assertions

On-chain assertions backed by the assertions.eth contract: verify view return values and chain state atomically. Requires load assertions.

load assertions

Configuration variables

Config variables are set with set (fully qualified, including the module prefix) and are only readable by their own module and the user script.

Variable	Type	Default	Description
$assertions:address	address	—	Override the resolved assertions contract address (forks / testing).
$assertions:combinators	address	—	Override the resolved combinators contract address (forks / testing).

Commands

Command	Description
assertions:assert	Assert that an on-chain expression satisfies a comparison, on-chain.
assertions:assert-balance	Assert the native balance of an account, on-chain.
assertions:assert-block-number	Assert the current block number, on-chain.
assertions:assert-chainid	Assert the chain ID equals an expected value, on-chain.
assertions:assert-code	Assert an address has deployed code, on-chain.
assertions:assert-codehash	Assert an address has a specific code hash, on-chain.
assertions:assert-no-code	Assert an address has no deployed code, on-chain.
assertions:assert-timestamp	Assert the current block timestamp, on-chain.

Helpers

Helper	Returns	Description
@assertions:absdiff!	number	Absolute difference
@assertions:balance!	number	Read a balance on-chain at assertion time: the native balance for ETH, or an ERC-20 balanceOf for any token symbol or address.
@assertions:blocknumber!	number	The block number at assertion time (not at script build time).
@assertions:bool!	bool	Compose live comparisons with on-chain logic (and, or, xor, not), evaluated at assertion time via the combinators contract.
@assertions:bytelen!	number	The raw byte length of the return data of a call, on-chain (a uint256[] with n items is 64 + n*32 bytes).
@assertions:bytes!	number	Bitwise word operations computed on-chain (& `
@assertions:chainid!	number	The chain id at assertion time, read on-chain — unlike assert-chainid it composes into expressions.
@assertions:charset!	bool	Whether every byte of the string return of a call is in a character class, checked on-chain — only-lowercase is @charset!(call a-z).
@assertions:codehash	bytes32	Read the code hash of an address at script build time, with EXTCODEHASH semantics: bytes32(0) for a nonexistent account (zero nonce, balance and code), keccak256 of the code otherwise. Matches what @codehash! reads on-chain at assertion time.
@assertions:codehash!	bytes32	The EXTCODEHASH of an account, read on-chain at assertion time: bytes32(0) for a nonexistent account, keccak256 of the code otherwise. The account can be a :: call resolving to an address, such as a proxy implementation.
@assertions:hash!	bytes32	keccak256 of the raw return data of a call, computed on-chain — compare structs, arrays or long strings against a precomputed hash.
@assertions:includes!	bool	Whether the string return of a call contains a substring, checked on-chain — exact byte sequence, case-sensitive, no wildcards.
@assertions:invoke!	any	Call a read-only function with live arguments at assertion time: the target and any argument may be a :: call or an on-chain helper, compiled to the combinators invoke primitive.
@assertions:len!	number	The decoded length of the dynamic return value of a call, on-chain: element count for arrays, byte length for string/bytes.
@assertions:max!	number	Maximum of two or more values, computed on-chain at assertion time.
@assertions:min!	number	Minimum of two or more values, computed on-chain at assertion time.
@assertions:not!	any	Negation computed on-chain, dispatched on the operand: logical not for booleans (stays a bool), bitwise complement of the raw 32-byte word for numbers and bytes32. Never a conversion — cast explicitly with @bytes!(x) first if needed.
@assertions:num!	number	Compose live calls and constants with on-chain arithmetic (+ - * / % ^, xor), evaluated at assertion time via the combinators contract.
@assertions:split!	string	Split the string return of a call on a delimiter and select one segment, on-chain. A negative index counts from the end (-1 = last segment).
@assertions:timestamp!	number	The block timestamp at assertion time (not at script build time).