Function TestEmptyBlockShortCircuit

protocols/cpc/fetcher/fetcher_test.go:606–638

Tests that if a block is empty (i.e. header only), no body request should be made, and instead the header should be assembled into a whole block in itself.

(t *testing.T)

// Tests that if a block is empty (i.e. header only), no body request should be
// made, and instead the header should be assembled into a whole block in itself.
func TestEmptyBlockShortCircuit(t *testing.T) {
	// Create a chain of blocks to import
	hashes, blocks := makeChain(32, 0, genesis)

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

	// Add a monitoring hook for all internal events
	fetching := make(chan []common.Hash)
	tester.fetcher.fetchingHook = func(hashes []common.Hash) { fetching <- hashes }

	completing := make(chan []common.Hash)
	tester.fetcher.completingHook = func(hashes []common.Hash) { completing <- hashes }

	imported := make(chan *types.Block)
	tester.fetcher.importedHook = func(block *types.Block) { imported <- block }

	// Iteratively announce blocks until all are imported
	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)

		// All announces should fetch the header
		verifyFetchingEvent(t, fetching, true)

		// Only blocks with data contents should request bodies
		verifyCompletingEvent(t, completing, len(blocks[hashes[i]].Transactions()) > 0)

		// Irrelevant of the construct, import should succeed
		verifyImportEvent(t, imported, true)
	}
	verifyImportDone(t, imported)
}

// Tests that a peer is unable to use unbounded memory with sending infinite
// block announcements to a node, but that even in the face of such an attack,