Function TestSequentialAnnouncements

protocols/cpc/fetcher/fetcher_test.go:265–287

Tests that a fetcher accepts block announcements and initiates retrievals for them, successfully importing into the local chain.

(t *testing.T)

// Tests that a fetcher accepts block announcements and initiates retrievals for
// them, successfully importing into the local chain.
func TestSequentialAnnouncements(t *testing.T) {
	// Create a chain of blocks to import
	targetBlocks := 4 * hashLimit
	// hashes is in reverse order
	// hashes[-1] should be the genesis block
	hashes, blocks := makeChain(targetBlocks, 0, genesis)

	tester := newTester()
	headerFetcher := tester.makeHeaderFetcher("valid", blocks, -gatherSlack)
	bodyFetcher := tester.makeBodyFetcher("valid", blocks, 0)

	// Iteratively announce blocks until all are imported
	imported := make(chan *types.Block)
	// the hook is run by insert
	tester.fetcher.importedHook = func(block *types.Block) { imported <- block }

	// go from block 1 to the last block
	for i := len(hashes) - 2; i >= 0; i-- {
		tester.fetcher.Notify("valid", hashes[i], uint64(len(hashes)-i-1), time.Now().Add(-arriveTimeout), headerFetcher, bodyFetcher)
		verifyImportEvent(t, imported, true)
	}
	verifyImportDone(t, imported)
}

// Tests that if blocks are announced by multiple peers (or even the same buggy
// peer), they will only get downloaded at most once.