# The Merge Test Plan

## Spec documents
* [consensus-specs](https://github.com/ethereum/consensus-specs/tree/dev/specs/merge)
* [EIP-3675](https://eips.ethereum.org/EIPS/eip-3675)
* [EIP-4399](https://eips.ethereum.org/EIPS/eip-4399)
* [Engine API](https://github.com/ethereum/execution-apis/blob/main/src/engine/specification.md)
* Optimistic sync

## Standalone (Unit)

### consensus-specs
* is_merge_transition_complete
* is_merge_transition_block
* is_execution_enabled
* compute_timestamp_at_slot
* get_inactivity_penalty_deltas
* slash_validator
* process_block
* process_execution_payload
* process_slashings
* initialize_beacon_state_from_eth1
* is_valid_terminal_pow_block
* validate_merge_block
* upgrade_to_merge
* get_pow_block_at_terminal_total_difficulty
* get_terminal_pow_block
* prepare_execution_payload
* get_execution_payload

### EIP-3675 + EIP-4399
* Blockchain tests (client will have to switch to the PoS consensus engine to run these tests)
* PoW block processing
* decsendands of a terminal block are not processed
* Block structure
* blocks are discarded if the value of either of the following fields deviates from the corresponding constant: `ommersHash`, `difficulty`, `nonce`, `ommers`
* `mixHash` can be set to a random value
* `extraData` respects `MAX_EXTRA_DATA_BYTES`
* other fields remain unchanged
* Block validity
* `difficulty` isn't verified against difficulty formula
* `nonce` and `mixHash` aren't verified against Ethash rules
* list of ommers and each ommer isn't verified (don't know how to check though as the list must be empty)
* Transition block validity
* a parent of `TRANSITION_BLOCK` satisfies terminal PoW block conditions
* Other block validaty rules remain
* Block and ommer rewards
* `coinbase` account doesn't receive block rewards
* `coinbase` account doesn't receive ommer rewards (seems infeasible to check)
* transaction fees remain
* EVM
* `RANDOM` opcode returns expected value
* Regression
* check that 3675 and 4399 aren't taking effect before the `TRANSITION_BLOCK`
* Fuzzing

## Integration (Hive)

### Engine API

* CL mock + EL
* `eth_` namespace is also exposed
* EL respects the order of `forkchoiceUpdated` calls
* `engine_executePayload`
* `engine_forkchoiceUpdated`
* `engine_getPayload`
* CL + EL mock
* CL respects the order of method calls while assigning JSON-RPC request IDs
* CL + EL
* CL implementation of Engine API methods
* `engine_executePayload`
* `engine_forkchoiceUpdated`
* `engine_getPayload`

### EIP-3675 + EIP-4399

* CL mock + EL
* switches the fork choice rule upon the first `POS_FORKCHOICE_UPDATED` event
* `POS_FORKCHOICE_UPDATED` updates the head
* `POS_FORKCHOICE_UPDATED` updates finalized block
* head isn't changed until `POS_FORKCHOICE_UPDATED` is received, even if the new payload is imported
* descendants of a terminal block are not propagated
* any block is not propagated after the first block gets finalized
* does not sync beyond terminal block
* block with transaction using `RANDOM` opcode is executed as expected starting with `TRANSITION_BLOCK`
* block with transaction using `DIFFICULTY` opcode is executed as expected before the `TRANSITION_BLOCK`
* Transition
* block structure, block validity, block rewards, and fork choice changes takes effect starting with `TRANSITION_BLOCK`
* payload is successfully created upon request *before* the transition, i.e. the transition block
* switch between several transition PoW blocks happens successfully

### consensus-specs + EIPs
* CL + EL
* consensus-specs
* state transition happy case
* state transition invalid payload wrt execution
* fork choice (see the Transition below)
* Transition
* transition scenario with no overrides
* payload is successfully created upon request *before* the transition, i.e. the transition block
* CL passes transition block while syncing optimistically and must go back to verify TTD or TBH
* list all other possible scenarios of the transition process
* case when `TERMINAL_BLOCK_HASH` is set
* `TRANSITION_BLOCK` must be a child of a block identified by `TERMINAL_BLOCK_HASH`
* list all other possible scenarios of the transition process with `TERMINAL_BLOCK_HASH` override
* block structure, block validity, block rewards, and fork choice changes takes effect starting with `TRANSITION_BLOCK`
* PoS chain takes precedence
* `TRANSITION_BLOCK` isn't a child of a terminal PoW block
* in lock-step
* after syncing optimistically
* terminal PoW block is invalid wrt execution ruleset -- `TRANSITION_BLOCK` can't be verified at all
* `TRANSITION_BLOCK` is invalid wrt execution ruleset
* switch between several terminal PoW blocks happens successfully
* switch between several transition blocks happens successfully
* withheld transition PoW block is successfully processed -- network partitioning
* transition block with the payload which parent is unavailable doesn't brick a node and it can proceed with building the chain and attesting, and can successfully complete the transition process

## System (Testnets)
* general purpose
* stress testnets
* production sized

## Useful resources
* Mergemock
* https://github.com/protolambda/mergemock
* Test cases for Merge
* https://hackmd.io/z2h_RAJoTHWSRka-9MDEVg
* Engine API test vectors for The Merge™
* https://notes.ethereum.org/rmVErCfCRPKGqGkUe89-Kg
* EIP 4399 test vectors (Kintsugi)
* https://notes.ethereum.org/dfVXr2h2TqWDKSXZaMwGTw
* Kintzugi testing
* https://github.com/marioevz/kintsugi_testing
* Consensus spec tests
* https://github.com/ethereum/consensus-spec-tests
* Retesteth
* https://github.com/ethereum/retesteth
* EL tests
* https://github.com/ethereum/tests
* Hive
* https://github.com/ethereum/hive
* Eth2 Hive - take 2
* https://github.com/ethereum/hive/pull/481
* Prysmatic end-to-end testing tool
* https://github.com/prysmaticlabs/prysm/tree/develop/testing/endtoend
* EVM-fuzzing
* https://github.com/MariusVanDerWijden/FuzzyVM
* Engine-API fuzzing
* https://github.com/MariusVanDerWijden/merge-fuzz
* Transaction fuzzing
* https://github.com/MariusVanDerWijden/tx-fuzz
* EIP-3675 + EIP-4399 blockchain tests
* https://docs.google.com/spreadsheets/d/1V8egI6VbtZR_sqUNCdX2QeRVb9fCJ3QmzCu8VZFs5pA/edit#gid=0
* FuzzyVM
* https://github.com/MariusVanDerWijden/FuzzyVM