feat: support "prio" priority value for gutter marks (#43)

Co-authored-by: tris203 <[email protected]>

README.md

@@ -35,29 +35,33 @@ return {
     --      E = { text = "E", prio = 5 },
     -- },
     -- gutterHints = {
-    --     -- prio is not currently used for gutter hints
-    --     G = { text = "G", prio = 1 },
-    --     gg = { text = "gg", prio = 1 },
-    --     PrevParagraph = { text = "{", prio = 1 },
-    --     NextParagraph = { text = "}", prio = 1 },
+    --     G = { text = "G", prio = 10 },
+    --     gg = { text = "gg", prio = 9 },
+    --     PrevParagraph = { text = "{", prio = 8 },
+    --     NextParagraph = { text = "}", prio = 8 },
     -- },
     },
 }
 ```
 
 ## ⚙️ Config
 
-- Items can be hidden by settings their priority to 0, if you want to hide the
-  entire virtual line. Set all elements to `prio = 0` in combination with the
+- `hints` can be hidden by setting their priority to 0. If you want to hide the
+  entire virtual line, set all elements to `prio = 0` in combination with the
   below.
 - `showBlankVirtLine = false`
-  Setting this option will mean that if a Virtual Line would be blank it wont be
+  Setting this option will mean that if a Virtual Line would be blank it won't be
   rendered
-- highlightColor can be set in two ways:
+- `gutterHints` can be hidden by setting their priority to 0.
+- `highlightColor` can be set in two ways:
 
 1. As a table containing a link property pointing to an existing highlight group (see `:highlight` for valid options).
 2. As a table specifying custom highlight values, such as foreground and background colors. ([more info](<https://neovim.io/doc/user/api.html#nvim_set_hl()>))
 
+### Hint priorities
+
+Any hints that could appear in the same place as others should have unique priorities to avoid conflicts.
+
 ## ❔Usage
 
 ### Toggling

lua/precognition/init.lua

@@ -79,11 +79,10 @@ local default = {
     highlightColor = { link = "Comment" },
     hints = defaultHintConfig,
     gutterHints = {
-        --prio is not currentlt used for gutter hints
-        G = { text = "G", prio = 1 },
-        gg = { text = "gg", prio = 1 },
-        PrevParagraph = { text = "{", prio = 1 },
-        NextParagraph = { text = "}", prio = 1 },
+        G = { text = "G", prio = 10 },
+        gg = { text = "gg", prio = 9 },
+        PrevParagraph = { text = "{", prio = 8 },
+        NextParagraph = { text = "}", prio = 8 },
     },
 }
 
@@ -180,31 +179,47 @@ local function apply_gutter_hints(gutter_hints, bufnr)
     if utils.is_blacklisted_buffer(bufnr) then
         return
     end
+
+    local gutter_table = {}
     for hint, loc in pairs(gutter_hints) do
-        if config.gutterHints[hint] and loc ~= 0 and loc ~= nil then
-            if gutter_signs_cache[hint] then
-                vim.fn.sign_unplace(gutter_group, { id = gutter_signs_cache[hint].id })
-                gutter_signs_cache[hint] = nil
-            end
-            vim.fn.sign_define(gutter_name_prefix .. hint, {
-                text = config.gutterHints[hint].text,
-                texthl = "PrecognitionHighlight",
-            })
-            local ok, res = pcall(vim.fn.sign_place, 0, gutter_group, gutter_name_prefix .. hint, bufnr, {
-                lnum = loc,
-                priority = 100,
-            })
-            if ok then
-                gutter_signs_cache[hint] = { line = loc, id = res }
-            end
-            if not ok and loc ~= 0 then
-                vim.notify_once(
-                    "Failed to place sign: " .. hint .. " at line " .. loc .. vim.inspect(res),
-                    vim.log.levels.WARN
-                )
+        if gutter_signs_cache[hint] then
+            vim.fn.sign_unplace(gutter_group, { id = gutter_signs_cache[hint].id })
+            gutter_signs_cache[hint] = nil
+        end
+
+        local prio = config.gutterHints[hint].prio
+
+        -- Build table of valid and priorised gutter hints.
+        if loc ~= 0 and loc ~= nil and prio > 0 then
+            local existing = gutter_table[loc]
+            if not existing or existing.prio < prio then
+                gutter_table[loc] = { hint = hint, prio = prio }
             end
         end
     end
+
+    -- Only render valid and prioritised gutter hints.
+    for loc, data in pairs(gutter_table) do
+        local hint = data.hint
+        local sign_name = gutter_name_prefix .. hint
+        vim.fn.sign_define(sign_name, {
+            text = config.gutterHints[hint].text,
+            texthl = "PrecognitionHighlight",
+        })
+        local ok, res = pcall(vim.fn.sign_place, 0, gutter_group, sign_name, bufnr, {
+            lnum = loc,
+            priority = 100,
+        })
+        if ok then
+            gutter_signs_cache[hint] = { line = loc, id = res }
+        end
+        if not ok and loc ~= 0 then
+            vim.notify_once(
+                "Failed to place sign: " .. hint .. " at line " .. loc .. vim.inspect(res),
+                vim.log.levels.WARN
+            )
+        end
+    end
 end
 
 local function display_marks()

tests/precognition/e2e_spec.lua

@@ -248,3 +248,65 @@ describe("e2e tests", function()
         eq(customMark, vim.api.nvim_get_hl(0, { name = extmarks[3].virt_lines[1][1][2] }))
     end)
 end)
+
+describe("Gutter Priority", function()
+    it("0 priority item is not added", function()
+        precognition.setup({
+            ---@diagnostic disable-next-line: missing-fields
+            gutterHints = {
+                G = { text = "G", prio = 0 },
+            },
+        })
+
+        local testBuf = vim.api.nvim_create_buf(true, false)
+
+        vim.api.nvim_buf_set_lines(testBuf, 0, -1, false, {
+            "ABC",
+            "DEF",
+            "",
+            "GHI",
+            "",
+            "JKL",
+            "",
+            "MNO",
+        })
+        vim.api.nvim_set_current_buf(testBuf)
+        vim.api.nvim_win_set_cursor(0, { 4, 0 })
+
+        precognition.on_cursor_moved()
+
+        local gutter_extmarks = get_gutter_extmarks(testBuf)
+
+        for _, extmark in pairs(gutter_extmarks) do
+            eq(true, extmark[4].sign_text ~= "G ")
+            eq(true, extmark[4].sign_name ~= "precognition_gutter_G")
+        end
+    end)
+
+    it("higher priority item replaces", function()
+        precognition.setup({
+            ---@diagnostic disable-next-line: missing-fields
+            gutterHints = {
+                G = { text = "G", prio = 3 },
+                gg = { text = "gg", prio = 100 },
+                NextParagraph = { text = "}", prio = 2 },
+                PrevParagraph = { text = "{", prio = 1 },
+            },
+        })
+
+        local testBuf = vim.api.nvim_create_buf(true, false)
+
+        vim.api.nvim_buf_set_lines(testBuf, 0, -1, false, {
+            "ABC",
+        })
+        vim.api.nvim_set_current_buf(testBuf)
+        vim.api.nvim_win_set_cursor(0, { 1, 0 })
+
+        precognition.on_cursor_moved()
+
+        local gutter_extmarks = get_gutter_extmarks(testBuf)
+
+        eq(1, vim.tbl_count(gutter_extmarks))
+        eq("gg", gutter_extmarks[1][4].sign_text)
+    end)
+end)