More info, and more general.

assert-gooder.lua

@@ -39,6 +39,41 @@ local function get_value_token (token)
     assert(false)
 end
 
+local function get_variable (var_name, info)
+    --
+    assert(type(var_name) == 'string')
+    assert(type(info)     == 'table')
+
+    -- Local
+    if info.locals[var_name] then
+        local var_info = info.locals[var_name]
+        return var_info[1], var_info[2] and ('argument #'..var_info[3]) or 'local', info.name or var_info[2] and ''
+    end
+
+    -- Up-value
+    local index = 0
+    repeat
+        index = index + 1
+        local name, val  =  debug.getupvalue(info.func, index)
+        if name == var_name then  return val, 'upvalue'  end
+    until not name
+
+    -- Global
+    return getfenv(info.func)[var_name], 'global'
+end
+
+local function get_value_from_lvalue (lvalue, info)
+    assert(type(lvalue) == 'table')
+    assert(type(info)   == 'table')
+
+    -- Base value
+    local value, var_scope, in_func  =  get_variable(lvalue[1], info)
+    -- Sub value
+    for i = 2, #lvalue do  value = value[lvalue[i].value]  end
+    --
+    return value, var_scope, in_func
+end
+
 --------------------------------------------------------------------------------
 -- Parsing
 
@@ -51,15 +86,15 @@ local function parse (tokens)
         return {
             exp   = 'COMPARE',
             binop = 'EQ',
-            left  = { exp = 'CALL', callee = get_value_token(tokens[1]), get_value_token(tokens[3]) },
+            [1]   = { exp = 'CALL', get_value_token(tokens[1]), get_value_token(tokens[3]) },
-            right = get_value_token(tokens[6]),
+            [2]   = get_value_token(tokens[6]),
         }
     elseif #tokens == 3 and VALUE_TOKEN[tokens[1].token] and COMPARE_BINOP[tokens[2].token] and VALUE_TOKEN[tokens[3].token] then
         return {
             exp     = 'COMPARE',
             binop   = tokens[2].token,
-            left    = get_value_token(tokens[1]),
+            [1]     = get_value_token(tokens[1]),
-            right   = get_value_token(tokens[3])
+            [2]     = get_value_token(tokens[3])
         }
     elseif #tokens == 3 and tokens[1].token == 'IDENTIFIER' and tokens[2].token == 'DOT' and tokens[3].token == 'IDENTIFIER' then
         return { exp = 'LVALUE', tokens[1].text, { exp = 'STRING', value = tokens[3].text } }
@@ -72,8 +107,13 @@ local function parse (tokens)
     end
 end
 
-local function populate_ast_with_semantics (node, env)
+local function populate_ast_with_semantics (node, info)
-
+    if type(node) ~= 'table' then  return  end
+    for i = 1, #node do  populate_ast_with_semantics(node[i], info)  end
+    --
+    if node.exp == 'LVALUE' then
+        node.value = get_value_from_lvalue(node, info)
+    end
 end
 
 --------------------------------------------------------------------------------
@@ -112,29 +152,6 @@ local function get_assert_body (call_info)
     return lexer:lex(text), text
 end
 
-local function get_variable (var_name, info)
-    --
-    assert(type(var_name) == 'string')
-    assert(type(info)     == 'table')
-
-    -- Local
-    if info.locals[var_name] then
-        local var_info = info.locals[var_name]
-        return var_info[1], var_info[2] and ('argument #'..var_info[3]) or 'local', info.name or var_info[2] and ''
-    end
-
-    -- Up-value
-    local index = 0
-    repeat
-        index = index + 1
-        local name, val  =  debug.getupvalue(info.func, index)
-        if name == var_name then  return val, 'upvalue'  end
-    until not name
-
-    -- Global
-    return getfenv(info.func)[var_name], 'global'
-end
-
 local function get_function_name (call_info)
     --
     if call_info.name then  return  string.format('\'%s\'', call_info.name)  end
@@ -170,10 +187,7 @@ end
 local function get_variable_and_prefix (lvalue, call_info)
     assert(type(lvalue) == 'table' and lvalue.exp == 'LVALUE')
     --
-    local base_value, var_scope, in_func  =  get_variable(lvalue[1], call_info)
+    local value, var_scope, in_func = get_value_from_lvalue(lvalue, call_info)
-    -- Determine value of variable
-    local value = base_value
-    for i = 2, #lvalue do  value = value[lvalue[i].value]  end
     --
     local func_name = in_func and (' to '..get_function_name(call_info)) or ''
     return value, ('bad %s%s'):format(fmt_lvalue(lvalue, var_scope), func_name)
@@ -189,9 +203,10 @@ local COMPLEX_TYPES = {
     ['table']       = true,
     ['userdata']    = true,
     ['cdata']       = true,
+    ['function']    = true,
 }
 
