feat: goto definition

README.md

@@ -29,7 +29,8 @@ _Screenshot is showing the Snacks picker._
 
 ## Features
 
-- Browse and search Go standard library packages and project packages.
+- Search and browse docs for Go standard library packages and project packages.
+- Go to definition capability.
 - Syntax highlighting for Go documentation.
 - Optionally leverage [`stdsym`](https://github.com/lotusirous/gostdsym) for
   symbols searching.
@@ -89,6 +90,8 @@ provided:
 - `:GoDoc` - Open picker and search packages.
 - `:GoDoc <package>` - Directly open documentation for the specified package or
   symbol.
+- In Normal mode, press `gd` to go package definition (only supported by Snacks
+  and Telescope pickers). For fzf-lua, the keymap is `ctrl-s`.
 
 > [!WARNING]
 >
@@ -287,6 +290,7 @@ All adapters must implement the interface of `GoDocAdapter`:
 --- @field get_items fun(): string[] Function that returns a list of available items
 --- @field get_content fun(choice: string): string[] Function that returns the content
 --- @field get_syntax_info fun(): GoDocSyntaxInfo Function that returns syntax info
+--- @field goto_definition? fun(choice: string, picker_gotodef_fun: fun()?): nil Function that returns the definition location
 --- @field health? fun(): GoDocHealthCheck[] Optional health check function
 ```
 
@@ -299,6 +303,7 @@ The `opts` which can be passed into an adapter (by the user) is implemented by
 --- @field get_items? fun(): string[] Override the get_items function
 --- @field get_content? fun(choice: string): string[] Override the get_content function
 --- @field get_syntax_info? fun(): GoDocSyntaxInfo Override the get_syntax_info function
+--- @field goto_definition? fun(choice: string, picker_gotodef_fun: fun()?): nil Override the get_definition function
 --- @field health? fun(): GoDocHealthCheck[] Override the health check function
 --- @field [string] any Other adapter-specific options
 ```

lua/godoc/adapters/go.lua

@@ -84,6 +84,94 @@ local function get_packages()
 	return all_packages
 end
 
+--- @param item string
+--- @param picker_gotodef_fun fun()
+local function goto_definition(item, picker_gotodef_fun)
+	-- write temp file
+	local content = {}
+	local cursor_pos = {}
+	-- check if the chosen item contains a symbol
+	local is_symbol = string.match(item, "%.%a[%w_]*$") ~= nil
+	if is_symbol then
+		-- an import with symbol is passed, e.g. archive/tar.FileInfoNames
+		--
+		-- extract the import path (archive/tar)
+		local import_path = item:match("^(.-)%.")
+		-- extract the package name, which comes after the last slash (e.g. tar)
+		local package_name = import_path:match("([^/]+)$")
+		-- extract the symbol name, which comes after the last dot (e.g. FileInfoNames)
+		local symbol = item:match("([^%.]+)$")
+		-- the contents of the go file, which contains imports to the package and the symbol as well as the fmt package
+		local line = '  fmt.Printf("%v", ' .. package_name .. "." .. symbol .. ")"
+		content = {
+			"package main",
+			"",
+			"import (",
+			'  "' .. import_path .. '"',
+			'  "fmt"',
+			")",
+			"",
+			"func main() {",
+			line,
+			"}",
+		}
+		-- put the position/cursor on the symbol, e.g. on the 'F' of FileInfoNames
+		cursor_pos = { 9, line:find(symbol) + 1 }
+	else
+		-- a package name is passed, e.g. "archive/tar"
+		content = {
+			"package main",
+			"",
+			'import "' .. item .. '"',
+		}
+		cursor_pos = { 3, 9 }
+	end
+	local now = os.time()
+	local filename = "godoc_" .. now .. ".go"
+	local tempfile = vim.fn.getcwd() .. "/" .. filename
+	local go_mod_filepath = vim.fn.findfile("go.mod", vim.fn.getcwd() .. ";")
+	local go_mod_dir = vim.fn.fnamemodify(go_mod_filepath, ":p:h")
+	if go_mod_dir == "" then
+		vim.notify("Failed to find go.mod file, can only gotodef on std lib", vim.log.levels.WARN)
+	else
+		tempfile = go_mod_dir .. "/" .. filename
+	end
+	vim.fn.writefile(content, tempfile)
+
+	-- Open the temp file in the current (godoc-managed) buffer
+	vim.cmd("silent! e " .. tempfile)
+	local window = vim.api.nvim_get_current_win()
+	local buf = vim.api.nvim_get_current_buf()
+
+	-- Set buffer options
+	vim.api.nvim_set_option_value("filetype", "go", { buf = buf })
+	vim.api.nvim_set_option_value("bufhidden", "wipe", { buf = buf })
+	vim.diagnostic.enable(false, { bufnr = buf })
+
+	-- Wait until LSP has attached, can be queried and returns a client_id
+	local client_id = nil
+	local maxretries = 50
+	while client_id == nil and maxretries >= 0 do
+		for _, client in ipairs(vim.lsp.get_clients({ name = "gopls", bufnr = buf })) do
+			client_id = client.id
+			break
+		end
+		vim.wait(50)
+		maxretries = maxretries - 1
+	end
+
+	-- Position cursor at the right spot
+	vim.api.nvim_win_set_cursor(window, cursor_pos)
+
+	-- Execute goto definition in the new window
+	vim.api.nvim_win_call(window, function()
+		picker_gotodef_fun()
+	end)
+
+	-- Delete the temp file on disk
+	vim.fn.delete(tempfile)
+end
+
 local function health()
 	--- @type GoDocHealthCheck[]
 	local checks = {}
@@ -217,6 +305,9 @@ function M.setup(opts)
 				language = "go",
 			}
 		end,
+		goto_definition = function(choice, picker_gotodef_fun)
+			return goto_definition(choice, picker_gotodef_fun)
+		end,
 		health = health,
 	}
 end

