eth2.0-specs/tests/formats/fork_choice

Fork choice tests

The aim of the tests for the fork choice rules.

Test case format

meta.yaml

description: string    -- Optional. Description of test case, purely for debugging purposes.
bls_setting: int       -- see general test-format spec.

anchor_state.ssz_snappy

An SSZ-snappy encoded BeaconState, the state to initialize store with get_forkchoice_store(anchor_state: BeaconState, anchor_block: BeaconBlock) helper.

anchor_block.ssz_snappy

An SSZ-snappy encoded BeaconBlock, the block to initialize store with get_forkchoice_store(anchor_state: BeaconState, anchor_block: BeaconBlock) helper.

steps.yaml

The steps to execute in sequence. There may be multiple items of the following types:

on_tick execution step

The parameter that is required for executing on_tick(store, time).

{ tick: int }   --  to execute `on_tick(store, time)`

After this step, the store object may have been updated.

on_attestation execution step

The parameter that is required for executing on_attestation(store, attestation).

{ attestation: string }:  -- the name of the `attestation_<32-byte-root>.ssz_snappy` file. To execute `on_attestation(store, attestation)` with the given attestation.

The file is located in the same folder (see below).

After this step, the store object may have been updated.

on_block execution step

The parameter that is required for executing on_block(store, block).

{ block: string }:        -- the name of the `block_<32-byte-root>.ssz_snappy` file. To execute `on_block(store, block)` with the given attestation.

The file is located in the same folder (see below).

After this step, the store object may have been updated.

Checks step

The checks to verify the current status of store .

checks: {<store_field_name>: value}   -- the assertions.

<store_field_name> is the field member of Store object that maintained by client implementation. Currently, the possible fields included:

time: int                                   -- store.time
genesis_time: int                           -- store.genesis_time
justified_checkpoint_root: string           -- store.justified_checkpoint.root
finalized_checkpoint_root: string           -- store.finalized_checkpoint_root.root
best_justified_checkpoint_root: string      -- store.best_justified_checkpoint_root.root

For example:

- checks: {
    justified_checkpoint_root: '0x347468b606d03f8429afd491f94e32cd3a2295c2536e808c863a9d132a521dc4',
    head: '0x17aa608f5fce87592c6f02ca6ca3c49ca70b5cef5456697709b2e5894e3879c2'
}

attestation_<32-byte-root>.ssz_snappy

<32-byte-root> is the hash tree root of the given attestation.

Each file is an SSZ-snappy encoded Attestation.

block_<32-byte-root>.ssz_snappy

<32-byte-root> is the hash tree root of the given block.

Each file is an SSZ-snappy encoded SignedBeaconBlock.

Condition

1. Deserialize anchor_state.ssz_snappy and anchor_block.ssz_snappy to initialize the local store object by with get_forkchoice_store(anchor_state, anchor_block) helper.
2. Iterate sequentially through steps.yaml
   • For each execution, look up the corresponding ssz_snappy file. Execute the corresponding helper function on the current store.
   • For each checks step, the assertions on the current store must be satisfied.