-local function fmt_with_type (val)
+local function fmt_val_with_type (val)
     -- Primitive values ARE their type, and don't need the annotation.
     if PRIMITIVE_VALUES[type(val)] then  return tostring(val)  end
     -- Complex types are already formatted with some type information.
@@ -205,25 +220,26 @@ end
 local function determine_error_message (call_info, msg, condition)
     local tokens, body_text = get_assert_body(call_info)
     local ast = parse(tokens)
+    populate_ast_with_semantics(ast, call_info)
 
     msg[1] = ('expression `%s` evaluated to %s'):format(body_text, condition)
     local var_prefix = function(token)  return get_variable_and_prefix(token, call_info)  end
 
     if not ast then  return nil
-    elseif ast.exp == 'COMPARE' and ast.binop == 'EQ' and ast.left.exp == 'CALL' and ast.left.callee.exp == 'LVALUE' and ast.left.callee[1] == 'type' then
+    elseif ast.exp == 'COMPARE' and ast.binop == 'EQ' and ast[1].exp == 'CALL' and ast[1][1].exp == 'LVALUE' and ast[1][1][1] == 'type' then
-        local gotten_val, prefix  =  var_prefix(ast.left[1])
+        local gotten_val, prefix  =  var_prefix(ast[1][2])
-        msg[1] = ('%s (%s expected, but got %s: %s)'):format(prefix, ast.right.value, type(gotten_val), fmt_val(gotten_val))
+        msg[1] = ('%s (%s expected, but got %s)'):format(prefix, ast[2].value, fmt_val_with_type(gotten_val))
 
     elseif ast.exp == 'COMPARE' and ast.binop == 'EQ' then
-        local gotten_value, prefix  = var_prefix(ast.left)
+        local gotten_value, prefix  = var_prefix(ast[1])
-        local expected_value  = ast.right.value
+        local expected_value  = ast[2].value
-        local type_annotation = (type(expected_value) == type(gotten_value)) and '' or (' '..type(gotten_value))
+        local fmt_gotten = (type(expected_value) == type(gotten_value)) and fmt_val or fmt_val_with_type
-        msg[1] = ('%s (%s expected, but got%s: %s)'):format(prefix, fmt_with_type(expected_value), type_annotation, fmt_val(gotten_value))
+        msg[1] = ('%s (%s expected, but got %s)'):format(prefix, fmt_val_with_type(expected_value), fmt_gotten(gotten_value))
 
     elseif ast.exp == 'COMPARE' and ast.binop == 'NEQ' then
-        local gotten_val, prefix  = var_prefix(ast.left)
+        local gotten_val, prefix  = var_prefix(ast[1])
-        local expected_value = ast.right.value
+        local expected_value = ast[2].value
-        msg[1] = ('%s (expected anything other than %s, but got %s)'):format(prefix, fmt_with_type(expected_value), fmt_val(gotten_val))
+        msg[1] = ('%s (expected anything other than %s, but got %s)'):format(prefix, fmt_val_with_type(expected_value), fmt_val(gotten_val))
 
     elseif ast.exp == 'LVALUE' then
         local gotten_val, prefix  =  var_prefix(ast)

test/test_assert-gooder.lua

@@ -11,7 +11,7 @@ SUITE:addTest('local variable', function ()
 		local a = 2
 		assert(type(a) == 'string')
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (string expected, but got number: 2)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (string expected, but got number 2)', msg)
 end)
 
