Module:Module introspection

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This module should not be invoked directly; use its corresponding template instead: Template:Module introspection.

Module:Module introspection is ready for use. This message indicates that a module is ready for use, or has recently been repaired. This message may be removed once this module has been used on several pages or once it is verified to work as intended. Details: Edge-case observation still ongoing. Currently cannot detect data provided by a module.

---

-- This module follows [[User:Ganaram inukshuk/Provisional style guide for Lua]]
local getArgs = require("Module:Arguments").getArgs
local p = {}

-- TODO: add additional functions:
-- - Determine whether a main function exists, as _main or a function of the
--   same name as the module with an underscore.
-- - Determine whether a wrapper exists, as main or a function of the same name
--   as the module, without an underscore.
-- - If the wrapper exists without _main, the wrapper is assumed to be the main
--   function.
-- - If both wrapper and _main exists, _main is the main function.
-- - If neither function exists, then the module is a metamodule, a module that
--   generally provides functionality to other modules.

-- TODO: bugfix dependency usage
-- The following snippet should detect use of any dependency, but it should be
-- cross-referenced with the found dependencies
--[[
for match in code:gmatch("([_%a][_%w%.]*)%s*%(") do
    print(match)
end
]]--

-- PROPOSED ALGORITHM FOR FINDING FUNCTIONS OF DEPENDENCIES
-- - Find every unique function call in the template, filtering out all function
--   calls that do not correspond to a dependency. For a dependency included as
--   local dep = require("Module:Dependency"), the module is called "Dependency"
--   and is called "dep" throughout the code. Function calls involving this
--   dependency will have "dep" as part of the name, as dep(), dep.func(), or 
--   with any number of dots (dep.utils.formatter.func()), but zero or one dots
--   is typical.
-- - For each dependency name, place each function call with that dependency's
--   name in a table of function calls.
-- - Inspect each dependency's table. If there is at least one function call in
--   that table, then that dependency is used. If not, then that module is not
--   used.
-- - If function calls match the name of the dependency "dep", then either the
--   module returned a function or the code require("Module:Dep").func selected
--   only one function. If it's the former, then the module IS the function. If
--   it's the latter, then func from require("Module:Dep").func is the function.
--   In either case, if no function calls called "dep" are found, then the
--   dependency "dep" was not used.

-- Inspects a module for its functions, its dependencies, and the functions used
-- from those dependencies.

-- Helper function
-- Blanks comments but preserves line numbers
function p.strip_comments(code_unstripped)
	if not code_unstripped then return "" end

	local lines = {}
	local in_multiline = false
	local end_pattern

	for line in code_unstripped:gmatch("([^\n]*)\n") do
		local processed = line
	
		if in_multiline then
			-- Check for end of multi-line comment first
			local s, e = processed:find(end_pattern)
			if s then
				in_multiline = false
				-- Replace only the comment part with spaces
				processed = string.rep(" ", e) .. processed:sub(e + 1)
			else
				-- Entire line is inside comment
				processed = processed:gsub(".", " ")
			end
		else
			local start_eq = processed:match("%-%-%[(=*)%[")
			if start_eq then
				in_multiline = true
				end_pattern = "%]" .. start_eq .. "%]"
				-- Blank from the start of comment to the end of line
				local s, e = processed:find("%-%-%[" .. start_eq .. "%[")
				if s then
					processed = string.rep(" ", #processed)
				end
			else
				processed = processed:gsub("%-%-.*", function(s)
					return string.rep(" ", #s)
				end)
			end
		end
	
		table.insert(lines, processed)
	end

	return table.concat(lines, "\n")
end

-- Helper function
-- Find dependencies for a module, given a preprocessed module's code, then use
-- that information to find every function call for each dependency.
function p.find_dependencies(code)
	local deps = {}		-- Dependencies used
	
