require.Equal(t,refB1,eq.SafeL2Head(),"L2 reset should go back to sequence window ago: blocks with origin E and D are not safe until we reconcile, C is extra, and B1 is the end we look for")
require.Equal(t,refB,eq.Progress().Origin,"Expecting to be set back derivation L1 progress to B")
require.Equal(t,refA1,eq.Finalized(),"A1 is recognized as finalized before we run any steps")
// we are not adding blocks in this test,
// but we can still trigger post-processing for the already existing safe head,
// so the engine can prepare to finalize that.
// now say C1 was included in D and became the new safe head
eq.progress.Origin=refD
eq.safeHead=refC1
eq.postProcessSafeL2()
// now say D0 was included in E and became the new safe head
eq.progress.Origin=refE
eq.safeHead=refD0
eq.postProcessSafeL2()
// let's finalize C, which included B0, but not B1
eq.Finalize(refC.ID())
// let's finalize D (current L1), from which we fully derived C1 (it was safe head), but not D0 (included in E)
eq.Finalize(refD.ID())
// Now a few steps later, without consuming any additional L1 inputs,
// we should be able to resolve that B0 is now finalized
// we should be able to resolve that B1 is now finalized, since it was included in finalized L1 block C
// Check L2 traversal against L2 Genesis data, to make sure the engine is on the correct chain, instead of attempting sync with different L2 destination.
// Check L1 comparison against L1 Genesis data, to make sure the L1 data is from the correct chain, instead of attempting sync with different L1 source.
// sanity check that the L1 origin block number is coherent
ifparent.L1Origin.Number+1!=n.L1Origin.Number{
returnnil,fmt.Errorf("l2 parent %s of %s has L1 origin %s that is not before %s",parent,n,parent.L1Origin,n.L1Origin)
}
// sanity check that the later sequence number is 0, if it changed between the L2 blocks
ifn.SequenceNumber!=0{
returnnil,fmt.Errorf("l2 block %s has parent %s with different L1 origin %s, but non-zero sequence number %d",n,parent,parent.L1Origin,n.SequenceNumber)
}
// if the L1 origin is known to be canonical, then the parent must be too
