👌🎨 Reuse matchList in tracer

packages/core/src/tools/utils.spec.ts

@@ -673,6 +673,11 @@ describe('matchList', () => {
     expect(matchList(list, 'qux')).toBe(false)
   })
 
+  it('should compare strings using startsWith when enabling the option', () => {
+    const list = ['http://my.domain.com']
+    expect(matchList(list, 'http://my.domain.com/action', true)).toBe(true)
+  })
+
   it('should catch error from provided function', () => {
     spyOn(display, 'error')
     const list = [

packages/core/src/tools/utils.ts

@@ -666,20 +666,25 @@ export function isMatchOption(item: unknown): item is MatchOption {
   const itemType = getType(item)
   return itemType === 'string' || itemType === 'function' || item instanceof RegExp
 }
-export function matchList(list: MatchOption[], value: string): boolean {
+/**
+ * Returns true if value can be matched by at least one of the provided MatchOptions.
+ * When comparing strings, setting useStartsWith to true will compare the value with the start of
+ * the option, instead of requiring an exact match.
+ */
+export function matchList(list: MatchOption[], value: string, useStartsWith = false): boolean {
   return list.some((item) => {
-    if (typeof item === 'function') {
-      try {
+    try {
+      if (typeof item === 'function') {
         return item(value)
-      } catch (e) {
-        display.error(e)
-        return false
+      } else if (item instanceof RegExp) {
+        return item.test(value)
+      } else if (typeof item === 'string') {
+        return useStartsWith ? startsWith(value, item) : item === value
       }
+    } catch (e) {
+      display.error(e)
     }
-    if (item instanceof RegExp) {
-      return item.test(value)
-    }
-    return item === value
+    return false
   })
 }
 

packages/rum-core/src/domain/tracing/tracer.ts

@@ -4,11 +4,10 @@ import {
   performDraw,
   isNumber,
   assign,
-  display,
   find,
-  startsWith,
   getType,
   isMatchOption,
+  matchList,
 } from '@datadog/browser-core'
 import type { RumConfiguration } from '../configuration'
 import type {
@@ -110,7 +109,9 @@ function injectHeadersIfTracingAllowed(
     return
   }
 
-  const tracingOption = findTracingOptionForUrl(configuration.allowedTracingUrls, context.url!)
+  const tracingOption = find(configuration.allowedTracingUrls, (tracingOption: TracingOption) =>
+    matchList([tracingOption.match], context.url!, true)
+  )
   if (!tracingOption) {
     return
   }
@@ -121,26 +122,6 @@ function injectHeadersIfTracingAllowed(
   inject(makeTracingHeaders(context.traceId, context.spanId, context.traceSampled, tracingOption.headersTypes))
 }
 
-function findTracingOptionForUrl(configurationTracingUrls: TracingOption[], url: string) {
-  return find(configurationTracingUrls, (config: TracingOption) => {
-    try {
-      const item = config.match
-      if (typeof item === 'function') {
-        return item(url)
-      }
-      if (item instanceof RegExp) {
-        return item.test(url)
-      }
-      if (typeof item === 'string') {
-        return startsWith(url, item)
-      }
-    } catch (e) {
-      display.error(e)
-    }
-    return false
-  })
-}
-
 export function isTracingSupported() {
   return getCrypto() !== undefined
 }