	-- STEP 1
	-- For each require line, get the dependency name (dep), the variable used
	-- for that dependency (var), and, if applicable, the function used from
	-- that dependency.
	-- A require line looks like: local var = require("Module:Dependency").func,
	-- where ".func" is optional.
	for var, dep, func in code:gmatch([[local%s+([%w_]+)%s*=%s*require%(%s*["']([^"']+)["']%s*%)%.?([%w_%.]*)]]) do
		if func == "" then func = nil end	-- If func was blank, replace with nil instead
		deps[var] = { 
			["dep"] = dep,
			["funcs"] = { },
			["direct_func"] = func		-- For detecting whether one function out of a package was used
		}
	end
	
	-- STEP 2
	-- For each dependency found, find all function calls that involve that
	-- dependency, as var.func(), or var(), without duplicates. If at least one
	-- function call was found, then that module is used.
	for var, info in pairs(deps) do
		local seen  = {}  -- For detecting whether a function call was already found
		local funcs = {}  -- For tracking all found function calls
	
		if info["direct_func"] then
			-- SPECIAL CASE 1: only one function imported from a package
			if code:match(var .. "%s*%(") then
				funcs = { info["direct_func"] }
			end
		else
			-- EXPECTED CASE: multiple functions from package used
			for func in code:gmatch(var .. "%.([%w_%.]+)%s*%(") do
				if not seen[func] then
					seen[func] = true
					table.insert(funcs, func)
				end
			end
	
			-- SPECIAL CASE 2: module returns a function and is callable
			if #funcs == 0 and code:match(var .. "%s*%(") then
				funcs = { var }
			end
		end
	
		info["funcs"] = funcs
	end

	return deps
end

-- Helper function
-- Given the output of the above function, create a mediawiki table
function p.make_dependency_table(deps)
	local lines = {}

	-- Table header
	table.insert(lines, '{| class="wikitable sortable left-1 left-2"')
	table.insert(lines, '! Variable')
	table.insert(lines, '! Module')
	table.insert(lines, '! Functions used')

	for var, info in pairs(deps) do
		local funcs_text
		if #info.funcs == 0 then
			funcs_text = "''dependency not used''"
		else
			funcs_text = table.concat(info.funcs, '<br />')
		end

		table.insert(lines, '|-')
		table.insert(lines, '| ' .. var)
		table.insert(lines, '| ' .. info.dep)
		table.insert(lines, '| ' .. funcs_text)
	end

	-- Table footer
	table.insert(lines, '|}')

	-- Join all lines into a single string
	return table.concat(lines, '\n')
end


-- Helper function
-- Find functions provided by a module, ignoring nested/local functions
function p.find_functions(code)

	-- Iterate through file and find each function and the line found at
	local funcs = {}
	if code then
		local line_num = 0
		for line in code:gmatch("([^\n]*)\n?") do		-- Make sure gmatch does not skip blank lines
			line_num = line_num + 1

			-- Match functions defined as function p.name(
			local name = line:match("function%s+[%w_]+%.([%w_]+)%s*%(")
			if name then
				table.insert(funcs, {name = name, line = line_num})
			end

			-- Match functions defined as p.name = function(
			name = line:match("[%w_]+%.([%w_]+)%s*=%s*function%s*%(")
			if name then
				table.insert(funcs, {name = name, line = line_num})
			end
		end
	end

	return funcs
end

-- Helper function
-- Lists module's own functions; requires module name to produce links to each
-- function.
function p.make_function_table(module_name, module_functions, main_function)
	
	-- Collapse table if it's larger than 20 lines
	local func_class = "wikitable sortable mw-collapsible"
	if #module_functions > 20 then
		func_class = func_class .. " mw-collapsed"
	end
	
	local func_lines = {}
	--table.insert(func_lines, string.format("'''Module:%s''' provides %d function(s):", module_name, #module_functions))
	table.insert(func_lines, "{| class=\"" .. func_class .. "\"")
	table.insert(func_lines, "|+ Functions provided by this module")
	table.insert(func_lines, "! Function")
	table.insert(func_lines, "! Line")

	for _, f in ipairs(module_functions) do
		local link = string.format("[[Module:%s#L-%d|%s]]", module_name, f.line, f.name)
		
