From 63fbc9ef128fcbd003b90ecc77f7e6d1c84c7a0f Mon Sep 17 00:00:00 2001
From: Jon Michael Aanes <jonjmaa@gmail.com>
Date: Sun, 29 Oct 2017 10:16:16 +0100
Subject: [PATCH] Added support for short constant values, and better
 names/descriptions of functions.

---
 assert-gooder.lua           | 24 ++++++++++++++++++++++--
 test/test_assert-gooder.lua | 29 ++++++++++++++++++++++++-----
 2 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/assert-gooder.lua b/assert-gooder.lua
index fba35ea..7405e37 100644
--- a/assert-gooder.lua
+++ b/assert-gooder.lua
@@ -62,6 +62,22 @@ local function get_variable (var_name, level)
 	return getfenv(level + 1)[var_name], 'global'
 end
 
+local function get_function_name (call_info)
+	--
+	if call_info.name then  return  string.format('\'%s\'', call_info.name)  end
+	--
+	local where = nil
+	if call_info.source:find '^@' then
+		where = 'at '..call_info.short_src..':'..call_info.linedefined
+	elseif call_info.short_src:find '^%[string' then
+		where = 'from loaded string'
+	else
+		error 'not yet implemented'
+	end
+	--
+	return string.format('the anonymous function %s', where)
+end
+
 local function get_value_of_string (string_str)
 	if string_str:sub(1, 1) == '"' or string_str:sub(1, 1) == '\'' then
 		return string_str:sub(2, -2)
@@ -82,7 +98,7 @@ local function get_variable_and_prefix (gotten_name, level)
 	assert(type(level) == 'number')
 	--
 	local gotten_val, var_scope, in_func  =  get_variable(gotten_name, level + 1)
-	local func_name = (in_func == '' and ' to anonymous function') or in_func and (' to \''..in_func..'\'') or ''
+	local func_name = in_func and (' to '..get_function_name(debug.getinfo(level + 1))) or ''
 	return gotten_val, ('assertion failed! bad %s \'%s\'%s'):format(var_scope, gotten_name, func_name)
 end
 
@@ -146,8 +162,12 @@ return function (condition)
 	elseif #tokens == 1 and tokens[1].token == 'IDENTIFIER' then
 		local gotten_val, prefix  =  get_variable_and_prefix(tokens[1].text, 2)
 		error(('%s (truthy expected, but got %s)'):format(prefix, fmt_val(gotten_val)), 2)
+	elseif #tokens == 1 and (tokens[1].token == 'NIL' or tokens[1].token == 'FALSE') then
+		local func_name  =  get_function_name(call_info)
+		error(('assertion failed! this assert will always fail, as it\'s body is `%s`. assumingly this should be an unreachable part of %s'):format(body_text, func_name), 2)
+	elseif #tokens == 1 then
+		error 'should be unreachable!'
 	else
-		print(require'pretty'(tokens))
 		error(('assertion failed! expression `%s` evaluated to %s'):format(body_text, condition), 2)
 	end
 end
diff --git a/test/test_assert-gooder.lua b/test/test_assert-gooder.lua
index 7a34bb9..002b61b 100644
--- a/test/test_assert-gooder.lua
+++ b/test/test_assert-gooder.lua
@@ -31,10 +31,12 @@ SUITE:addTest('global variable', function ()
 end)
 
 SUITE:addTest('argument to anon function', function ()
-	local _, msg = pcall(function (a)
-		assert(type(a) == 'string')
-	end, 2)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad argument #1 \'a\' to anonymous function (string expected, but got number: 2)', msg)
+	local _, msg = pcall(function()
+		(function (a)
+			assert(type(a) == 'string')
+		end)(2)
+	end)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-3)..': '..'assertion failed! bad argument #1 \'a\' to the anonymous function at ./test/test_assert-gooder.lua:'..curline(-4)..' (string expected, but got number: 2)', msg)
 end)
 
 SUITE:addTest('argument to named function', function ()
@@ -50,7 +52,7 @@ end)
 SUITE:addTest('can improve asserts in loaded strings too', function ()
 	local func = loadstring "return function(a) assert(type(a) == 'string')  end" ()
 	local _, msg = pcall(setfenv(func, getfenv()), 42)
-	assert_equal('[string "return function(a) assert(type(a) == \'string\'..."]:1: '..'assertion failed! bad argument #1 \'a\' to anonymous function (string expected, but got number: 42)', msg)
+	assert_equal('[string "return function(a) assert(type(a) == \'string\'..."]:1: '..'assertion failed! bad argument #1 \'a\' to the anonymous function from loaded string (string expected, but got number: 42)', msg)
 end)
 
 SUITE:addTest('really complicated expression', function ()
@@ -107,6 +109,23 @@ end, { data = {
 	{ '42',   	'expected anything other than number 42, but got 42' },
 }})
 
+SUITE:addTest('constant false', function ()
+	local function f ()
+		assert(false)
+	end
+	local _, msg  =  pcall(function() f() end)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-3)..': '..'assertion failed! this assert will always fail, as it\'s body is `false`. assumingly this should be an unreachable part of \'f\'', msg)
+end)
+
+SUITE:addTest('constant nil', function ()
+	local _, msg  =  pcall(function ()
+		assert(nil)
+	end)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! this assert will always fail, as it\'s body is `nil`. assumingly this should be an unreachable part of the anonymous function at ./test/test_assert-gooder.lua:'..curline(-3), msg)
+end)
+
+
+
 --------------------------------------------------------------------------------
 
 return SUITE