# State Tests¶

Found in /StateTest, the state tests aim is to test the basic workings of the state in isolation.

It 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.

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

## Basic structure¶

{
"test name 1": {
"env": { ... },
"logs": { ... },
"out": { ... },
"post": { ... },
"pre": { ... },
"transaction": { ... },
},
"test name 2": {
"env": { ... },
"logs": { ... },
"out": { ... },
"post": { ... },
"pre": { ... },
"transaction": { ... },
},
...
}


## Sections¶

• 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 $DATA_ARRAY. gasLimit The total amount of gas available for the execution, as would be returned by the GAS instruction were it be executed first. gasPrice The price of gas for the transaction, as used by the GASPRICE instruction. nonce Scalar value equal to the number of transactions sent by the sender. address The address of the account under which the code is executing, to be returned by the ADDRESS instruction. secretKey The secret key as can be derived by the v,r,s values if the transaction. to The address of the transaction’s recipient, to be returned by the ORIGIN instruction. value The value of the transaction (or the endowment of the create), to be returned by the CALLVALUE instruction (if executed first, before any CALL). • The pre and post sections each have the same format of a mapping between addresses and accounts. Each account has the format: balance The balance of the account. nonce The nonce of the account. code The body code of the account, given as an array of byte values. See$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 $DATA_ARRAY. The logs sections is a mapping between the blooms and their corresponding logentries. Each logentry has the format: address The address of the logentry. data The data of the logentry. topics The topics of the logentry, given as an array of values. Finally, there is one simple key output output The data, given as an array of bytes, returned from the execution (using the RETURN instruction). See$DATA_ARRAY. In order to avoid big data files, there is one exception. If the output data is prefixed with #, the following number represents the size of the output, and not the output directly.

\$DATA_ARRAY - type that intended to contain raw byte data

and for convenient of the users is populated with three types of numbers, all of them should be converted and concatenated to a byte array for VM execution.

The types are:

1. number - (unsigned 64bit)
2. “longnumber” - (any long number)
3. “0xhex_num” - (hex format number)
e.g: [1, 2, 10000, "0xabc345dFF", "199999999999999999999999999999999999999"]`