Document Sn Foundry test utils (#1085)

* Minor structure and code improvements

* fix: openzeppelin_utils snforge dependency

* feat: update CHANGELOG

* fix: linter issues

* Update the documentation

* Add and improve the in-code documentation

* Run linter

* Support changes

* Move test utils doc to a separate page

* Fix success values in mocks

* Update packages/token/src/tests/erc20/test_erc20.cairo

Co-authored-by: Andrew Fleming <[email protected]>

* Update packages/token/src/tests/erc721/test_erc721.cairo

Co-authored-by: Andrew Fleming <[email protected]>

* Update packages/access/src/tests/test_ownable_twostep.cairo

Co-authored-by: Andrew Fleming <[email protected]>

* Update packages/account/src/tests/test_account.cairo

Co-authored-by: Andrew Fleming <[email protected]>

* Update packages/account/src/tests/test_signature.cairo

Co-authored-by: Andrew Fleming <[email protected]>

* Update packages/token/src/tests/erc1155/test_dual1155.cairo

Co-authored-by: Andrew Fleming <[email protected]>

* Update packages/token/src/tests/erc1155/test_erc1155.cairo

Co-authored-by: Andrew Fleming <[email protected]>

* feat: apply review updates

* refactor: format files

* fix: tests

* Update test utils module name in doc

* Fix review issues

* Improve structure of testing doc page

* Minor doc fixes

* Add hint on how to add openzeppelin_testing dependency

* Change references to SnFoundry to snforge

* Change variable names in the example to more generic ones

* Change back openzeppelin::utils module name in doc

* Change module reference in doc from testutils to testing

---------

Co-authored-by: Eric Nordelo <[email protected]>
Co-authored-by: Andrew Fleming <[email protected]>

docs/modules/ROOT/nav.adoc

@@ -43,6 +43,7 @@
 *** xref:/api/upgrades.adoc[API Reference]
 
 ** xref:/api/utilities.adoc[Utilities]
+** xref:/api/testing.adoc[Test Utilities]
 
 * xref:backwards-compatibility.adoc[Backwards Compatibility]
 * xref:contracts::index.adoc[Contracts for Solidity]

