Prevent errors in Express 5.x applications (#4872)

wantsui · wconti27 · web-flow · commit b81d9d84bfcf · 2024-11-12T12:09:45.000-05:00
* Fix integration by preventing unsafe access to properties.

---------

Co-authored-by: William Conti &lt;william.conti@datadoghq.com&gt;
Co-authored-by: William Conti &lt;58711692+wconti27@users.noreply.github.com&gt;
diff --git a/packages/datadog-instrumentations/src/router.js b/packages/datadog-instrumentations/src/router.js
@@ -112,7 +112,6 @@ function createWrapRouterMethod (name) {
       path: pattern instanceof RegExp ? `(${pattern})` : pattern,
       test: layer => {
         const matchers = layerMatchers.get(layer)
-
         return !isFastStar(layer, matchers) &&
           !isFastSlash(layer, matchers) &&
           cachedPathToRegExp(pattern).test(layer.path)
@@ -121,15 +120,15 @@ function createWrapRouterMethod (name) {
   }
 
   function isFastStar (layer, matchers) {
-    if (layer.regexp.fast_star !== undefined) {
+    if (layer.regexp?.fast_star !== undefined) {
       return layer.regexp.fast_star
     }
 
     return matchers.some(matcher => matcher.path === '*')
   }
 
   function isFastSlash (layer, matchers) {
-    if (layer.regexp.fast_slash !== undefined) {
+    if (layer.regexp?.fast_slash !== undefined) {
       return layer.regexp.fast_slash
     }
 

Original file line number	Diff line number	Diff line change
`@@ -112,7 +112,6 @@ function createWrapRouterMethod (name) {`
`112`	`112`	path: pattern instanceof RegExp ? `(${pattern})` : pattern,
`113`	`113`	`test: layer => {`
`114`	`114`	`const matchers = layerMatchers.get(layer)`
`115`		`-`
`116`	`115`	`return !isFastStar(layer, matchers) &&`
`117`	`116`	`!isFastSlash(layer, matchers) &&`
`118`	`117`	`cachedPathToRegExp(pattern).test(layer.path)`
`@@ -121,15 +120,15 @@ function createWrapRouterMethod (name) {`
`121`	`120`	`}`
`122`	`121`
`123`	`122`	`function isFastStar (layer, matchers) {`
`124`		`- if (layer.regexp.fast_star !== undefined) {`
	`123`	`+ if (layer.regexp?.fast_star !== undefined) {`
`125`	`124`	`return layer.regexp.fast_star`
`126`	`125`	`}`
`127`	`126`
`128`	`127`	`return matchers.some(matcher => matcher.path === '*')`
`129`	`128`	`}`
`130`	`129`
`131`	`130`	`function isFastSlash (layer, matchers) {`
`132`		`- if (layer.regexp.fast_slash !== undefined) {`
	`131`	`+ if (layer.regexp?.fast_slash !== undefined) {`
`133`	`132`	`return layer.regexp.fast_slash`
`134`	`133`	`}`
`135`	`134`