fix: change network request sweep interval from 1s -> 10s (#25209)

* fix: change sweep interval from 1s -> 10s

* binaries

* update variable name

* use DI to make PreRequest class more testable

* revert code [skip ci]

* try tweaking test

Co-authored-by: Matt Henkes <mjhenkes@gmail.com>

packages/proxy/lib/http/util/prerequests.ts

@@ -78,27 +78,33 @@ class StackMap<T> {
 // ever comes in, we don't want to block proxied requests indefinitely.
 export class PreRequests {
   requestTimeout: number
+  sweepInterval: number
   pendingPreRequests = new StackMap<PendingPreRequest>()
   pendingRequests = new StackMap<PendingRequest>()
-  sweepInterval: ReturnType<typeof setInterval>
+  sweepIntervalTimer: NodeJS.Timeout
 
-  constructor (requestTimeout = 500) {
+  constructor (
+    requestTimeout = 500,
+    // 10 seconds
+    sweepInterval = 1000 * 10,
+  ) {
     // If a request comes in and we don't have a matching pre-request after this timeout,
     // we invoke the request callback to tell the server to proceed (we don't want to block
     // user requests indefinitely).
     this.requestTimeout = requestTimeout
+    this.sweepInterval = sweepInterval
 
     // Discarding prerequests on the other hand is not urgent, so we do it on a regular interval
     // rather than with a separate timer for each one.
     // 2 times the requestTimeout is arbitrary, chosen to give plenty of time and
     // make sure we don't discard any pre-requests prematurely but that we don't leak memory over time
     // if a large number of pre-requests don't match up
     // fixes: https://github.com/cypress-io/cypress/issues/17853
-    this.sweepInterval = setInterval(() => {
+    this.sweepIntervalTimer = setInterval(() => {
       const now = Date.now()
 
       this.pendingPreRequests.removeMatching(({ timestamp, browserPreRequest }) => {
-        if (timestamp + this.requestTimeout * 2 < now) {
+        if (timestamp + this.sweepInterval < now) {
           debugVerbose('timed out unmatched pre-request: %o', browserPreRequest)
           metrics.unmatchedPreRequests++
 
@@ -107,7 +113,7 @@ export class PreRequests {
 
         return true
       })
-    }, this.requestTimeout * 2)
+    }, this.sweepInterval)
   }
 
   addPending (browserPreRequest: BrowserPreRequest) {

packages/proxy/test/unit/http/util/prerequests.spec.ts

@@ -62,6 +62,7 @@ describe('http/util/prerequests', () => {
 
   // https://github.com/cypress-io/cypress/issues/17853
   it('eventually discards pre-requests that don\'t match requests', (done) => {
+    preRequests = new PreRequests(10, 200)
     preRequests.addPending({ requestId: '1234', url: 'foo', method: 'GET' } as BrowserPreRequest)
 
     // preRequests garbage collects pre-requests that never matched up with an incoming request after around
@@ -75,6 +76,6 @@ describe('http/util/prerequests', () => {
       }
 
       preRequests.get({ proxiedUrl: 'foo', method: 'GET' } as CypressIncomingRequest, () => {}, cb)
-    }, 50)
+    }, 1200)
   })
 })