1 files changed, 51 insertions, 1 deletions
diff --git a/test/functional/legacy/arglist_spec.lua b/test/functional/legacy/arglist_spec.lua
index a569479b62..e85d8a7aca 100644
--- a/test/functional/legacy/arglist_spec.lua
+++ b/test/functional/legacy/arglist_spec.lua
@@ -8,7 +8,19 @@ local eq, eval = helpers.eq, helpers.eval
 describe('argument list commands', function()
   before_each(clear)
 
-  it('is working', function()
+  function assert_argc(l)
+    eq(#l, eval('argc()'))
+    for i = 1, #l do
+      eq(l[i], eval('argv(' .. (i - 1) .. ')'))
+    end
+  end
+
+  function init_abc()
+    execute('args a b c')
+    execute('next')
+  end
+
+  it('test that argidx() works', function()
     execute('args a b c')
     execute('last')
     eq(2, eval('argidx()'))
@@ -28,4 +40,42 @@ describe('argument list commands', function()
     execute('1argdelete')
     eq(0, eval('argidx()'))
   end)
+
+  it('test that argadd() works', function()
+    execute('%argdelete')
+    execute('argadd a b c')
+    eq(0, eval('argidx()'))
+
+    execute('%argdelete')
+    execute('argadd a')
+    eq(0, eval('argidx()'))
+    execute('argadd b c d')
+    eq(0, eval('argidx()'))
+
+    init_abc()
+    execute('argadd x')
+    assert_argc({'a', 'b', 'x', 'c'})
+    eq(1, eval('argidx()'))
+
+    init_abc()
+    execute('0argadd x')
+    assert_argc({'x', 'a', 'b', 'c'})
+    eq(2, eval('argidx()'))
+
+    init_abc()
+    execute('1argadd x')
+    assert_argc({'a', 'x', 'b', 'c'})
+    eq(2, eval('argidx()'))
+
+    init_abc()
+    execute('$argadd x')
+    assert_argc({'a', 'b', 'c', 'x'})
+    eq(1, eval('argidx()'))
+
+    init_abc()
+    execute('$argadd x')
+    execute('+2argadd y')
+    assert_argc({'a', 'b', 'c', 'x', 'y'})
+    eq(1, eval('argidx()'))
+  end)
 end)