change observed mutations into serializable records

src/record/index.ts

@@ -0,0 +1,70 @@
+import { snapshot } from 'rrweb-snapshot';
+import initObservers from './observer';
+import { mirror } from '../utils';
+import {
+  EventType,
+  event,
+  eventWithTime,
+  recordOptions,
+  IncrementalSource,
+} from '../types';
+
+function on(
+  type: string,
+  fn: EventListenerOrEventListenerObject,
+  target = document,
+) {
+  target.addEventListener(type, fn, { capture: true, passive: true });
+}
+
+function wrapEvent(e: event): eventWithTime {
+  return {
+    ...e,
+    timestamp: Date.now(),
+  };
+}
+
+function record(options: recordOptions) {
+  try {
+    const { emit } = options;
+    // runtime checks for user options
+    if (!emit) {
+      throw new Error('emit function is required');
+    }
+    on('DOMContentLoaded', () => {
+      emit(
+        wrapEvent({
+          type: EventType.DomContentLoaded,
+          data: {
+            href: window.location.href,
+          },
+        }),
+      );
+    });
+    on('load', () => {
+      emit(wrapEvent({ type: EventType.Load, data: {} }));
+      const [node, idNodeMap] = snapshot(document);
+      if (!node) {
+        return console.warn('Failed to snapshot the document');
+      }
+      mirror.map = idNodeMap;
+      emit(wrapEvent({ type: EventType.FullSnapshot, data: { node } }));
+      initObservers({
+        mutationCb: m =>
+          emit(
+            wrapEvent({
+              type: EventType.IncrementalSnapshot,
+              data: {
+                source: IncrementalSource.Mutation,
+                ...m,
+              },
+            }),
+          ),
+      });
+    });
+  } catch (error) {
+    // TODO: handle internal error
+  }
+}
+
+export default record;