Use the Nameable and Stringifiable mixins in the Oscillogram class

Author: thewizardplusplus

oscillogram.lua

@@ -1,3 +1,5 @@
+-- luacheck: no max comment line length
+
 ---
 -- @classmod Oscillogram
 
@@ -52,6 +54,24 @@ end
 -- @treturn Oscillogram self
 -- @treturn number always zero
 
+---
+-- @treturn tab table with instance fields
+--   (see the [luaserialization](https://github.com/thewizardplusplus/luaserialization) library)
+function Oscillogram:__data()
+  return {
+    kind = self._kind,
+    points = self._points,
+    default = self._default,
+    minimum = self._minimum,
+    maximum = self._maximum,
+  }
+end
+
+---
+-- @function __tostring
+-- @treturn string stringified table with instance fields
+--   (see the [luaserialization](https://github.com/thewizardplusplus/luaserialization) library)
+
 ---
 -- @function push
 -- @tparam number point

oscillogram_test.lua

@@ -49,6 +49,21 @@ function TestOscillogram.test_new_partial()
   luaunit.assert_equals(plot._maximum, 1)
 end
 
+function TestOscillogram.test_tostring()
+  local plot = Oscillogram:new("random", 5, 32, 23, 42)
+  local text = tostring(plot)
+
+  luaunit.assert_is_string(text)
+  luaunit.assert_equals(text, "{" ..
+    "__name = \"Oscillogram\"," ..
+    "default = 32," ..
+    "kind = \"random\"," ..
+    "maximum = 42," ..
+    "minimum = 23," ..
+    "points = { 32, 32, 32, 32, 32 }" ..
+  "}")
+end
+
 function TestOscillogram.test_update_custom()
   local plot = Oscillogram:new("custom", 0, 0.5)
   for i = 1, 5 do