feat(runtime-dom): v-model directive runtime

packages/shared/src/index.ts

@@ -64,3 +64,44 @@ export const hyphenate = (str: string): string => {
 export const capitalize = (str: string): string => {
   return str.charAt(0).toUpperCase() + str.slice(1)
 }
+
+/**
+ * Check if two values are loosely equal - that is,
+ * if they are plain objects, do they have the same shape?
+ */
+export function looseEqual(a: any, b: any): boolean {
+  if (a === b) return true
+  const isObjectA = isObject(a)
+  const isObjectB = isObject(b)
+  if (isObjectA && isObjectB) {
+    try {
+      const isArrayA = isArray(a)
+      const isArrayB = isArray(b)
+      if (isArrayA && isArrayB) {
+        return (
+          a.length === b.length &&
+          a.every((e: any, i: any) => looseEqual(e, b[i]))
+        )
+      } else if (a instanceof Date && b instanceof Date) {
+        return a.getTime() === b.getTime()
+      } else if (!isArrayA && !isArrayB) {
+        const keysA = Object.keys(a)
+        const keysB = Object.keys(b)
+        return (
+          keysA.length === keysB.length &&
+          keysA.every(key => looseEqual(a[key], b[key]))
+        )
+      } else {
+        /* istanbul ignore next */
+        return false
+      }
+    } catch (e) {
+      /* istanbul ignore next */
+      return false
+    }
+  } else if (!isObjectA && !isObjectB) {
+    return String(a) === String(b)
+  } else {
+    return false
+  }
+}