Add utils.OrderedTable, make test order consistent

Also added OrderedTable tests and comment support to expect.*()

docs/changelog.txt

@@ -41,6 +41,9 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 - Core: various thread safety and memory management improvements
 - Fixed cmake build dependencies for generated header files
 
+## Lua
+- ``utils``: new ``OrderedTable`` class
+
 ================================================================================
 # 0.44.12-r1
 

library/lua/utils.lua

@@ -682,4 +682,40 @@ function addressof(obj)
     return select(2, obj:sizeof())
 end
 
+function OrderedTable()
+    -- store values in a separate table to ensure that __index and __newindex
+    -- run on every table index operation
+    local t = {}
+    local key_to_index = {}
+    local index_to_key = {}
+
+    local mt = {}
+    function mt:__index(k)
+        return t[k]
+    end
+    function mt:__newindex(k, v)
+        if not key_to_index[k] then
+            table.insert(index_to_key, k)
+            key_to_index[k] = #index_to_key
+        end
+        t[k] = v
+    end
+    function mt:__pairs()
+        return function(_, k)
+            if k then
+                k = index_to_key[key_to_index[k] + 1]
+            else
+                k = index_to_key[1]
+            end
+            if k then
+                return k, t[k]
+            end
+        end, nil, nil
+    end
+
+    local self = {}
+    setmetatable(self, mt)
+    return self
+end
+
 return _ENV

test/library/utils.lua

@@ -0,0 +1,15 @@
+local utils = require 'utils'
+
+function test.OrderedTable()
+    local t = utils.OrderedTable()
+    local keys = {'a', 'c', 'e', 'd', 'b', 'q', 58, -1.2}
+    for i = 1, #keys do
+        t[keys[i]] = i
+    end
+    local i = 1
+    for k, v in pairs(t) do
+        expect.eq(k, keys[i], 'key order')
+        expect.eq(v, i, 'correct value')
+        i = i + 1
+    end
+end

test/main.lua

@@ -1,20 +1,21 @@
 local script = require 'gui.script'
+local utils = require 'utils'
 
 local args = {...}
 local done_command = args[1]
 
 expect = {}
-function expect.true_(value)
-    return not not value
+function expect.true_(value, comment)
+    return not not value, comment, 'expected true'
 end
-function expect.false_(value)
-    return not value
+function expect.false_(value, comment)
+    return not value, comment, 'expected false'
 end
-function expect.eq(a, b)
-    return a == b
+function expect.eq(a, b, comment)
+    return a == b, comment, ('%s ~= %s'):format(a, b)
 end
-function expect.ne(a, b)
-    return a ~= b
+function expect.ne(a, b, comment)
+    return a ~= b, comment, ('%s == %s'):format(a, b)
 end
 function expect.error(func, ...)
     local ok, ret = pcall(func, ...)
@@ -32,7 +33,7 @@ end
 
 function build_test_env()
     local env = {
-        test = {},
+        test = utils.OrderedTable(),
         expect = {},
         delay = delay,
     }
@@ -43,7 +44,15 @@ function build_test_env()
     for name, func in pairs(expect) do
         env.expect[name] = function(...)
             private.checks = private.checks + 1
-            local ok, msg = func(...)
+            local ret = {func(...)}
+            local ok = table.remove(ret, 1)
+            local msg = ''
+            for _, part in pairs(ret) do
+                if part then
+                    msg = msg .. ': ' .. tostring(part)
+                end
+            end
+            msg = msg:sub(3) -- strip leading ': '
             if ok then
                 private.checks_ok = private.checks_ok + 1
             else