refactor: better comments and remove duplication

Author: logaretm

packages/core/src/index.ts

@@ -517,4 +517,5 @@ export {
   runInRandomSafeContext as _INTERNAL_runInRandomSafeContext,
   safeDateNow as _INTERNAL_safeDateNow,
   safeMathRandom as _INTERNAL_safeMathRandom,
+  type RandomSafeContextRunner as _INTERNAL_RandomSafeContextRunner,
 } from './utils/safeRandomGeneratorRunner';

packages/core/src/utils/ratelimit.ts

@@ -1,6 +1,6 @@
 import type { DataCategory } from '../types-hoist/datacategory';
 import type { TransportMakeRequestResponse } from '../types-hoist/transport';
-import { runInRandomSafeContext, safeDateNow } from './safeRandomGeneratorRunner';
+import { safeDateNow } from './safeRandomGeneratorRunner';
 
 // Intentionally keeping the key broad, as we don't know for sure what rate limit headers get returned from backend
 export type RateLimits = Record<string, number>;
@@ -13,7 +13,7 @@ export const DEFAULT_RETRY_AFTER = 60 * 1000; // 60 seconds
  * @param now current unix timestamp
  *
  */
-export function parseRetryAfterHeader(header: string, now: number = runInRandomSafeContext(() => Date.now())): number {
+export function parseRetryAfterHeader(header: string, now: number = safeDateNow()): number {
   const headerDelay = parseInt(`${header}`, 10);
   if (!isNaN(headerDelay)) {
     return headerDelay * 1000;

packages/core/src/utils/safeRandomGeneratorRunner.ts

@@ -1,8 +1,8 @@
 import { GLOBAL_OBJ } from './worldwide';
 
-type SafeRandomContextRunner = <T>(callback: () => T) => T;
+export type RandomSafeContextRunner = <T>(callback: () => T) => T;
 
-let RESOLVED_RUNNER: SafeRandomContextRunner | undefined;
+let RESOLVED_RUNNER: RandomSafeContextRunner | undefined;
 
 /**
  * Simple wrapper that allows SDKs to *secretly* set context wrapper to generate safe random IDs in cache components contexts
@@ -14,7 +14,7 @@ export function runInRandomSafeContext<T>(cb: () => T): T {
   }
 
   const sym = Symbol.for('__SENTRY_SAFE_RANDOM_ID_WRAPPER__');
-  const globalWithSymbol: typeof GLOBAL_OBJ & { [sym]?: SafeRandomContextRunner } = GLOBAL_OBJ;
+  const globalWithSymbol: typeof GLOBAL_OBJ & { [sym]?: RandomSafeContextRunner } = GLOBAL_OBJ;
   if (!(sym in globalWithSymbol) || typeof globalWithSymbol[sym] !== 'function') {
     return cb();
   }

packages/nextjs/src/server/prepareSafeIdGeneratorContext.ts

@@ -1,8 +1,8 @@
-import { debug, GLOBAL_OBJ } from '@sentry/core';
+import { type _INTERNAL_RandomSafeContextRunner as RandomSafeContextRunner, debug, GLOBAL_OBJ } from '@sentry/core';
 import { DEBUG_BUILD } from '../common/debug-build';
 
-type SafeRandomContextRunner = <T>(callback: () => T) => T;
-
+// Inline AsyncLocalStorage interface from current types
+// Avoids conflict with resolving it from getBuiltinModule
 type OriginalAsyncLocalStorage = typeof AsyncLocalStorage;
 
 /**
@@ -11,7 +11,7 @@ type OriginalAsyncLocalStorage = typeof AsyncLocalStorage;
  */
 export function prepareSafeIdGeneratorContext(): void {
   const sym = Symbol.for('__SENTRY_SAFE_RANDOM_ID_WRAPPER__');
-  const globalWithSymbol: typeof GLOBAL_OBJ & { [sym]?: SafeRandomContextRunner } = GLOBAL_OBJ;
+  const globalWithSymbol: typeof GLOBAL_OBJ & { [sym]?: RandomSafeContextRunner } = GLOBAL_OBJ;
   const als = getAsyncLocalStorage();
   if (!als) {
     DEBUG_BUILD &&
@@ -27,11 +27,14 @@ export function prepareSafeIdGeneratorContext(): void {
 
 function getAsyncLocalStorage(): OriginalAsyncLocalStorage | undefined {
   // May exist in the Next.js runtime globals
-  if ('AsyncLocalStorage' in GLOBAL_OBJ) {
+  // Doesn't exist in some of our tests
+  if (typeof AsyncLocalStorage !== 'undefined') {
     return AsyncLocalStorage;
   }
 
   // Try to resolve it dynamically without synchronously importing the module
+  // This is done to avoid importing the module synchronously at the top
+  // which means this is safe across runtimes
   if ('getBuiltinModule' in process && typeof process.getBuiltinModule === 'function') {
     const { AsyncLocalStorage } = process.getBuiltinModule('async_hooks') ?? {};