feat: bind methods to context (#74)

Co-authored-by: Evan You <yyx990803@gmail.com>

src/app.ts

@@ -1,7 +1,7 @@
 import { reactive } from '@vue/reactivity'
 import { Block } from './block'
 import { Directive } from './directives'
-import { createContext } from './context'
+import { bindContextMethods, createContext } from './context'
 import { toDisplayString } from './directives/text'
 import { nextTick } from './scheduler'
 
@@ -13,6 +13,7 @@ export const createApp = (initialData?: any) => {
   const ctx = createContext()
   if (initialData) {
     ctx.scope = reactive(initialData)
+    bindContextMethods(ctx.scope)
 
     // handle custom delimiters
     if (initialData.$delimiters) {

src/context.ts

@@ -61,8 +61,18 @@ export const createScopedContext = (ctx: Context, data = {}): Context => {
       }
     })
   )
+
+  bindContextMethods(reactiveProxy)
   return {
     ...ctx,
     scope: reactiveProxy
   }
 }
+
+export const bindContextMethods = (scope: Record<string, any>) => {
+  for (const key of Object.keys(scope)) {
+    if (typeof scope[key] === 'function') {
+      scope[key] = scope[key].bind(scope)
+    }
+  }
+}