feat: inlay hints

.luarc.json

@@ -3,5 +3,6 @@
         "describe",
         "it",
         "before_each",
+        "after_each",
     ]
 }

lua/precognition/compat.lua

@@ -0,0 +1,10 @@
+local M = {}
+
+function M.inlay_hints_enabled(t)
+    if vim.lsp and vim.lsp.inlay_hint and vim.lsp.inlay_hint.is_enabled then
+        return vim.lsp.inlay_hint.is_enabled(t)
+    end
+    return false
+end
+
+return M

lua/precognition/init.lua

@@ -1,6 +1,7 @@
 local hm = require("precognition.horizontal_motions")
 local vm = require("precognition.vertical_motions")
 local utils = require("precognition.utils")
+local compat = require("precognition.compat")
 
 local M = {}
 
@@ -54,6 +55,10 @@ local M = {}
 ---@field PrevParagraph Precognition.PlaceLoc
 ---@field NextParagraph Precognition.PlaceLoc
 
+---@class Precognition.ExtraPadding
+---@field start integer
+---@field length integer
+
 ---@type Precognition.HintConfig
 local defaultHintConfig = {
     Caret = { text = "^", prio = 2 },
@@ -106,8 +111,9 @@ local gutter_group = "precognition_gutter"
 
 ---@param marks Precognition.VirtLine
 ---@param line_len integer
+---@param extra_padding Precognition.ExtraPadding[]
 ---@return table
-local function build_virt_line(marks, line_len)
+local function build_virt_line(marks, line_len, extra_padding)
     if not marks then
         return {}
     end
@@ -141,6 +147,12 @@ local function build_virt_line(marks, line_len)
         end
     end
 
+    if #extra_padding > 0 then
+        for _, padding in ipairs(extra_padding) do
+            line_table[padding.start] = line_table[padding.start] .. string.rep(" ", padding.length)
+        end
+    end
+
     local line = table.concat(line_table)
     if line:match("^%s+$") then
         return {}
@@ -210,6 +222,8 @@ local function display_marks()
     local tab_width = vim.bo.expandtab and vim.bo.shiftwidth or vim.bo.tabstop
     local cur_line = vim.api.nvim_get_current_line():gsub("\t", string.rep(" ", tab_width))
     local line_len = vim.fn.strcharlen(cur_line)
+    ---@type Precognition.ExtraPadding[]
+    local extra_padding = {}
     -- local after_cursor = vim.fn.strcharpart(cur_line, cursorcol + 1)
     -- local before_cursor = vim.fn.strcharpart(cur_line, 0, cursorcol - 1)
     -- local before_cursor_rev = string.reverse(before_cursor)
@@ -232,7 +246,22 @@ local function display_marks()
         Zero = 1,
     }
 
-    local virt_line = build_virt_line(virtual_line_marks, line_len)
+    if compat.inlay_hints_enabled({ bufnr = 0 }) then
+        local inlays_hints = vim.lsp.inlay_hint.get({
+            bufnr = 0,
+            range = {
+                start = { line = cursorline - 1, character = 0 },
+                ["end"] = { line = cursorline - 1, character = line_len - 1 },
+            },
+        })
+
+        for _, hint in ipairs(inlays_hints) do
+            local length, ws_offset = utils.calc_ws_offset(hint, tab_width, vim.api.nvim_get_current_line())
+            table.insert(extra_padding, { start = ws_offset, length = length })
+        end
+    end
+
+    local virt_line = build_virt_line(virtual_line_marks, line_len, extra_padding)
 
     -- TODO: can we add indent lines to the virt line to match indent-blankline or similar (if installed)?
 

lua/precognition/utils.lua

@@ -49,4 +49,21 @@ function M.create_pad_array(len, str)
     return pad_array
 end
 
+---calculates the white space offset of a partial string
+---@param hint vim.lsp.inlay_hint.get.ret
+---@param tab_width integer
+---@param current_line string
+---@return integer
+---@return integer
+function M.calc_ws_offset(hint, tab_width, current_line)
+    -- + 1 here because of trailing padding
+    local length = #hint.inlay_hint.label[1].value + 1
+    local start = hint.inlay_hint.position.character
+    local prefix = vim.fn.strcharpart(current_line, 0, start)
+    local expanded = string.gsub(prefix, "\t", string.rep(" ", tab_width))
+    vim.print(expanded)
+    local ws_offset = vim.fn.strcharlen(expanded)
+    return length, ws_offset
+end
+
 return M

tests/precognition/e2e_spec.lua

@@ -1,32 +1,8 @@
 local precognition = require("precognition")
+local tu = require("tests.precognition.utils.utils")
 ---@diagnostic disable-next-line: undefined-field
 local eq = assert.are.same
 
