Don't truncate the page state start time

DataDog · May 12, 2023 · b3cc4d6 · b3cc4d6
1 parent bfdfcb3
commit b3cc4d6
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Showing 2 changed files with 13 additions and 7 deletions.
diff --git a/packages/rum-core/src/domain/contexts/pageStateHistory.spec.ts b/packages/rum-core/src/domain/contexts/pageStateHistory.spec.ts
@@ -40,10 +40,18 @@ describe('pageStateHistory', () => {
     clock.tick(10)
     pageStateHistory.addPageState(PageState.TERMINATED)
 
-    expect(pageStateHistory.findAll(15 as RelativeTime, 20 as RelativeTime)).toEqual([
+    /*
+    page state time    0     10    20    30    40
+    event time                  15<-------->35
+    */
+    const event = {
+      startTime: 15 as RelativeTime,
+      duration: 20 as RelativeTime,
+    }
+    expect(pageStateHistory.findAll(event.startTime, event.duration)).toEqual([
       {
         state: PageState.PASSIVE,
-        start: 0 as ServerDuration,
+        start: -5000000 as ServerDuration,
       },
       {
         state: PageState.HIDDEN,

diff --git a/packages/rum-core/src/domain/contexts/pageStateHistory.ts b/packages/rum-core/src/domain/contexts/pageStateHistory.ts
@@ -85,14 +85,12 @@ export function startPageStateHistory(
 
       for (let index = pageStateEntries.length - 1; index >= limit; index--) {
         const pageState = pageStateEntries[index]
-        // correct the start time to allays be higher or equal to the event start time
-        const correctedStartTime = eventStartTime > pageState.startTime ? eventStartTime : pageState.startTime
-        // recenter the start time to be relative to the event start time (ex: to be relative to the view start time)
-        const recenteredStartTime = elapsed(eventStartTime, correctedStartTime)
+        // compute the start time relative to the event start time (ex: to be relative to the view start time)
+        const relativeStartTime = elapsed(eventStartTime, pageState.startTime)
 
         pageStateServerEntries.push({
           state: pageState.state,
-          start: toServerDuration(recenteredStartTime),
+          start: toServerDuration(relativeStartTime),
         })
       }