Function newTestScrapeLoop

scrape/helpers_test.go:89–141

newTestScrapeLoop is the initial scrape loop for all tests. It returns scrapeLoop and mock scraper you can customize. It's recommended to use withXYZ functions for simple option customizations, e.g: sl, _ := newTestScrapeLoop(t, withCtx(customCtx)) However, when changing more than one scrapeLoop

(t testing.TB, opts ...func(sl *scrapeLoop))

// newTestScrapeLoop-like constructors. It should be flexible enough with scrapeLoop
// used for initial options.
func newTestScrapeLoop(t testing.TB, opts ...func(sl *scrapeLoop)) (_ *scrapeLoop, scraper *testScraper) {
	metrics := newTestScrapeMetrics(t)
	sl := &scrapeLoop{
		stopped: make(chan struct{}),

		l:     promslog.NewNopLogger(),
		cache: newScrapeCache(metrics),

		interval:            10 * time.Millisecond,
		timeout:             1 * time.Hour,
		sampleMutator:       nopMutator,
		reportSampleMutator: nopMutator,
		buffers:             pool.New(1e3, 1e6, 3, func(sz int) any { return make([]byte, 0, sz) }),
		metrics:             metrics,
		maxSchema:           histogram.ExponentialSchemaMax,
		honorTimestamps:     true,
		enableCompression:   true,
		validationScheme:    model.UTF8Validation,
		symbolTable:         labels.NewSymbolTable(),
		// Tests assume those features are enabled, unless explicitly turned off.
		appendMetadataToWAL: true,
		parseST:             true,
	}
	for _, o := range opts {
		o(sl)
	}

	if sl.appendable != nil && sl.appendableV2 != nil {
		t.Fatal("select the appendable to use, both were passed, likely a bug")
	}

	// Validate user opts for convenience.
	require.Nil(t, sl.parentCtx, "newTestScrapeLoop does not support injecting non-nil parent context")
	require.Nil(t, sl.appenderCtx, "newTestScrapeLoop does not support injecting non-nil appender context")
	require.Nil(t, sl.cancel, "newTestScrapeLoop does not support injecting custom cancel function")
	require.Nil(t, sl.scraper, "newTestScrapeLoop does not support injecting scraper, it's mocked, use the returned scraper")

	rootCtx := t.Context()
	// Use sl.ctx for context injection.
	// True contexts (sl.appenderCtx, sl.parentCtx, sl.ctx) are populated from it
	if sl.ctx != nil {
		rootCtx = sl.ctx
	}
	ctx, cancel := context.WithCancel(rootCtx)
	sl.ctx = ctx
	sl.cancel = cancel
	sl.appenderCtx = rootCtx
	sl.parentCtx = rootCtx

	scraper = &testScraper{}
	sl.scraper = scraper
	return sl, scraper
}

func newTestScrapePool(t *testing.T, app compatAppendable, appV2 bool, injectNewLoop func(options scrapeLoopOptions) loop) *scrapePool {
	sa := selectAppendable(app, appV2)