3 files changed, 65 insertions, 0 deletions

diff --git a/src/nvim/testdir/test_alot.vim b/src/nvim/testdir/test_alot.vim
index 036a4c0470..87c1cd2c58 100644
--- a/src/nvim/testdir/test_alot.vim
+++ b/src/nvim/testdir/test_alot.vim
@@ -4,6 +4,8 @@
 source test_assign.vim
 source test_cursor_func.vim
 source test_ex_undo.vim
+source test_expr.vim
+source test_expr_utf8.vim
 source test_feedkeys.vim
 source test_cmdline.vim
 source test_menu.vim
diff --git a/src/nvim/testdir/test_expr.vim b/src/nvim/testdir/test_expr.vim
new file mode 100644
index 0000000000..7ea4ebc7df
--- /dev/null
+++ b/src/nvim/testdir/test_expr.vim
@@ -0,0 +1,25 @@
+" Tests for expressions.
+
+func Test_strgetchar()
+  call assert_equal(char2nr('a'), strgetchar('axb', 0))
+  call assert_equal(char2nr('x'), strgetchar('axb', 1))
+  call assert_equal(char2nr('b'), strgetchar('axb', 2))
+
+  call assert_equal(-1, strgetchar('axb', -1))
+  call assert_equal(-1, strgetchar('axb', 3))
+  call assert_equal(-1, strgetchar('', 0))
+endfunc
+
+func Test_strcharpart()
+  call assert_equal('a', strcharpart('axb', 0, 1))
+  call assert_equal('x', strcharpart('axb', 1, 1))
+  call assert_equal('b', strcharpart('axb', 2, 1))
+  call assert_equal('xb', strcharpart('axb', 1))
+
+  call assert_equal('', strcharpart('axb', 1, 0))
+  call assert_equal('', strcharpart('axb', 1, -1))
+  call assert_equal('', strcharpart('axb', -1, 1))
+  call assert_equal('', strcharpart('axb', -2, 2))
+
+  call assert_equal('a', strcharpart('axb', -1, 2))
+endfunc
diff --git a/src/nvim/testdir/test_expr_utf8.vim b/src/nvim/testdir/test_expr_utf8.vim
new file mode 100644
index 0000000000..7bdcb4f65f
--- /dev/null
+++ b/src/nvim/testdir/test_expr_utf8.vim
@@ -0,0 +1,38 @@
+" Tests for expressions using utf-8.
+if !has('multi_byte')
+  finish
+endif
+scriptencoding utf-8
+
+func Test_strgetchar_utf8()
+  call assert_equal(char2nr('á'), strgetchar('áxb', 0))
+  call assert_equal(char2nr('x'), strgetchar('áxb', 1))
+
+  call assert_equal(char2nr('a'), strgetchar('àxb', 0))
+  call assert_equal(char2nr('̀'), strgetchar('àxb', 1))
+  call assert_equal(char2nr('x'), strgetchar('àxb', 2))
+
+  call assert_equal(char2nr('あ'), strgetchar('あaい', 0))
+  call assert_equal(char2nr('a'), strgetchar('あaい', 1))
+  call assert_equal(char2nr('い'), strgetchar('あaい', 2))
+endfunc
+
+func Test_strcharpart_utf8()
+  call assert_equal('áxb', strcharpart('áxb', 0))
+  call assert_equal('á', strcharpart('áxb', 0, 1))
+  call assert_equal('x', strcharpart('áxb', 1, 1))
+
+  call assert_equal('いうeお', strcharpart('あいうeお', 1))
+  call assert_equal('い', strcharpart('あいうeお', 1, 1))
+  call assert_equal('いう', strcharpart('あいうeお', 1, 2))
+  call assert_equal('いうe', strcharpart('あいうeお', 1, 3))
+  call assert_equal('いうeお', strcharpart('あいうeお', 1, 4))
+  call assert_equal('eお', strcharpart('あいうeお', 3))
+  call assert_equal('e', strcharpart('あいうeお', 3, 1))
+
+  call assert_equal('あ', strcharpart('あいうeお', -3, 4))
+
+  call assert_equal('a', strcharpart('àxb', 0, 1))
+  call assert_equal('̀', strcharpart('àxb', 1, 1))
+  call assert_equal('x', strcharpart('àxb', 2, 1))
+endfunc