Meh I'll figure out submodules later

.config/nvim/pack/tree/start/plenary.nvim/lua/luassert/state.lua

@@ -0,0 +1,127 @@
+-- maintains a state of the assert engine in a linked-list fashion
+-- records; formatters, parameters, spies and stubs
+
+local state_mt = {
+  __call = function(self)
+    self:revert()
+  end
+}
+
+local spies_mt = { __mode = "kv" }
+
+local nilvalue = {} -- unique ID to refer to nil values for parameters
+
+-- will hold the current state
+local current
+
+-- exported module table
+local state = {}
+
+------------------------------------------------------
+-- Reverts to a (specific) snapshot.
+-- @param self (optional) the snapshot to revert to. If not provided, it will revert to the last snapshot.
+state.revert = function(self)
+  if not self then
+    -- no snapshot given, so move 1 up
+    self = current
+    if not self.previous then
+      -- top of list, no previous one, nothing to do
+      return
+    end
+  end
+  if getmetatable(self) ~= state_mt then error("Value provided is not a valid snapshot", 2) end
+
+  if self.next then
+    self.next:revert()
+  end
+  -- revert formatters in 'last'
+  self.formatters = {}
+  -- revert parameters in 'last'
+  self.parameters = {}
+  -- revert spies/stubs in 'last'
+  for s,_ in pairs(self.spies) do
+    self.spies[s] = nil
+    s:revert()
+  end
+  setmetatable(self, nil) -- invalidate as a snapshot
+  current = self.previous
+  current.next = nil
+end
+
+------------------------------------------------------
+-- Creates a new snapshot.
+-- @return snapshot table
+state.snapshot = function()
+  local new = setmetatable ({
+    formatters = {},
+    parameters = {},
+    spies = setmetatable({}, spies_mt),
+    previous = current,
+    revert = state.revert,
+  }, state_mt)
+  if current then current.next = new end
+  current = new
+  return current
+end
+
+
+--  FORMATTERS
+state.add_formatter = function(callback)
+  table.insert(current.formatters, 1, callback)
+end
+
+state.remove_formatter = function(callback, s)
+  s = s or current
+  for i, v in ipairs(s.formatters) do
+    if v == callback then
+      table.remove(s.formatters, i)
+      break
+    end
+  end
+  -- wasn't found, so traverse up 1 state
+  if s.previous then
+    state.remove_formatter(callback, s.previous)
+  end
+end
+
+state.format_argument = function(val, s, fmtargs)
+  s = s or current
+  for _, fmt in ipairs(s.formatters) do
+    local valfmt = fmt(val, fmtargs)
+    if valfmt ~= nil then return valfmt end
+  end
+  -- nothing found, check snapshot 1 up in list
+  if s.previous then
+    return state.format_argument(val, s.previous, fmtargs)
+  end
+  return nil -- end of list, couldn't format
+end
+
+
+--  PARAMETERS
+state.set_parameter = function(name, value)
+  if value == nil then value = nilvalue end
+  current.parameters[name] = value
+end
+
+state.get_parameter = function(name, s)
+  s = s or current
+  local val = s.parameters[name]
+  if val == nil and s.previous then
+    -- not found, so check 1 up in list
+    return state.get_parameter(name, s.previous)
+  end
+  if val ~= nilvalue then
+    return val
+  end
+  return nil
+end
+
+--  SPIES / STUBS
+state.add_spy = function(spy)
+  current.spies[spy] = true
+end
+
+state.snapshot()  -- create initial state
+
+return state