fix(api, lua): handle setting v: variables properly (#25325)

2 files changed, 105 insertions, 9 deletions

diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index fcf3eae5ec..d82e5f66c9 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -1350,15 +1350,59 @@ describe('API', function()
     end)
 
     it('nvim_get_vvar, nvim_set_vvar', function()
-      -- Set readonly v: var.
-      eq('Key is read-only: count',
-        pcall_err(request, 'nvim_set_vvar', 'count', 42))
-      -- Set non-existent v: var.
-      eq('Dictionary is locked',
-        pcall_err(request, 'nvim_set_vvar', 'nosuchvar', 42))
-      -- Set writable v: var.
+      eq('Key is read-only: count', pcall_err(request, 'nvim_set_vvar', 'count', 42))
+      eq('Dictionary is locked', pcall_err(request, 'nvim_set_vvar', 'nosuchvar', 42))
       meths.set_vvar('errmsg', 'set by API')
       eq('set by API', meths.get_vvar('errmsg'))
+      meths.set_vvar('errmsg', 42)
+      eq('42', eval('v:errmsg'))
+      meths.set_vvar('oldfiles', { 'one', 'two' })
+      eq({ 'one', 'two' }, eval('v:oldfiles'))
+      meths.set_vvar('oldfiles', {})
+      eq({}, eval('v:oldfiles'))
+      eq('Setting v:oldfiles to value with wrong type', pcall_err(meths.set_vvar, 'oldfiles', 'a'))
+      eq({}, eval('v:oldfiles'))
+
+      feed('i foo foo foo<Esc>0/foo<CR>')
+      eq({1, 1}, meths.win_get_cursor(0))
+      eq(1, eval('v:searchforward'))
+      feed('n')
+      eq({1, 5}, meths.win_get_cursor(0))
+      meths.set_vvar('searchforward', 0)
+      eq(0, eval('v:searchforward'))
+      feed('n')
+      eq({1, 1}, meths.win_get_cursor(0))
+      meths.set_vvar('searchforward', 1)
+      eq(1, eval('v:searchforward'))
+      feed('n')
+      eq({1, 5}, meths.win_get_cursor(0))
+
+      local screen = Screen.new(60, 3)
+      screen:set_default_attr_ids({
+        [0] = {bold = true, foreground = Screen.colors.Blue},
+        [1] = {background = Screen.colors.Yellow},
+      })
+      screen:attach()
+      eq(1, eval('v:hlsearch'))
+      screen:expect{grid=[[
+         {1:foo} {1:^foo} {1:foo}                                                |
+        {0:~                                                           }|
+                                                                    |
+      ]]}
+      meths.set_vvar('hlsearch', 0)
+      eq(0, eval('v:hlsearch'))
+      screen:expect{grid=[[
+         foo ^foo foo                                                |
+        {0:~                                                           }|
+                                                                    |
+      ]]}
+      meths.set_vvar('hlsearch', 1)
+      eq(1, eval('v:hlsearch'))
+      screen:expect{grid=[[
+         {1:foo} {1:^foo} {1:foo}                                                |
+        {0:~                                                           }|
+                                                                    |
+      ]]}
     end)
 
     it('vim_set_var returns the old value', function()
diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index cf80478b08..bd3d8f5247 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -1491,8 +1491,60 @@ describe('lua stdlib', function()
     eq(NIL, funcs.luaeval "vim.v.null")
     matches([[attempt to index .* nil value]],
        pcall_err(exec_lua, 'return vim.v[0].progpath'))
-    eq('Key is read-only: count', pcall_err(exec_lua, 'vim.v.count = 42'))
-    eq('Dictionary is locked', pcall_err(exec_lua, 'vim.v.nosuchvar = 42'))
+    eq('Key is read-only: count', pcall_err(exec_lua, [[vim.v.count = 42]]))
+    eq('Dictionary is locked', pcall_err(exec_lua, [[vim.v.nosuchvar = 42]]))
+    eq('Key is fixed: errmsg', pcall_err(exec_lua, [[vim.v.errmsg = nil]]))
+    exec_lua([[vim.v.errmsg = 'set by Lua']])
+    eq('set by Lua', eval('v:errmsg'))
+    exec_lua([[vim.v.errmsg = 42]])
+    eq('42', eval('v:errmsg'))
+    exec_lua([[vim.v.oldfiles = { 'one', 'two' }]])
+    eq({ 'one', 'two' }, eval('v:oldfiles'))
+    exec_lua([[vim.v.oldfiles = {}]])
+    eq({}, eval('v:oldfiles'))
+    eq('Setting v:oldfiles to value with wrong type', pcall_err(exec_lua, [[vim.v.oldfiles = 'a']]))
+    eq({}, eval('v:oldfiles'))
+
+    feed('i foo foo foo<Esc>0/foo<CR>')
+    eq({1, 1}, meths.win_get_cursor(0))
+    eq(1, eval('v:searchforward'))
+    feed('n')
+    eq({1, 5}, meths.win_get_cursor(0))
+    exec_lua([[vim.v.searchforward = 0]])
+    eq(0, eval('v:searchforward'))
+    feed('n')
+    eq({1, 1}, meths.win_get_cursor(0))
+    exec_lua([[vim.v.searchforward = 1]])
+    eq(1, eval('v:searchforward'))
+    feed('n')
+    eq({1, 5}, meths.win_get_cursor(0))
+
+    local screen = Screen.new(60, 3)
+    screen:set_default_attr_ids({
+      [0] = {bold = true, foreground = Screen.colors.Blue},
+      [1] = {background = Screen.colors.Yellow},
+    })
+    screen:attach()
+    eq(1, eval('v:hlsearch'))
+    screen:expect{grid=[[
+       {1:foo} {1:^foo} {1:foo}                                                |
+      {0:~                                                           }|
+                                                                  |
+    ]]}
+    exec_lua([[vim.v.hlsearch = 0]])
+    eq(0, eval('v:hlsearch'))
+    screen:expect{grid=[[
+       foo ^foo foo                                                |
+      {0:~                                                           }|
+                                                                  |
+    ]]}
+    exec_lua([[vim.v.hlsearch = 1]])
+    eq(1, eval('v:hlsearch'))
+    screen:expect{grid=[[
+       {1:foo} {1:^foo} {1:foo}                                                |
+      {0:~                                                           }|
+                                                                  |
+    ]]}
   end)
 
   it('vim.bo', function()