Fix potential memory leak issue (#41)

.eslintignore

@@ -2,6 +2,10 @@ umd/*
 dist/*
 es/*
 node_modules/*
+storybook-static/*  
 private/*
 examples/*
 .vscode/*
+__stories__/*
+__tests__/*
+

.eslintrc.json

@@ -4,6 +4,7 @@
   "parserOptions": { "ecmaVersion": 12, "sourceType": "module" },
   "rules": {
     "no-lonely-if": 0,
+    "no-console": 0,
     "no-plusplus": 0,
     "no-param-reassign": 0,
     "no-else-return": 0,

__stories__/assets/stories.css

@@ -13,19 +13,14 @@ body {
   color: var(--color-default-fg);
 }
 
-.container {
-  margin: 16px;
-  padding: 16px;
-}
-
 *,
 *::before,
 *::after {
   box-sizing: border-box;
 }
 
 .container {
-  margin: 16px;
+  margin: 0;
   padding: 16px;
   width: 100%;
   max-width: 732px;

__stories__/components/Example.svelte

@@ -56,10 +56,11 @@
     // Split the the target element(s) using the provided options
     instance = SplitType.create('.target', options)
     resizeObserver.observe(containerElement)
-    console.log(instance)
   })
 
   onDestroy(() => {
+    // Cleanup splitType instance
+    instance.revert()
     resizeObserver.disconnect()
   })
 </script>

__tests__/utils/Data.test.js

@@ -1,7 +1,54 @@
-import { Data, removeData } from '../../lib/Data'
+import * as data from '../../lib/Data'
+
+const owner = document.createElement('div')
+
+afterEach(() => {
+  data.remove(owner)
+})
 
 describe(`Data(owner)`, () => {
-  it(`Returns empty object when owner is undefined`, () => {
-    expect(Data(undefined)).toEqual({})
+  it(`data.get(undefined) returns empty object`, () => {
+    expect(data.get(undefined)).toEqual({})
+  })
+  it(`data.set(owner, key, value) works as expected`, () => {
+    // Make sure data store is empty at start of test
+    expect(data.cache).toEqual({})
+    data.set(owner, 'foo', 'bar')
+    expect(data.cache[owner[data.expando]]).toEqual({ foo: 'bar' })
+    data.set(owner, 'hello', 'world')
+    expect(data.cache[owner[data.expando]]).toEqual({
+      foo: 'bar',
+      hello: 'world',
+    })
+  })
+  it(`data.set(owner, objectMap) works as expected`, () => {
+    // Make sure data store is empty at start of test
+    expect(data.cache).toEqual({})
+    data.set(owner, {
+      foo: 'bar',
+      hello: 'world',
+    })
+    expect(data.cache[owner[data.expando]]).toEqual({
+      foo: 'bar',
+      hello: 'world',
+    })
+  })
+
+  it(`data.get(owner) returns data object `, () => {
+    // Make sure data store is empty at start of test
+    expect(data.get(owner)).toEqual({})
+    // Set multiple properties by passing an object as the second arg
+    data.set(owner, {
+      foo: 'bar',
+      hello: 'world',
+    })
+    // Set an additional property using the (owner, key, value) syntax
+    data.set(owner, 'other', 'value')
+    // data.get(owner) should return an object with the the expected props
+    expect(data.get(owner)).toEqual({
+      foo: 'bar',
+      hello: 'world',
+      other: 'value',
+    })
   })
 })

lib/Data.js

@@ -1,4 +1,9 @@
 import isObject from './utils/isObject'
+import { entries } from './utils/object'
+
+export const expando = `_splittype`
+export const cache = {}
+let uid = 0
 
 /**
  * Stores data associated with DOM elements or other objects. This is a
@@ -23,37 +28,52 @@ import isObject from './utils/isObject'
  * @param {string} key
  * @param {any} value
  */
-export function Data(owner, key, value) {
-  let data = {}
-  let id = null
-
-  if (isObject(owner)) {
-    id = owner[Data.expando] || (owner[Data.expando] = ++Data.uid)
-    data = Data.cache[id] || (Data.cache[id] = {})
+export function set(owner, key, value) {
+  if (!isObject(owner)) {
+    console.warn('[data.set] owner is not an object')
+    return null
   }
-  // Get data
+  const id = owner[expando] || (owner[expando] = ++uid)
+  const data = cache[id] || (cache[id] = {})
+
   if (value === undefined) {
-    if (key === undefined) {
-      return data
+    if (!!key && Object.getPrototypeOf(key) === Object.prototype) {
+      cache[id] = { ...data, ...key }
     }
-    return data[key]
-  }
-  // Set data
-  else if (key !== undefined) {
+  } else if (key !== undefined) {
     data[key] = value
-    return value
   }
+  return value
 }
 
-Data.expando = `splitType${new Date() * 1}`
-Data.cache = {}
-Data.uid = 0
+export function get(owner, key) {
+  const id = isObject(owner) ? owner[expando] : null
+  const data = (id && cache[id]) || {}
+  if (key === undefined) {
+    return data
+  }
+  return data[key]
+}
 
-// Remove all data associated with the given element
-export function RemoveData(element) {
-  const id = element && element[Data.expando]
+/**
+ * Remove all data associated with the given element
+ */
+export function remove(element) {
+  const id = element && element[expando]
   if (id) {
     delete element[id]
-    delete Data.cache[id]
+    delete cache[id]
   }
 }
+
+/**
+ * Remove all temporary data from the store.
+ */
+export function cleanup() {
+  entries(cache).forEach(([id, { isRoot, isSplit }]) => {
+    if (!isRoot || !isSplit) {
+      cache[id] = null
+      delete cache[id]
+    }
+  })
+}