refactor(javascript): MessageProcessor abstraction added and implemented in catcher event processing pipeline

- MessageProcessor interface and MessageHint type
- BrowserMessageProcessor, BreadcrumbsMessageProcessor, ConsoleCatcherMessageProcessor, DebugMessageProcessor
- replaced inline addon logic with sequential MessageProcessor pipeline

Author: Reversean

packages/core/src/errors.ts

@@ -10,6 +10,6 @@ export type { Transport } from './transports/transport';
 export type { SanitizerTypeHandler } from './modules/sanitizer';
 export { StackParser } from './modules/stack-parser';
 export { buildElementSelector } from './utils/selector';
-export { EventRejectedError } from './errors';
 export { isErrorProcessed, markErrorAsProcessed } from './utils/event';
 export type { BreadcrumbStore, BreadcrumbsAPI, BreadcrumbHint, BreadcrumbInput } from './breadcrumbs/breadcrumb-store';
+export type { MessageProcessor, ProcessingPayload } from './messages/message-processor';

packages/core/src/index.ts

@@ -0,0 +1,43 @@
+import type { CatcherMessagePayload, CatcherMessageType } from '@hawk.so/types';
+
+/**
+ * Extracted addons type from catcher message payload.
+ *
+ * @typeParam T - catcher message type
+ */
+type ExtractAddons<T extends CatcherMessageType> =
+  CatcherMessagePayload<T> extends { addons?: infer A } ? A : never;
+
+/**
+ * Payload type used during message processing pipeline.
+ *
+ * Same as {@link CatcherMessagePayload} but with `addons` always defined and partially filled —
+ * processors may contribute individual addon fields independently of each other.
+ *
+ * @typeParam T - catcher message type this payload belongs to
+ */
+export type ProcessingPayload<T extends CatcherMessageType> =
+  Omit<CatcherMessagePayload<T>, 'addons'> & {
+    addons: Partial<ExtractAddons<T>>;
+  };
+
+/**
+ * Single step in message processing pipeline before message is sent.
+ *
+ * @typeParam T - catcher message type this processor handles
+ */
+export interface MessageProcessor<T extends CatcherMessageType = CatcherMessageType> {
+  /**
+   * Handles input message. May mutate, replace or drop it.
+   *
+   * Dropped message won't be sent.
+   *
+   * @param payload - processed event message payload with partially-built addons
+   * @param error - original error
+   * @returns modified payload, or `null` to drop message
+   */
+  apply(
+    payload: ProcessingPayload<T>,
+    error?: Error | string,
+  ): ProcessingPayload<T> | null
+}

packages/core/src/messages/message-processor.ts

@@ -154,7 +154,6 @@ export class Sanitizer {
     depth: number,
     seen: WeakSet<object>
   ): Record<string, any> | '<deep object>' | '<big object>' {
-
     // If the maximum depth is reached, return a placeholder
     if (depth > Sanitizer.maxDepth) {
       return '<deep object>';

packages/core/src/modules/sanitizer.ts

@@ -1,6 +1,6 @@
 {
   "name": "@hawk.so/javascript",
-  "version": "3.2.20",
+  "version": "3.2.21",
   "description": "JavaScript errors tracking for Hawk.so",
   "files": [
     "dist"