prefix tracestate header with sentry=, create regex

Author: lobsterkatie

packages/tracing/src/span.ts

@@ -260,7 +260,7 @@ export class Span implements SpanInterface {
     let headers;
     const traceparent = this.toTraceparent();
     // tracestates live on the transaction, so if this is a free-floating span, there won't be one
-    const tracestate = this.transaction?.tracestate;
+    const tracestate = this.transaction && `sentry=${this.transaction.tracestate}`;
 
     if (format === 'array') {
       // headers = [['sentry-trace', traceparent], ...(tracestate && [['tracestate', tracestate]])];

packages/tracing/test/browser/request.test.ts

@@ -13,6 +13,14 @@ import {
 import { addExtensionMethods } from '../../src/hubextensions';
 import * as tracingUtils from '../../src/utils';
 
+// This is a normal base64 regex, modified to reflect that fact that we strip the trailing = or == off
+const BASE64_MISSING_EQUALS = '([a-zA-Z0-9+/]{4})*(|[a-zA-Z0-9+/]{2,3})';
+
+const TRACESTATE_HEADER_REGEX = new RegExp(
+  `sentry=(${BASE64_MISSING_EQUALS})` +  // our part of the header - should be the only part or at least the first part
+    `(,\\w+=\\w+)*`, // any number of copies of a comma followed by `name=value`
+);
+
 beforeAll(() => {
   addExtensionMethods();
   // @ts-ignore need to override global Request because it's not in the jest environment (even with an
@@ -235,7 +243,7 @@ describe('callbacks', () => {
         'sentry-trace',
         expect.stringMatching(tracingUtils.TRACEPARENT_REGEXP),
       );
-      expect(setRequestHeader).toHaveBeenCalledWith('tracestate', expect.any(String));
+      expect(setRequestHeader).toHaveBeenCalledWith('tracestate', expect.stringMatching(TRACESTATE_HEADER_REGEX));
     });
 
     it('creates and finishes XHR span on active transaction', () => {

packages/tracing/test/span.test.ts

@@ -118,7 +118,7 @@ describe('Span', () => {
       const headers = span.getTraceHeaders('object') as TraceHeadersObj;
 
       expect(headers['sentry-trace']).toEqual(span.toTraceparent());
-      expect(headers.tracestate).toEqual(transaction.tracestate);
+      expect(headers.tracestate).toEqual(`sentry=${transaction.tracestate}`);
     });
 
     it('returns the same data either as an object or an array', () => {

packages/utils/src/string.ts

@@ -2,10 +2,6 @@ import { getGlobalObject } from './compat';
 import { SentryError } from './error';
 import { isRegExp, isString } from './is';
 
-// credit to https://rgxdb.com/; see https://tools.ietf.org/html/rfc4648#section-4 for base64 spec
-// eslint-disable-next-line no-useless-escape
-export const BASE64_REGEX = /^(?:[a-zA-Z0-9+\/]{4})*(?:|(?:[a-zA-Z0-9+\/]{3}=)|(?:[a-zA-Z0-9+\/]{2}==)|(?:[a-zA-Z0-9+\/]{1}===))$/;
-
 /**
  * Truncates given string to the maximum characters count
  *

packages/utils/test/string.test.ts

@@ -1,4 +1,8 @@
-import { BASE64_REGEX, base64ToUnicode, isMatchingPattern, truncate, unicodeToBase64 } from '../src/string';
+import { base64ToUnicode, isMatchingPattern, truncate, unicodeToBase64 } from '../src/string';
+
+// See https://tools.ietf.org/html/rfc4648#section-4 for base64 spec
+// eslint-disable-next-line no-useless-escape
+const BASE64_REGEX = /([a-zA-Z0-9+/]{4})*(|([a-zA-Z0-9+/]{3}=)|([a-zA-Z0-9+/]{2}==))/;
 
 describe('truncate()', () => {
   test('it works as expected', () => {