feat: show diff between actual and expected output

[shadmansaleh]

closes #10

[xeluxee]

I've noticed that when I close and reopen CompetiTest window diff view isn't restored if previously enabled. The following patch fixes it, removes changes to resize_ui function (since diffview is enabled in show_ui) and simplifies toggle_diff_view logic.

diff --git a/lua/competitest/runner_ui/init.lua b/lua/competitest/runner_ui/init.lua
index 73be596..d19915e 100644
--- a/lua/competitest/runner_ui/init.lua
+++ b/lua/competitest/runner_ui/init.lua
@@ -51,13 +51,11 @@ end
 function RunnerUI:resize_ui()
    local cursor_position = self.ui_visible and api.nvim_win_get_cursor(self.windows.tc.winid) -- restore cursor position later
    local was_viewer_visible = self.viewer_visible -- make viewer visible later
-   local was_diff_enabled = self.diff_view_enabled -- store diff state
    self:delete()
    if cursor_position then -- if cursor_position isn't nil ui was visible
        self:show_ui()
        vim.schedule(function()
            self.make_viewer_visible = was_viewer_visible -- make update_ui() open viewer after updating details
-           self.enable_diff = was_diff_enabled -- make update_ui() enable diff
            api.nvim_win_set_cursor(self.windows.tc.winid, cursor_position)
        end)
    end
@@ -197,32 +195,40 @@ function RunnerUI:show_ui()
        self.interface.show_ui(self.windows)
        self.ui_visible = true
    end
+
+   if self.diff_view_enabled then -- enable diff view if previously enabled
+       self.diff_view_enabled = false
+       self:toggle_diff_view()
+   end
    api.nvim_set_current_win(self.windows.tc.winid)
 end

--- Enable Diff view
+---Enable or disable diffview in given window
+---@param winid integer
+---@param enable_diff boolean
+local function win_set_diff(winid, enable_diff)
+   api.nvim_win_call(winid, function()
+       api.nvim_command(enable_diff and "diffthis" or "diffoff")
+   end)
+end
+
+---Toggle diffview between standard output and expected output windows
 function RunnerUI:toggle_diff_view()
-   if not self.diff_view_enabled then
-       vim.api.nvim_win_call(self.windows.eo.winid, function ()
-           vim.cmd('diffthis')
-       end)
-       vim.api.nvim_win_call(self.windows.so.winid, function ()
-           vim.cmd('diffthis')
-       end)
-   else
-       vim.api.nvim_win_call(self.windows.eo.winid, function ()
-           vim.cmd('diffoff')
-       end)
-       vim.api.nvim_win_call(self.windows.so.winid, function ()
-           vim.cmd('diffoff')
-       end)
-   end
    self.diff_view_enabled = not self.diff_view_enabled
+   win_set_diff(self.windows.eo.winid, self.diff_view_enabled)
+   win_set_diff(self.windows.so.winid, self.diff_view_enabled)
+end
+
+---Disable diffview between standard output and expected output windows
+function RunnerUI:disable_diff_view()
+   win_set_diff(self.windows.eo.winid, false)
+   win_set_diff(self.windows.so.winid, false)
 end

 ---Hide RunnerUI preserving buffers, so it can be shown later
 function RunnerUI:hide_ui()
    if self.ui_visible then
+       self:disable_diff_view() -- disable diff when closing windows to prevent conflicts with other diffviews
        for _, w in pairs(self.windows) do
            if w then -- if a window is uninitialized its value is nil
                w:hide()
@@ -230,13 +236,15 @@ function RunnerUI:hide_ui()
        end
        self.ui_visible = false
        self.viewer_visible = false
-       self.diff_view_enabled = false
        api.nvim_set_current_win(self.restore_winid or 0)
    end
 end

 ---Delete RunnerUI and uninitialize all the windows
 function RunnerUI:delete()
+   if self.ui_visible then
+       self:disable_diff_view() -- disable diff when closing windows to prevent conflicts with other diffviews
+   end
    for _, w in pairs(self.windows) do
        if w then -- if a window is uninitialized its value is nil
            w:unmount()
@@ -247,7 +255,6 @@ function RunnerUI:delete()
    self.ui_visible = false
    self.viewer_initialized = false
    self.viewer_visible = false
-   self.diff_view_enabled = false
    api.nvim_set_current_win(self.restore_winid or 0)
 end

@@ -398,10 +405,6 @@ function RunnerUI:update_ui()
            self.make_viewer_visible = nil
            self:show_viewer_popup()
        end
-       if self.enable_diff then
-           self.enable_diff = nil
-           self:toggle_diff_view()
-       end
    end)
 end

[shadmansaleh]

I've noticed that when I close and reopen CompetiTest window diff view isn't restored if previously enabled.

That was actually intentional I though competitest winodws should open in default view.

We can do it your way.

By the way did you edit the patch it doesn't seem to directly apply. I guess I'll have to manually apply it.

[xeluxee]

When output and expected output are exactly the same, text gets folded, so they're hidden. @shadmansaleh do you think we should set foldlevel=999 to prevent this?

[xeluxee]

I've just pushed a commit with the following changes:

1. Set foldlevel to 1 for stdout and expected output windows
2. Added view_output_diff setup option to let users enable diff view by default
3. Updated README.md

@shadmansaleh let me know if there's still something to add or fix before merging