docs/modules/ROOT/pages/api/testing.adoc

@@ -0,0 +1,298 @@
+= Testing
+
+:stark: https://docs.starknet.io/architecture-and-concepts/cryptography/stark-curve/[Stark]
+:secp256k1: https://github.com/starkware-libs/cairo/blob/main/corelib/src/starknet/secp256k1.cairo[Secp256k1]
+
+This module provides various helper functions for declaring, deploying,
+and testing Smart Contracts using `snforge` toolchain from Starknet Foundry.
+
+```cairo
+use openzeppelin_testing;
+```
+
+The module isn't part of the `openzeppelin` package and to be accessible has to
+be added as a separate dependency in `Scarb.toml`:
+
+```
+[dev-dependencies]
+openzeppelin_testing = { git = "https://github.com/OpenZeppelin/cairo-contracts.git", tag = "v0.15.0-rc.0" }
+```
+
+== Test Utilities
+
+[.contract]
+[[testing-common]]
+=== `++common++`
+
+A module providing common test helpers.
+
+```cairo
+use openzeppelin_testing::common;
+```
+
+[.contract-index]
+.Members
+--
+.Functions
+* xref:#testing-common-panic_data_to_byte_array[`++panic_data_to_byte_array(panic_data)++`]
+* xref:#testing-common-to_base_16_string[`++to_base_16_string(value)++`]
+* xref:#testing-common-assert_entrypoint_not_found_error[`++assert_entrypoint_not_found_error(result, selector, contract_address)++`]
+
+.Traits
+* xref:#testing-common-IntoBase16StringTrait[`++IntoBase16StringTrait++`]
+--
+
+[#testing-common-Functions]
+==== Functions
+
+[.contract-item]
+[[testing-common-panic_data_to_byte_array]]
+===== `[.contract-item-name]#++panic_data_to_byte_array++#++(panic_data: Array<felt252>) → ByteArray++` [.item-kind]#function#
+
+Converts panic data into a string (`ByteArray`).
+
+`panic_data` is expected to be a valid serialized `ByteArray` with an extra `felt252` at the beginning, which is the BYTE_ARRAY_MAGIC.
+
+[.contract-item]
+[[testing-common-to_base_16_string]]
+===== `[.contract-item-name]#++to_base_16_string++#++(value: felt252) → ByteArray++` [.item-kind]#function#
+
+Converts a `felt252` to a `base16` string padded to 66 characters (including the `0x` prefix).
+
+[.contract-item]
+[[testing-common-assert_entrypoint_not_found_error]]
+==== `[.contract-item-name]#++assert_entrypoint_not_found_error++#<T, +Drop<T>>(result: SyscallResult<T>, selector: felt252, contract_address: ContractAddress)` [.item-kind]#function#
+
+Asserts that the syscall result of a call failed with an "Entrypoint not found" error,
+following the Starknet Foundry emitted error format.
+
+[#testing-common-Traits]
+==== Traits
+
+[.contract-item]
+[[testing-common-IntoBase16StringTrait]]
+==== `[.contract-item-name]#++IntoBase16StringTrait++#` [.item-kind]#trait#
+
+A helper trait that enables a value to be represented as a `base16` string padded to 66 characters
+(including the `0x` prefix). The type of the value must implement `Into<T, felt252>` to be
+convertible to `felt252`.
+
+Usage example:
+
+```cairo
+use openzeppelin_testing::common::IntoBase16String;
+
+let expected_panic_message = format!(
+    "Entry point selector {} not found in contract {}",
+    selector.into_base_16_string(),
+    contract_address.into_base_16_string()
+);
+```
+
+[.contract]
+[[testing-deployment]]
+=== `++deployment++`
+
+```cairo
+use openzeppelin_testing::deployment;
+```
+
+A module containing utilities that simplify declaring and deploying contracts using the `snforge` toolchain.
+
+[.contract-index]
+.Members
+--
+.Functions
+* xref:#testing-deployment-declare_class[`++declare_class(contract_name)++`]
+* xref:#testing-deployment-deploy[`++deploy(contract_class, calldata)++`]
+* xref:#testing-deployment-deploy_at[`++deploy_at(contract_class, contract_address, calldata)++`]
+* xref:#testing-deployment-deploy_another_at[`++deploy_another_at(existing, target_address, calldata)++`]
+* xref:#testing-deployment-declare_and_deploy[`++declare_and_deploy(contract_name, calldata)++`]
+* xref:#testing-deployment-declare_and_deploy_at[`++declare_and_deploy_at(contract_name, target_address, calldata)++`]
+--
+
+[#testing-deployment-Functions]
+==== Functions
+
+[.contract-item]
+[[testing-deployment-declare_class]]
+==== `[.contract-item-name]#++declare_class++#++(contract_name: ByteArray) → ContractClass++` [.item-kind]#function#
+
+Declares a contract with a `snforge` `declare` call and unwraps the result.
+
+[.contract-item]
+[[testing-deployment-deploy]]
+==== `[.contract-item-name]#++deploy++#++(contract_class: ContractClass, calldata: Array<felt252>) → ContractAddress++` [.item-kind]#function#
+
+Deploys an instance of a contract and unwraps the result.
+
+[.contract-item]
+[[testing-deployment-deploy_at]]
+==== `[.contract-item-name]#++deploy_at++#++(contract_class: ContractClass, target_address: ContractAddress, calldata: Array<felt252>)++` [.item-kind]#function#
+
+Deploys an instance of a contract at a given address.
+
+[.contract-item]
+[[testing-deployment-deploy_another_at]]
+==== `[.contract-item-name]#++deploy_another_at++#++(existing: ContractAddress, target_address: ContractAddress, calldata: Array<felt252>)++` [.item-kind]#function#
+
+Deploys a contract using the class hash from another already-deployed contract.
+
+Note that currently, `snforge` does not support redeclaring a contract class. Consequently,
+there is no direct method to deploy a second instance of a contract if neither its `ContractClass`
+nor its `class_hash` is available in the context. This helper function provides a solution by retrieving
+the class hash from an existing contract and using it to facilitate the deployment.
+
+```cairo
+use openzeppelin_testing::deploy_another_at;
+
+let alice_address = setup_account(array!['ALICE_PUBKEY']);
+let bob_address = contract_address_const::<'BOB'>();