 SUITE:addTest('upvalue variable', function ()
@@ -19,7 +19,7 @@ SUITE:addTest('upvalue variable', function ()
 	local _, msg  =  pcall(function ()
 		assert(type(a) == 'string')
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad upvalue \'a\' (string expected, but got number: 2)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad upvalue \'a\' (string expected, but got number 2)', msg)
 end)
 
 SUITE:addTest('global variable', function ()
@@ -27,7 +27,7 @@ SUITE:addTest('global variable', function ()
 	local _, msg  =  pcall(function ()
 		assert(type(a) == 'string')
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad global \'a\' (string expected, but got number: 2)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad global \'a\' (string expected, but got number 2)', msg)
 end)
 
 SUITE:addTest('argument to anon function', function ()
@@ -36,7 +36,7 @@ SUITE:addTest('argument to anon function', function ()
 			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)
+	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 ()
@@ -44,7 +44,7 @@ SUITE:addTest('argument to named function', function ()
 		assert(type(a) == 'string')
 	end
 	local _, msg = pcall(function () f(2) end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-3)..': '..'assertion failed! bad argument #1 \'a\' to \'f\' (string expected, but got number: 2)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-3)..': '..'assertion failed! bad argument #1 \'a\' to \'f\' (string expected, but got number 2)', msg)
 end)
 
 
@@ -53,7 +53,7 @@ SUITE:addTest('indexing', function ()
 		local a = { b = 39 }
 		assert(type(a.b) == 'string')
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad key "b" in local \'a\' (string expected, but got number: 39)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad key "b" in local \'a\' (string expected, but got number 39)', msg)
 end)
 
 SUITE:addTest('subscript constant', function ()
@@ -61,7 +61,7 @@ SUITE:addTest('subscript constant', function ()
 		local a = { 4, 2, 3, 6 }
 		assert(type(a.b) == 'string')
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad key 2 in local \'a\' (string expected, but got number: 2)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad key 2 in local \'a\' (string expected, but got number 2)', msg)
 end)
 
 SUITE:addTest('subscript variable', function ()
@@ -69,7 +69,7 @@ SUITE:addTest('subscript variable', function ()
 		local a, i = { 4, 2, 3, 6 }, 2
 		assert(type(a.b) == 'string')
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad key 2 in local \'a\' (string expected, but got number: 2)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad key 2 in local \'a\' (string expected, but got number 2)', msg)
 end)
 
 --------------------------------------------------------------------------------
@@ -77,7 +77,7 @@ 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 the anonymous function from loaded string (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 ()
@@ -96,7 +96,7 @@ SUITE:addTest('compare values', function ()
 		local a = 2
 		assert(a == 4)
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (number 4 expected, but got: 2)', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (number 4 expected, but got 2)', msg)
 end)
 
 SUITE:addTest('compare values across types', function ()
@@ -104,7 +104,7 @@ SUITE:addTest('compare values across types', function ()
 		local a = "hi"
 		assert(a == 4)
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (number 4 expected, but got string: "hi")', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (number 4 expected, but got string "hi")', msg)
 end)
 
 SUITE:addTest('is nil', function ()
@@ -112,7 +112,7 @@ SUITE:addTest('is nil', function ()
 		local a = "hi"
 		assert(a == nil)
 	end)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (nil expected, but got string: "hi")', msg)
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'a\' (nil expected, but got string "hi")', msg)
 end)
 
 SUITE:addTest('truthy', function ()
@@ -175,12 +175,11 @@ SUITE:addTest('constant nil', function ()
 end)
 
 SUITE:addTest('function as type argument', function ()
+	local f = function()  end
 	local _, msg  =  pcall(function ()
-		local f = function()  end
 		assert(type(f) == 'string')
 	end)
-	-- TODO: How do we test this?
+	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad upvalue \'f\' (string expected, but got '..tostring(f)..')', msg)
-	assert_equal('./test/test_assert-gooder.lua:'..curline(-2)..': '..'assertion failed! bad local \'f\' (string expected, but got function)', msg)
 end)
 
 --------------------------------------------------------------------------------