feat: add reset function for observer

packages/core/src/internal/observer.ts

@@ -1,18 +1,20 @@
 import { compile } from '../index'
 import { CompileResult, CompileOptions } from '../compiler'
-import { TokenValue } from '../types'
+import { RawToken, TokenValue } from '../types'
 
 export type Watcher = (payload: CompileResult) => void
 type Compile = typeof compile
 
 export class ThemekitObserver {
+  private originalTokens: RawToken[]
   private options: CompileOptions
   private compile: Compile
   private watchers: Set<Watcher> = new Set()
 
   constructor(options: CompileOptions, _compile: Compile = compile) {
     this.compile = _compile
     this.options = options
+    this.originalTokens = options.tokens
     this.run(options)
   }
 
@@ -29,6 +31,11 @@ export class ThemekitObserver {
     this.run(this.options)
   }
 
+  reset() {
+    this.options.tokens = this.originalTokens
+    this.run(this.options)
+  }
+
   private run(options: CompileOptions) {
     setImmediate(() => {
       this.emit(this.compile(options))