feat: Customizable display_counter - closes #104

Author: andrewferrier

README.md

@@ -200,13 +200,31 @@ reason, please open an
 
 `debugprint` supports the following options in its global `opts` object:
 
-| Option              | Default      | Purpose                                                                                                                                      |
-| ------------------- | ------------ | -------------------------------------------------------------------------------------------------------------------------------------------- |
-| `move_to_debugline` | `false`      | When adding a debug line, moves the cursor to that line                                                                                      |
-| `display_counter`   | `true`       | Whether to display/include the monotonically increasing counter in each debug message                                                        |
-| `display_snippet`   | `true`       | Whether to include a snippet of the line above/below in plain debug lines                                                                    |
-| `filetypes`         | See below    | Custom filetypes - see below                                                                                                                 |
-| `print_tag`         | `DEBUGPRINT` | The string inserted into each print statement, which can be used to uniquely identify statements inserted by `debugprint`.                   |
+| Option              | Default      | Purpose                                                                                                                                |
+| ------------------- | ------------ | -------------------------------------------------------------------------------------------------------------------------------------- |
+| `move_to_debugline` | `false`      | When adding a debug line, moves the cursor to that line                                                                                |
+| `display_counter`   | `true`       | Whether to display/include the increasing integer counter in each debug message. Can also be set to a function to customize, see below |
+| `display_snippet`   | `true`       | Whether to include a snippet of the line above/below in plain debug lines                                                              |
+| `filetypes`         | See below    | Custom filetypes - see below                                                                                                           |
+| `print_tag`         | `DEBUGPRINT` | The string inserted into each print statement, which can be used to uniquely identify statements inserted by `debugprint`.             |
+
+### Customizing Counter Logic
+
+`display_counter` can also be set to a custom callback function to implement
+custom counter logic. In this case you are responsible for implementing your own
+counter. For example, this logic will implement essentially the same as the
+default counter:
+
+```lua
+local counter = 0
+
+local counter_func = function()
+    counter = counter + 1
+    return '[' .. tostring(counter) .. ']'
+end
+
+debugprint.setup({display_counter = counter_func})
+```
 
 ## Add Custom Filetypes
 

lua/debugprint/init.lua

@@ -3,7 +3,7 @@ local M = {}
 local utils = require("debugprint.utils")
 
 local global_opts
-local counter = 0
+local default_counter = 0
 
 MAX_SNIPPET_LENGTH = 40
 
@@ -44,15 +44,20 @@ local get_snippet = function(current_line, above)
     return line_contents
 end
 
+local default_display_counter = function()
+    default_counter = default_counter + 1
+    return "[" .. tostring(default_counter) .. "]"
+end
+
 local debuginfo = function(opts)
     local current_line = vim.api.nvim_win_get_cursor(0)[1]
 
-    counter = counter + 1
-
     local line = global_opts.print_tag
 
-    if global_opts.display_counter then
-        line = line .. "[" .. counter .. "]"
+    if global_opts.display_counter == true then
+        line = line .. default_display_counter()
+    elseif type(global_opts.display_counter) == "function" then
+        line = line .. tostring(global_opts.display_counter())
     end
 
     line = line .. ": " .. vim.fn.expand("%:t") .. ":" .. current_line
@@ -307,7 +312,7 @@ M.setup = function(opts)
     require("debugprint.setup").map_keys_and_commands(global_opts)
 
     -- Because we want to be idempotent, re-running setup() resets the counter
-    counter = 0
+    default_counter = 0
 end
 
 M.add_custom_filetypes = function(filetypes)

lua/debugprint/options.lua

@@ -37,7 +37,7 @@ local validate_global_opts = function(o)
     vim.validate({
         keymaps = { o.keymaps, "table" },
         commands = { o.commands, "table" },
-        display_counter = { o.display_counter, "boolean" },
+        display_counter = { o.display_counter, { "function", "boolean" }},
         display_snippet = { o.display_snippet, "boolean" },
         move_to_debugline = { o.move_to_debugline, "boolean" },
         ignore_treesitter = { o.ignore_treesitter, "boolean" },

tests/debugprint.lua

@@ -85,6 +85,7 @@ local teardown = function()
     pcall(vim.keymap.del, { "n", "x" }, "g?V")
     pcall(vim.keymap.del, "n", "g?o")
     pcall(vim.keymap.del, "n", "g?O")
+    vim.cmd("set modifiable")
 end
 
 describe("can do setup()", function()
@@ -2013,3 +2014,43 @@ describe("unmodifiable buffer", function()
         assert.equals(notify_message, "Buffer is not modifiable.")
     end)
 end)
+
+describe("custom counter", function()
+    local count = 0
+
+    before_each(function()
+        debugprint.setup({
+            display_counter = function(opts)
+                count = count + 2
+                return "-" .. tostring(count) .. "x"
+            end,
+        })
+    end)
+
+    after_each(teardown)
+
+    it("basic", function()
+        local filename = init_file({
+            "foo",
+            "bar",
+        }, "lua", 1, 0)
+
+        feedkeys("g?p")
+        feedkeys("g?p")
+        feedkeys("g?p")
+
+        check_lines({
+            "foo",
+            "print('DEBUGPRINT-6x: "
+                .. filename
+                .. ":1 (after foo)')",
+            "print('DEBUGPRINT-4x: "
+                .. filename
+                .. ":1 (after foo)')",
+            "print('DEBUGPRINT-2x: "
+                .. filename
+                .. ":1 (after foo)')",
+            "bar",
+        })
+    end)
+end)