-local function get_gutter_extmarks(buffer)
-    local gutter_extmarks = {}
-    for _, extmark in
-        pairs(vim.api.nvim_buf_get_extmarks(buffer, -1, 0, -1, {
-            details = true,
-        }))
-    do
-        if extmark[4] and extmark[4].sign_name and extmark[4].sign_name:match(precognition.gutter_group) then
-            table.insert(gutter_extmarks, extmark)
-        end
-    end
-    return gutter_extmarks
-end
-
-local function hex2dec(hex)
-    hex = hex:gsub("#", "")
-    local r = tonumber("0x" .. hex:sub(1, 2))
-    local g = tonumber("0x" .. hex:sub(3, 4))
-    local b = tonumber("0x" .. hex:sub(5, 6))
-
-    local dec = (r * 256 ^ 2) + (g * 256) + b
-
-    return dec
-end
-
 describe("e2e tests", function()
     before_each(function()
         precognition.setup({})
@@ -65,7 +41,7 @@ describe("e2e tests", function()
             details = true,
         })
 
-        local gutter_extmarks = get_gutter_extmarks(buffer)
+        local gutter_extmarks = tu.get_gutter_extmarks(buffer)
 
         for _, extmark in pairs(gutter_extmarks) do
             if extmark[4].sign_text == "G " then
@@ -104,7 +80,7 @@ describe("e2e tests", function()
         vim.api.nvim_win_set_cursor(0, { 2, 1 })
         precognition.on_cursor_moved()
 
-        gutter_extmarks = get_gutter_extmarks(buffer)
+        gutter_extmarks = tu.get_gutter_extmarks(buffer)
 
         extmarks = vim.api.nvim_buf_get_extmark_by_id(buffer, precognition.ns, precognition.extmark, {
             details = true,
@@ -129,7 +105,7 @@ describe("e2e tests", function()
 
         vim.api.nvim_win_set_cursor(0, { 4, 1 })
         precognition.on_cursor_moved()
-        gutter_extmarks = get_gutter_extmarks(buffer)
+        gutter_extmarks = tu.get_gutter_extmarks(buffer)
 
         for _, extmark in pairs(gutter_extmarks) do
             if extmark[4].sign_text == "G " then
@@ -165,7 +141,7 @@ describe("e2e tests", function()
             details = true,
         })
 
-        local gutter_extmarks = get_gutter_extmarks(buffer)
+        local gutter_extmarks = tu.get_gutter_extmarks(buffer)
 
         for _, extmark in pairs(gutter_extmarks) do
             if extmark[4].sign_text == "G " then
@@ -199,7 +175,7 @@ describe("e2e tests", function()
         local background = "#00ff00"
         local foreground = "#ff0000"
         local customColor = { foreground = foreground, background = background }
-        local customMark = { fg = hex2dec(foreground), bg = hex2dec(background) }
+        local customMark = { fg = tu.hex2dec(foreground), bg = tu.hex2dec(background) }
         precognition.setup({ highlightColor = customColor })
         local buffer = vim.api.nvim_create_buf(true, false)
         vim.api.nvim_set_current_buf(buffer)
@@ -218,7 +194,7 @@ describe("e2e tests", function()
             details = true,
         })
 
-        local gutter_extmarks = get_gutter_extmarks(buffer)
+        local gutter_extmarks = tu.get_gutter_extmarks(buffer)
 
         for _, extmark in pairs(gutter_extmarks) do
             if extmark[4].sign_text == "G " then

tests/precognition/inlay_hints_spec.lua

@@ -0,0 +1,74 @@
+local server = require("tests.precognition.utils.lsp").server
+local compat = require("tests.precognition.utils.compat")
+local precognition = require("precognition")
+---@diagnostic disable-next-line: undefined-field
+local eq = assert.are.same
+---@diagnostic disable-next-line: undefined-field
+local neq = assert.are_not.same
+local buf
+
+local function wait(condition, msg)
+    vim.wait(100, condition)
+    local result = condition()
+    neq(false, result, msg)
+    neq(nil, result, msg)
+end
+
+describe("lsp based tests", function()
+    before_each(function()
+        require("tests.precognition.utils.lsp").Reset()
+        buf = vim.api.nvim_create_buf(true, false)
+        local srv = vim.lsp.start_client({ cmd = server })
+        if srv then
+            vim.lsp.buf_attach_client(buf, srv)
+        end
+    end)
+
+    it("initialize lsp", function()
+        eq(2, #require("tests.precognition.utils.lsp").messages)
+        eq("initialize", require("tests.precognition.utils.lsp").messages[1].method)
+        eq("initialized", require("tests.precognition.utils.lsp").messages[2].method)
+    end)
+
+    it("can enable inlay hints", function()
+        vim.lsp.inlay_hint.enable(true, { bufnr = buf })
+
+        eq(3, #require("tests.precognition.utils.lsp").messages)
+        eq("textDocument/inlayHint", require("tests.precognition.utils.lsp").messages[3].method)
+    end)
+
+    it("inlay hint shifts the line", function()
+        vim.api.nvim_buf_set_lines(buf, 0, -1, false, { "here is a string" })
+        vim.api.nvim_set_current_buf(buf)
+        vim.api.nvim_win_set_cursor(0, { 1, 1 })
+
+        precognition.on_cursor_moved()
+
+        local extmarks = vim.api.nvim_buf_get_extmark_by_id(buf, precognition.ns, precognition.extmark, {
+            details = true,
+        })
+
+        eq("b  e w         $", extmarks[3].virt_lines[1][1][1])
+
+        vim.lsp.inlay_hint.enable(true, { bufnr = buf })
+        -- NOTE:The test LSP replies with an inlay hint, that suggest "foo" as line 1, position 4
+        --          This means that the inlay hint is shifted by 3 chars
+
+        precognition.on_cursor_moved()
+
+        extmarks = vim.api.nvim_buf_get_extmark_by_id(buf, precognition.ns, precognition.extmark, {
+            details = true,
+        })
+
+        eq("b      e w         $", extmarks[3].virt_lines[1][1][1])
+    end)
+
+    after_each(function()
+        vim.lsp.inlay_hint.enable(false, { bufnr = buf })
+        vim.api.nvim_buf_delete(buf, { force = true })
+        vim.lsp.stop_client(compat.get_active_lsp_clients())
+        wait(function()
+            return vim.tbl_count(compat.get_active_lsp_clients()) == 0
+        end, "clients must stop")
+    end)
+end)

tests/precognition/utils/compat.lua

@@ -0,0 +1,5 @@
+local M = {}
+
+M.get_active_lsp_clients = vim.lsp.get_clients() or vim.lsp.get_active_clients()
+
+return M

tests/precognition/utils/lsp.lua

@@ -0,0 +1,53 @@
+local M = {}
+
+M.messages = {}
+
+function M.server()
+    local closing = false
+    local srv = {}
+
+    function srv.request(method, params, handler)
+        table.insert(M.messages, { method = method, params = params })
+        if method == "initialize" then
+            handler(nil, {
+                capabilities = {
+                    inlayHintProvider = true,
+                },
+            })
+        elseif method == "shutdown" then
+            handler(nil, nil)
+        elseif method == "textDocument/inlayHint" then
+            handler(nil, {
+                {
+                    position = { line = 0, character = 3 },
+                    label = { { value = "foo" } },
+                },
+            })
+        else
+            assert(false, "Unhandled method: " .. method)
+        end
+    end
+
+    function srv.notify(method, params)
+        table.insert(M.messages, { method = method, params = params })
+        if method == "exit" then
+            closing = true
+        end
+    end
+
+    function srv.is_closing()
+        return closing
+    end
+
+    function srv.terminate()
+        closing = true
+    end
+
+    return srv
+end
+
+function M.Reset()
+    M.messages = {}
+end
+
+return M

tests/precognition/utils/utils.lua

@@ -0,0 +1,30 @@
+local precognition = require("precognition")
+
+local M = {}
+
+function M.get_gutter_extmarks(buffer)
+    local gutter_extmarks = {}
+    for _, extmark in
+        pairs(vim.api.nvim_buf_get_extmarks(buffer, -1, 0, -1, {
+            details = true,
+        }))
+    do
+        if extmark[4] and extmark[4].sign_name and extmark[4].sign_name:match(precognition.gutter_group) then
+            table.insert(gutter_extmarks, extmark)
+        end
+    end
+    return gutter_extmarks
+end
+
+function M.hex2dec(hex)
+    hex = hex:gsub("#", "")
+    local r = tonumber("0x" .. hex:sub(1, 2))
+    local g = tonumber("0x" .. hex:sub(3, 4))
+    local b = tonumber("0x" .. hex:sub(5, 6))
+
+    local dec = (r * 256 ^ 2) + (g * 256) + b
+
+    return dec
+end
+
+return M