lua/godoc/adapters/init.lua

@@ -44,6 +44,7 @@ function M.validate_adapter(adapter)
 		{ name = "get_items", type = "function" },
 		{ name = "get_content", type = "function" },
 		{ name = "get_syntax_info", type = "function" },
+		{ name = "goto_definition", type = "function" },
 	}
 
 	for _, field in ipairs(required_fields) do
@@ -70,6 +71,7 @@ function M.override_adapter(default_adapter, user_opts)
 		get_items = user_opts.get_items or default_adapter.get_items,
 		get_content = user_opts.get_content or default_adapter.get_content,
 		get_syntax_info = user_opts.get_syntax_info or default_adapter.get_syntax_info,
+		goto_definition = user_opts.goto_definition or default_adapter.goto_definition,
 		health = user_opts.health or default_adapter.health,
 	}
 end

lua/godoc/init.lua

@@ -82,6 +82,16 @@ local function configure_adapters(config)
 	return configured_adapters
 end
 
+--- Open window based on split type
+--- @param type 'split' | 'vsplit'
+local function open_window(type)
+	if type == "split" or type == "vsplit" then
+		vim.cmd(type)
+	else
+		vim.notify("Invalid window type: " .. type, vim.log.levels.ERROR)
+	end
+end
+
 -- Set up the plugin with user config
 --- @param opts? GoDocConfig
 function M.setup(opts)
@@ -104,9 +114,15 @@ function M.setup(opts)
 			local picker = pickers.get_picker(M.config.picker.type)
 			if picker then
 				---@type GoDocPicker
-				picker.show(adapter, M.config, function(choice)
-					if choice then
-						M.show_documentation(adapter, choice)
+				picker.show(adapter, M.config, function(data)
+					if data.choice then
+						if data.type == "show_documentation" then
+							open_window(M.config.window.type)
+							M.show_documentation(adapter, data.choice)
+						elseif data.type == "goto_definition" then
+							open_window(M.config.window.type)
+							M.goto_definition(adapter, data.choice, picker.goto_definition)
+						end
 					end
 				end)
 			else
@@ -130,15 +146,6 @@ function M.show_documentation(adapter, item)
 	vim.api.nvim_set_option_value("modifiable", false, { buf = buf })
 	vim.api.nvim_set_option_value("filetype", adapter.get_syntax_info().filetype, { buf = buf })
 
-	-- Open window based on config
-	if M.config.window.type == "split" then
-		vim.cmd("split")
-	elseif M.config.window.type == "vsplit" then
-		vim.cmd("vsplit")
-	else
-		vim.notify("Invalid window type: " .. M.config.window.type, vim.log.levels.ERROR)
-	end
-
 	vim.api.nvim_set_current_buf(buf)
 
 	-- Set up keymaps for the documentation window
@@ -147,4 +154,19 @@ function M.show_documentation(adapter, item)
 	vim.keymap.set("n", "<Esc>", ":close<CR>", opts)
 end
 
