2', 'E46: Cannot change read-only variable "f"')
+ assert_fails('f /= 2', 'E46: Cannot change read-only variable "f"')
+ assert_equal(1000.0, f)
+
+ final s: string = 'abc'
+ assert_fails('s ..= "y"', 'E46: Cannot change read-only variable "s"')
+ assert_equal('abc', s)
+ END
+ v9.CheckScriptSuccess(lines)
+enddef
+
+" Test for modifying a final variable with a List value
+def Test_final_var_with_list_value()
+ var lines =<< trim END
+ vim9script
+
+ final listA: list<string> = []
+ var listB = listA
+
+ listB->add('a')
+ assert_true(listA is listB)
+ assert_equal(['a'], listA)
+ assert_equal(['a'], listB)
+
+ listB += ['b']
+ assert_true(listA is listB)
+ assert_equal(['a', 'b'], listA)
+ assert_equal(['a', 'b'], listB)
+
+ listA->add('c')
+ assert_true(listA is listB)
+ assert_equal(['a', 'b', 'c'], listA)
+ assert_equal(['a', 'b', 'c'], listB)
+
+ listA += ['d']
+ assert_true(listA is listB)
+ assert_equal(['a', 'b', 'c', 'd'], listA)
+ assert_equal(['a', 'b', 'c', 'd'], listB)
+ END
+ v9.CheckScriptSuccess(lines)
+enddef
+
+" Test for modifying a final variable with a List value using "+=" from a legacy
+" function.
+func Test_final_var_with_list_value_legacy()
+ vim9cmd final g:TestVar = ['a']
+ vim9cmd g:TestVar += ['b']
+ call assert_equal(['a', 'b'], g:TestVar)
+endfunc
+
+" Test for modifying a final variable with a Blob value
+def Test_final_var_with_blob_value()
+ var lines =<< trim END
+ vim9script
+
+ final blobA: blob = 0z10
+ var blobB = blobA
+
+ blobB->add(32)
+ assert_true(blobA is blobB)
+ assert_equal(0z1020, blobA)
+ assert_equal(0z1020, blobB)
+
+ blobB += 0z30
+ assert_true(blobA is blobB)
+ assert_equal(0z102030, blobA)
+ assert_equal(0z102030, blobB)
+
+ blobA->add(64)
+ assert_true(blobA is blobB)
+ assert_equal(0z10203040, blobA)
+ assert_equal(0z10203040, blobB)
+
+ blobA += 0z50
+ assert_true(blobA is blobB)
+ assert_equal(0z1020304050, blobA)
+ assert_equal(0z1020304050, blobB)
+ END
+ v9.CheckScriptSuccess(lines)
+enddef
+
" vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker