Support empty string for maxlength

An input's maxlength can be an empty string, which should NOT limit typing.

src/__tests__/type.js

@@ -292,6 +292,44 @@ test('honors maxlength', () => {
   `)
 })
 
+test('honors maxlength="" as if there was no maxlength', () => {
+  const {element, getEventSnapshot} = setup('<input maxlength="" />')
+  userEvent.type(element, '123')
+
+  expect(getEventSnapshot()).toMatchInlineSnapshot(`
+    Events fired on: input[value="123"]
+
+    input[value=""] - pointerover
+    input[value=""] - pointerenter
+    input[value=""] - mouseover: Left (0)
+    input[value=""] - mouseenter: Left (0)
+    input[value=""] - pointermove
+    input[value=""] - mousemove: Left (0)
+    input[value=""] - pointerdown
+    input[value=""] - mousedown: Left (0)
+    input[value=""] - focus
+    input[value=""] - focusin
+    input[value=""] - pointerup
+    input[value=""] - mouseup: Left (0)
+    input[value=""] - click: Left (0)
+    input[value=""] - keydown: 1 (49)
+    input[value=""] - keypress: 1 (49)
+    input[value="1"] - input
+      "{CURSOR}" -> "1{CURSOR}"
+    input[value="1"] - keyup: 1 (49)
+    input[value="1"] - keydown: 2 (50)
+    input[value="1"] - keypress: 2 (50)
+    input[value="12"] - input
+      "1{CURSOR}" -> "12{CURSOR}"
+    input[value="12"] - keyup: 2 (50)
+    input[value="12"] - keydown: 3 (51)
+    input[value="12"] - keypress: 3 (51)
+    input[value="123"] - input
+      "12{CURSOR}" -> "123{CURSOR}"
+    input[value="123"] - keyup: 3 (51)
+  `)
+})
+
 test('honors maxlength with existing text', () => {
   const {element, getEventSnapshot} = setup(
     '<input value="12" maxlength="2" />',

src/utils/edit/calculateNewValue.ts

@@ -16,7 +16,10 @@ export function calculateNewValue(
 
   // can't use .maxLength property because of a jsdom bug:
   // https://github.com/jsdom/jsdom/issues/2927
-  const maxLength = Number(element.getAttribute('maxlength') ?? -1)
+  //
+  // '' is a valid value in DOM with the same meaning as -1, not 0 => use ||
+  // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
+  const maxLength = Number(element.getAttribute('maxlength') || -1)
 
   let newValue: string, newSelectionStart: number