1 files changed, 48 insertions, 0 deletions
diff --git a/src/nvim/testdir/test_expr.vim b/src/nvim/testdir/test_expr.vim
new file mode 100644
index 0000000000..5c70dcb25e
--- /dev/null
+++ b/src/nvim/testdir/test_expr.vim
@@ -0,0 +1,48 @@
+" 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))
+
+  if !has('multi_byte')
+    return
+  endif
+
+  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))
+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))
+
+  if !has('multi_byte')
+    return
+  endif
+
+  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('a', strcharpart('àxb', 0, 1))
+  call assert_equal('', strcharpart('àxb', 1, 1))
+  call assert_equal('x', strcharpart('àxb', 2, 1))
+endfunc