General State Tests

The state tests aim is to test the basic workings of the state in isolation.

Location	/GeneralStateTests
Supported Hardforks	Byzantium | Constantinople | EIP150 | EIP158 | Frontier | Homestead
Status	Actively supported

A state test is based around the notion of executing a single transaction, described by the transaction portion of the test. The overarching environment in which it is executed is described by the env portion of the test and includes attributes of the current and previous blocks. A set of pre-existing accounts are detailed in the pre portion and form the world state prior to execution. Similarly, a set of accounts are detailed in the post portion to specify the end world state. Since the data of the blockchain is not given, the opcode BLOCKHASH could not return the hashes of the corresponding blocks. Therefore we define the hash of block number n to be SHA256("n").

The log entries (logs) as well as any output returned from the code (output) is also detailed.

Test Implementation

It is generally expected that the test implementer will read env, transaction and pre then check their results against logs, out, and post.

Note

The structure of state tests was reworked lately, see the associated discussion here.

Test Structure

{
  "testname" : {
    "env" : {
      "currentCoinbase" : "address",
      "currentDifficulty" : "0x020000", //minimum difficulty for mining on blockchain
      "currentGasLimit" : "u64",  //not larger then maxGasLimit = 0x7fffffffffffffff
      "currentNumber" : "0x01",   //Irrelevant to hardfork parameters!
      "currentTimestamp" : "1000", //for blockchain version
      "previousHash" : "h256"
    },
    "post" : {
      "EIP150" : [
        {
          "hash" : "3e6dacc1575c6a8c76422255eca03529bbf4c0dda75dfc110b22d6dc4152396f",
          "indexes" : { "data" : 0, "gas" : 0,  "value" : 0 }
        },
        {
          "hash" : "99a450d8ce5b987a71346d8a0a1203711f770745c7ef326912e46761f14cd764",
          "indexes" : { "data" : 0, "gas" : 0,  "value" : 1 }
        },
        ...
      ],
      "EIP158" : [
        {
          "hash" : "3e6dacc1575c6a8c76422255eca03529bbf4c0dda75dfc110b22d6dc4152396f",
          "indexes" : { "data" : 0,   "gas" : 0,  "value" : 0 }
        },
        {
          "hash" : "99a450d8ce5b987a71346d8a0a1203711f770745c7ef326912e46761f14cd764",
          "indexes" : { "data" : 0,   "gas" : 0,  "value" : 1  }
        },
        ...
      ],
      "Frontier" : [
        ...
      ],
      "Homestead" : [
        ...
      ]
    },
    "pre" : {
        //same as for StateTests
    },
    "transaction" : {
      "data" : [ "" ],
      "gasLimit" : [ "285000",   "100000",  "6000" ],
      "gasPrice" : "0x01",
      "nonce" : "0x00",
      "secretKey" : "45a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8",
      "to" : "095e7baea6a6c7c4c2dfeb977efac326af552d87",
        "value" : [   "10",   "0" ]
      }
  }
}

The env Section

currentCoinbase

The current block’s coinbase address, to be returned by the COINBASE instruction.

currentDifficulty

The current block’s difficulty, to be returned by the DIFFICULTY instruction.

currentGasLimit

The current block’s gas limit.

currentNumber

The current block’s number. Also indicates network rules for the transaction. Since blocknumber = 1000000 Homestead rules are applied to transaction. (see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-2.mediawiki)

currentTimestamp

The current block’s timestamp.

previousHash

The previous block’s hash.

The transaction Section

data

The input data passed to the execution, as used by the CALLDATA… instructions. Given as an array of byte values. See $DATA_ARRAY.

gasLimit

The total amount of gas available for the execution, as would be returned by the GAS instruction were it be executed first.

gasPrice

The price of gas for the transaction, as used by the GASPRICE instruction.

nonce

Scalar value equal to the number of transactions sent by the sender.

address

The address of the account under which the code is executing, to be returned by the ADDRESS instruction.

secretKey

The secret key as can be derived by the v,r,s values if the transaction.

to

The address of the transaction’s recipient, to be returned by the ORIGIN instruction.

value

The value of the transaction (or the endowment of the create), to be returned by the CALLVALUE` instruction (if executed first, before any CALL).

The post Section

Indexes section describes which values from given array to set for transaction before it’s execution on a pre state. Transaction now has data, value, and gasLimit as arrays. post section now has array of implemented forks. For each fork it has another array of execution results on that fork rules with post state root hash and transaction parameters.

The pre Section

The pre section have the format of a mapping between addresses and accounts. Each account has the format:

balance

The balance of the account.

nonce

The nonce of the account.

code

The body code of the account, given as an array of byte values. See $DATA_ARRAY.

storage

The account’s storage, given as a mapping of keys to values. For key used notion of string as digital or hex number e.g: "1200" or "0x04B0" For values used $DATA_ARRAY.