+deploy_another_at(alice_address, bob_address, array!['BOB_PUBKEY']);
+```
+
+[.contract-item]
+[[testing-deployment-declare_and_deploy]]
+==== `[.contract-item-name]#++declare_and_deploy++#++(contract_name: ByteArray, calldata: Array<felt252>) → ContractAddress++` [.item-kind]#function#
+
+Combines the declaration of a class and the deployment of a contract into one function call.
+
+[.contract-item]
+[[testing-deployment-declare_and_deploy_at]]
+==== `[.contract-item-name]#++declare_and_deploy_at++#++(contract_name: ByteArray, target_address: ContractAddress, calldata: Array<felt252>)++` [.item-kind]#function#
+
+Combines the declaration of a class and the deployment of a contract at the given address into one function call.
+
+[.contract]
+[[testing-events]]
+=== `++events++`
+
+```cairo
+use openzeppelin_testing::events;
+use openzeppelin_testing::events::EventSpyExt;
+```
+
+A module offering an extended set of functions for handling emitted events, enhancing the default
+event utilities provided by `snforge`. These functions are accessible via the `EventSpyExt`
+trait implemented on the `EventSpy` struct.
+
+[.contract-index]
+.Members
+--
+.Functions
+* xref:#testing-events-assert_only_event[`++assert_only_event(self, from_address, event)++`]
+* xref:#testing-events-assert_emitted_single[`++assert_emitted_single(self, from_address, expected_event)++`]
+* xref:#testing-events-drop_event[`++drop_event(self)++`]
+* xref:#testing-events-drop_n_events[`++drop_n_events(self, number_to_drop)++`]
+* xref:#testing-events-drop_all_events[`++drop_all_events(self)++`]
+* xref:#testing-events-assert_no_events_left[`++assert_no_events_left(self)++`]
+* xref:#testing-events-assert_no_events_left_from[`++assert_no_events_left_from(self, from_address)++`]
+* xref:#testing-events-count_events_from[`++count_events_from(self, from_address)++`]
+--
+
+[#testing-events-Functions]
+==== Functions
+
+[.contract-item]
+[[testing-events-assert_only_event]]
+==== `[.contract-item-name]#++assert_only_event++#++<T, +starknet::Event<T>, +Drop<T>>(ref self: EventSpy, from_address: ContractAddress, expected_event: T)++` [.item-kind]#function#
+
+Ensures that `from_address` has emitted only the `expected_event` and no additional events.
+
+[.contract-item]
+[[testing-events-assert_emitted_single]]
+==== `[.contract-item-name]#++assert_emitted_single++#++<T, +starknet::Event<T>, +Drop<T>>(ref self: EventSpy, from_address: ContractAddress, expected_event: T)++` [.item-kind]#function#
+
+Ensures that `from_address` has emitted the `expected_event`.
+
+[.contract-item]
+[[testing-events-drop_event]]
+==== `[.contract-item-name]#++drop_event++#++(ref self: EventSpy)++` [.item-kind]#function#
+
+Removes a single event from the queue. If the queue is empty, the function will panic.
+
+[.contract-item]
+[[testing-events-drop_n_events]]
+==== `[.contract-item-name]#++drop_n_events++#++(ref self: EventSpy, number_to_drop: u32)++` [.item-kind]#function#
+
+Removes `number_to_drop` events from the queue. If the queue is empty, the function will panic.
+
+[.contract-item]
+[[testing-events-drop_all_events]]
+==== `[.contract-item-name]#++drop_all_events++#++(ref self: EventSpy)++` [.item-kind]#function#
+
+Removes all events remaining on the queue. If the queue is empty already, the function will do nothing.
+
+[.contract-item]
+[[testing-events-assert_no_events_left]]
+==== `[.contract-item-name]#++assert_no_events_left++#++(ref self: EventSpy)++` [.item-kind]#function#
+
+Ensures that there are no events remaining on the queue.
+
+[.contract-item]
+[[testing-events-assert_no_events_left_from]]
+==== `[.contract-item-name]#++assert_no_events_left_from++#++(ref self: EventSpy, from_address: ContractAddress)++` [.item-kind]#function#
+
+Ensures that there are no events emitted from the given address remaining on the queue.
+
+[.contract-item]
+[[testing-events-count_events_from]]
+==== `[.contract-item-name]#++count_events_from++#++(ref self: EventSpy, from_address: ContractAddress) → u32++` [.item-kind]#function#
+
+Counts the number of remaining events emitted from the given address.
+
+[.contract]
+[[testing-signing]]
+=== `++signing++`
+
+```cairo
+use openzeppelin_testing::signing;
+```
+
+A module offering utility functions for easier management of key pairs and signatures.
+
+[.contract-index]
+.Members
+--
+.Functions
+* xref:#testing-signing-get_stark_keys_from[`++get_stark_keys_from(private_key)++`]
+* xref:#testing-signing-get_secp256k1_keys_from[`++get_secp256k1_keys_from(private_key)++`]
+
+.Traits
+* xref:#testing-signing-SerializedSigning[`++SerializedSigning++`]
+--
+
+[#testing-signing-Functions]
+==== Functions
+
+[.contract-item]
+[[testing-signing-get_stark_keys_from]]
+==== `[.contract-item-name]#++get_stark_keys_from++#++(private_key: felt252) → StarkKeyPair++` [.item-kind]#function#
+
+Builds a {stark} key pair from a private key represented by a `felt252` value.
+
+[.contract-item]
+[[testing-signing-get_secp256k1_keys_from]]
+==== `[.contract-item-name]#++get_secp256k1_keys_from++#++(private_key: u256) → Secp256k1KeyPair++` [.item-kind]#function#
+
+Builds a {secp256k1} key pair from a private key represented by a `u256` value.
+
+[#testing-signing-Traits]
+==== Traits
+
+[.contract-item]
+[[testing-signing-SerializedSigning]]
+==== `[.contract-item-name]#++SerializedSigning++#` [.item-kind]#trait#
+
+A helper trait that facilitates signing and converting the result signature into a serialized format.
+
+Usage example:
+
+```cairo
+use openzeppelin_testing::signing::{
+    StarkKeyPair, get_stark_keys_from, StarkSerializedSigning
+};
+
+let key_pair = get_stark_keys_from('SECRET_KEY');
+let serialized_signature = key_pair.serialized_sign('TX_HASH');
+```