add hw2

node_modules/chromium-bidi/lib/esm/utils/EventEmitter.js

@@ -0,0 +1,67 @@
+/**
+ * Copyright 2022 Google LLC.
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import mitt from 'mitt';
+export class EventEmitter {
+    #emitter = mitt();
+    on(type, handler) {
+        this.#emitter.on(type, handler);
+        return this;
+    }
+    /**
+     * Like `on` but the listener will only be fired once and then it will be removed.
+     * @param event The event you'd like to listen to
+     * @param handler The handler function to run when the event occurs
+     * @return `this` to enable chaining method calls.
+     */
+    once(event, handler) {
+        const onceHandler = (eventData) => {
+            handler(eventData);
+            this.off(event, onceHandler);
+        };
+        return this.on(event, onceHandler);
+    }
+    off(type, handler) {
+        this.#emitter.off(type, handler);
+        return this;
+    }
+    /**
+     * Emits an event and call any associated listeners.
+     *
+     * @param event The event to emit.
+     * @param eventData Any data to emit with the event.
+     * @return `true` if there are any listeners, `false` otherwise.
+     */
+    emit(event, eventData) {
+        this.#emitter.emit(event, eventData);
+    }
+    /**
+     * Removes all listeners. If given an event argument, it will remove only
+     * listeners for that event.
+     * @param event - the event to remove listeners for.
+     * @returns `this` to enable you to chain method calls.
+     */
+    removeAllListeners(event) {
+        if (event) {
+            this.#emitter.all.delete(event);
+        }
+        else {
+            this.#emitter.all.clear();
+        }
+        return this;
+    }
+}
+//# sourceMappingURL=EventEmitter.js.map