+--- Go to definition on chosen item
+--- @param adapter GoDocAdapter
+--- @param choice string The chosen item (package, symbol)
+--- @param picker_gotodef_fun fun()? The picker's goto_definition function
+--- @return nil
+function M.goto_definition(adapter, choice, picker_gotodef_fun)
+	if not picker_gotodef_fun then
+		vim.notify(
+			"Picker does not implement a function which can be used for showing definitions",
+			vim.log.levels.WARN
+		)
+	end
+	adapter.goto_definition(choice, picker_gotodef_fun)
+end
+
 return M

lua/godoc/pickers/fzf_lua.lua

@@ -3,7 +3,7 @@ local M = {}
 
 --- @param adapter GoDocAdapter
 --- @param config GoDocConfig
---- @param callback fun(choice: string|nil)
+--- @param callback fun(choice: GoDocCallbackData)
 function M.show(adapter, config, callback)
 	local core = require("fzf-lua.core")
 	local opts = {
@@ -12,7 +12,11 @@ function M.show(adapter, config, callback)
 		debug = false,
 		actions = {
 			["default"] = function(selected, _)
-				callback(table.concat(selected, ""))
+				callback({ type = "show_documentation", choice = table.concat(selected, "") })
+			end,
+			-- TODO: fzf lua doesn't accept 'gd' as a keymap
+			["ctrl-s"] = function(selected, _)
+				callback({ type = "goto_definition", choice = table.concat(selected, "") })
 			end,
 		},
 	}
@@ -24,4 +28,9 @@ function M.show(adapter, config, callback)
 	core.fzf_exec(adapter.get_items(), opts)
 end
 
+--- @return nil
+M.goto_definition = function()
+	require("fzf-lua").lsp_definitions()
+end
+
 return M

lua/godoc/pickers/mini.lua

@@ -3,7 +3,7 @@ local M = {}
 
 --- @param adapter GoDocAdapter
 --- @param config GoDocConfig
---- @param callback fun(choice: string|nil)
+--- @param callback fun(choice: GoDocCallbackData)
 function M.show(adapter, config, callback)
 	local minipick = require("mini.pick")
 
@@ -20,7 +20,7 @@ function M.show(adapter, config, callback)
 				vim.api.nvim_set_option_value("filetype", syntax_info.filetype, { buf = buf_id })
 			end,
 			choose = function(item)
-				callback(item)
+				callback({ type = "show_documentation", choice = item })
 			end,
 		},
 	}
@@ -32,4 +32,7 @@ function M.show(adapter, config, callback)
 	minipick.start(opts)
 end
 
+-- NOTE: goto definition is not supported in mini picker
+M.goto_definition = nil
+
 return M

lua/godoc/pickers/native.lua

@@ -2,7 +2,7 @@ local M = {}
 
 --- @param adapter GoDocAdapter
 --- @param config GoDocConfig
---- @param callback fun(choice: string|nil)
+--- @param callback fun(choice: GoDocCallbackData)
 function M.show(adapter, config, callback)
 	-- Create picker configuration
 	local opts = {
@@ -16,7 +16,12 @@ function M.show(adapter, config, callback)
 		opts = vim.tbl_deep_extend("force", opts, config.picker.native)
 	end
 
-	vim.ui.select(adapter.get_items(), opts, callback)
+	vim.ui.select(adapter.get_items(), opts, function(choice)
+		callback({ type = "show_documentation", choice = choice })
+	end)
 end
 
+-- NOTE: goto definition is not supported in native picker
+M.goto_definition = nil
+
 return M

lua/godoc/pickers/snacks.lua

@@ -3,7 +3,7 @@ local M = {}
 
 --- @param adapter GoDocAdapter
 --- @param config GoDocConfig
---- @param callback fun(choice: string|nil)
+--- @param callback fun(data: GoDocCallbackData)
 function M.show(adapter, config, callback)
 	local snacks = require("snacks")
 
@@ -35,11 +35,27 @@ function M.show(adapter, config, callback)
 				ctx.preview:reset()
 			end
 		end or nil,
+		win = {
+			input = {
+				keys = {
+					["gd"] = {
+						"goto_definition",
+						mode = { "n" },
+					},
+				},
+			},
+		},
 		actions = {
 			confirm = function(picker, item)
 				if item then
 					snacks.picker.actions.close(picker)
-					callback(item.item_name)
+					callback({ type = "show_documentation", choice = item.item_name })
+				end
+			end,
+			goto_definition = function(picker, item)
+				if item then
+					snacks.picker.actions.close(picker)
+					callback({ type = "goto_definition", choice = item.item_name })
 				end
 			end,
 		},
@@ -53,4 +69,9 @@ function M.show(adapter, config, callback)
 	snacks.picker.pick(opts)
 end
 
+--- @return nil
+function M.goto_definition()
+	require("snacks").picker.lsp_definitions()
+end
+
 return M