fix(input): cap console history growth (B3)

src/main.lua

@@ -339,6 +339,8 @@ function love.load()
   local baseconf = {
     view = viewconf,
     editor = editorconf,
+    --- console history entries kept; 0 for unlimited
+    input_history = 1000,
     autotest = autotest,
     mode = mode,
   }

src/model/input/history.lua

@@ -3,12 +3,17 @@ require('util.dequeue')
 require('util.string.string')
 require('util.debug')
 
+local DEFAULT_LIMIT = 1000
+
 --- @class History: Dequeue<string[]>
 --- @field index integer
+--- @field limit integer entry cap, 0 for unlimited
 History = class.create()
 
-function History.new()
+--- @param limit integer? entry cap; 0 means unlimited
+function History.new(limit)
   local self = Dequeue.typed('string[]')
+  self.limit = limit or DEFAULT_LIMIT
 
   setmetatable(self, {
     __index = function(t, k)
@@ -25,6 +30,7 @@ function History:remember(input)
   if string.is_non_empty_string_array(input) then
     if not self.index then
       self:append(input)
+      self:_trim()
       return true
     else
       local entry = self:get(self.index)
@@ -33,12 +39,28 @@ function History:remember(input)
       local new_s = string.unlines(new)
       if hist ~= new_s then
         self:append(input)
+        self:_trim()
       end
     end
   end
   return false
 end
 
+--- Evict oldest entries past the limit
+--- @private
+function History:_trim()
+  if self.limit == 0 then return end
+  while #self > self.limit do
+    self:pop_front()
+    if self.index then
+      self.index = self.index - 1
+      if self.index < 1 then
+        self:reset_index()
+      end
+    end
+  end
+end
+
 function History:reset_index()
   self.index = nil
 end

src/model/input/userInputModel.lua

@@ -48,7 +48,7 @@ function UserInputModel.new(cfg, eval, oneshot, custom_label)
   local self = setmetatable({
     oneshot = oneshot,
     entered = InputText(),
-    history = History(),
+    history = History(cfg.input_history),
     evaluator = eval,
     cursor = Cursor(),
     selection = InputSelection(),
@@ -354,7 +354,7 @@ end
 --- @param history boolean?
 function UserInputModel:reset(history)
   if history and self:keep_history() then
-    self.history = History()
+    self.history = History(self.cfg.input_history)
   end
   self:clear_input()
 end

tests/input/history_spec.lua

@@ -22,6 +22,39 @@ describe('history #history', function()
     history = History()
   end)
 
+  it('caps the number of entries', function()
+    local h = History(10)
+    for i = 1, 15 do
+      h:remember({ 'entry ' .. i })
+    end
+    assert.are_equal(10, h:length())
+    assert.same({ 'entry 6' }, h:get(1))
+    assert.same({ 'entry 15' }, h:get(10))
+  end)
+
+  it('treats 0 as unlimited', function()
+    local h = History(0)
+    for i = 1, 15 do
+      h:remember({ 'entry ' .. i })
+    end
+    assert.are_equal(15, h:length())
+  end)
+
+  it('defaults the limit', function()
+    assert.are_equal(1000, History().limit)
+  end)
+
+  it('keeps navigation position across eviction', function()
+    local h = History(100)
+    for i = 1, 100 do
+      h:remember({ 'e' .. i })
+    end
+    h:history_back({ '' })
+    local at = h:get(h.index)
+    h:remember({ 'typed' })
+    assert.same(at, h:get(h.index))
+  end)
+
   it('remembers', function()
     history:remember(t1)
     local h1 = { t1 }