		-- If the function is the main function, add "main" to that cell
		if f.name == main_function then
			link = link .. " '''(main)'''"
		end
		
		table.insert(func_lines, "|-")
		table.insert(func_lines, "| " .. link)
		table.insert(func_lines, "| " .. f.line)
	end
	table.insert(func_lines, "|}")
	
	return func_lines
end

-- Helper function: determines whether module has a main function; if it does,
-- it indicates that it's not a library function and provides specific function-
-- ality, usually for a template.

-- Main function; to be called by wrapper
function p._module_introspection(args)
	local args = args or {}
	local module_name   = args["module_name"  ]
	local main_function = args["main_function"]
	
	-- Preprocess module and blank-out comments
	local title = mw.title.new('Module:' .. module_name)
	local code = title:getContent()
	code = p.strip_comments(code)		-- Blank-out comments
	
	-- Get dependencies and their functions used, then build a table
	local module_deps = p.find_dependencies(code)
	local dep_lines = p.make_dependency_table(module_deps)

	-- Get module's functions, then build a table using that information
	local module_functions = p.find_functions(code)
	local func_lines = p.make_function_table(module_name, module_functions, main_function)

	-- Return the tables as strings
	local summary = string.format("'''Introspection summary:''' Module:%s provides %d functions(s).", module_name, #module_functions)
	return summary .. "\n" .. table.concat(func_lines, "\n") .. "\n" .. table.concat(dep_lines, "\n")
end


-- Wrapper function for modules
function p.module_introspection(frame)
	-- Extract arguments using getArgs
	local args = getArgs(frame) or {}

	-- Get module name from arguments, or default to current page
	local module_name = args["module_name"] or mw.title.getCurrentTitle().text

	-- Strip trailing "/doc" if the template is used on a documentation subpage
	module_name = module_name:gsub("/doc$", "")
	
	-- Normalize module name so it can be used to find the main function, which
	-- is assumed to be the same name as the module. Module assumes snake_case
	-- is used for function names. (If this fails, it can be entered manually.)
	local normalized_name = module_name:gsub("[^%w]", "_"):lower()
	local main_function = args["main_function"] or "_" .. normalized_name

	-- Return
	return p._module_introspection({
		["module_name"]   = module_name,
		["main_function"] = main_function,
	})
end

function p.tester()
	local sample_code_1 = [[
	-- Package of functions (used)
	local util = require("Module:Util")
	util.trim(" x ")
	util.str.pad("y")
	
	-- Module returning a single function (used)
	local makeMessage = require("Module:Message")
	makeMessage("hello")
	
	-- Module returning a table but only one function imported (used)
	local trim = require("Module:StringUtils").trim
	trim(" world ")
	]]
	
	local sample_code_2 = [[
	-- Package of functions (used)
	local util = require("Module:Util")
	util.trim(" x ")
	util.str.pad("y")
	
	-- Module returning a single function (used)
	local makeMessage = require("Module:Message")
	makeMessage("hello")
	
	-- Module returning a table but only one function imported (used)
	local trim = require("Module:StringUtils").trim
	trim(" world ")
	
	-- UNUSED MODULES
	
	-- Unused package of functions
	local mathx = require("Module:MathX")
	
	-- Unused module returning a single function
	local sendNotification = require("Module:Notify")
	
	-- Unused single imported function
	local pad = require("Module:Util").pad
	]]
	
	local title = mw.title.new("Module:Infobox MOS")
	local code = title:getContent()
	code = p.strip_comments(code)		-- Blank-out comments
	
	return p.make_dependency_table(p.find_dependencies(code))
end

return p