Fix large stack test for elided frames in 1.20

internal/stack/stacks_test.go

@@ -135,6 +135,16 @@ func TestCurrentCreatedBy(t *testing.T) {
 		"TestCurrentCreatedBy.func1 is not in stack:\n%s", stack.Full())
 }
 
+//go:noinline // disable inlining for stack frame ellision in 1.20
+func recurse(n int, endFn func()) {
+	if n <= 0 {
+		endFn()
+		return
+	}
+
+	recurse(n-1, endFn)
+}
+
 func TestAllLargeStack(t *testing.T) {
 	const (
 		stackDepth    = 101
@@ -145,17 +155,11 @@ func TestAllLargeStack(t *testing.T) {
 
 	done := make(chan struct{})
 	for i := 0; i < numGoroutines; i++ {
-		var f func(int)
-		f = func(count int) {
-			if count == 0 {
-				started.Done()
-				<-done
-				return
-			}
-			f(count - 1)
-		}
 		started.Add(1)
-		go f(stackDepth)
+		go recurse(stackDepth, func() {
+			started.Done()
+			<-done
+		})
 	}
 
 	started.Wait()
@@ -168,7 +172,7 @@ func TestAllLargeStack(t *testing.T) {
 	// We want to check this here, so that if the format of the "elided frames" message changes, we catch it.
 	// At the time of writing this test, with a stack depth of 101, we get 2 elided frames:
 	// "...2 frames elided...".
-	assert.Contains(t, string(buf), "frames elided...")
+	assert.Contains(t, string(buf), "frames elided...", "stack doesn't contain elided frames")
 	stacks, err := newStackParser(bytes.NewReader(buf)).Parse()
 	require.NoError(t, err)
 	assert.Greater(t, len(stacks), numGoroutines, "expect more parsed stacks than goroutines")