miden-testing 0.16.0-alpha.2

// TRANSACTION CONTEXT BUILDER
// ================================================================================================

use alloc::collections::BTreeMap;
use alloc::sync::Arc;
use alloc::vec::Vec;

use anyhow::Context;
use miden_processor::advice::AdviceInputs;
use miden_processor::{Felt, Word};
use miden_protocol::EMPTY_WORD;
use miden_protocol::account::auth::{PublicKeyCommitment, Signature};
use miden_protocol::account::{Account, AccountHeader, AccountId};
use miden_protocol::assembly::DefaultSourceManager;
use miden_protocol::assembly::debuginfo::SourceManagerSync;
use miden_protocol::block::account_tree::AccountWitness;
use miden_protocol::note::{Note, NoteId, NoteScript, NoteScriptRoot};
use miden_protocol::transaction::{
    RawOutputNote,
    TransactionArgs,
    TransactionInputs,
    TransactionScript,
};
use miden_tx::TransactionMastStore;
use miden_tx::auth::BasicAuthenticator;

use super::TransactionContext;
use crate::MockChain;

// TRANSACTION CONTEXT BUILDER
// ================================================================================================

/// [TransactionContextBuilder] is a utility to construct [TransactionContext] for testing
/// purposes. It allows users to build accounts, create notes, provide advice inputs, and
/// execute code. The VM process can be inspected afterward.
///
/// # Examples
///
/// Create a transaction context for an existing account and execute code:
/// ```
/// # use anyhow::Result;
/// # use miden_protocol::Felt;
/// # use miden_testing::{Auth, MockChain};
/// #
/// # #[tokio::main(flavor = "current_thread")]
/// # async fn main() -> Result<()> {
/// let mut builder = MockChain::builder();
/// let account = builder.add_existing_mock_account(Auth::IncrNonce)?;
/// let mock_chain = builder.build()?;
/// let tx_context = mock_chain.build_tx_context(account.id(), &[], &[])?.build()?;
///
/// let code = "
/// use miden::tx_kernel_core::prologue
///
/// begin
///     exec.prologue::prepare_transaction
///     push.5
///     swap drop
/// end
/// ";
///
/// let exec_output = tx_context.execute_code(code).await?;
/// assert_eq!(exec_output.stack.get(0).unwrap(), &Felt::from(5u32));
/// # Ok(())
/// # }
/// ```
#[derive(Clone)]
pub struct TransactionContextBuilder {
    source_manager: Arc<dyn SourceManagerSync>,
    account: Account,
    advice_inputs: AdviceInputs,
    authenticator: Option<BasicAuthenticator>,
    expected_output_notes: Vec<Note>,
    foreign_account_inputs: BTreeMap<AccountId, (Account, AccountWitness)>,
    input_notes: Vec<Note>,
    tx_script: Option<TransactionScript>,
    tx_script_args: Word,
    note_args: BTreeMap<NoteId, Word>,
    tx_inputs: Option<TransactionInputs>,
    auth_args: Word,
    signatures: Vec<(PublicKeyCommitment, Word, Signature)>,
    note_scripts: BTreeMap<NoteScriptRoot, NoteScript>,
    is_lazy_loading_enabled: bool,
}

impl TransactionContextBuilder {
    pub fn new(account: Account) -> Self {
        Self {
            source_manager: Arc::new(DefaultSourceManager::default()),
            account,
            input_notes: Vec::new(),
            expected_output_notes: Vec::new(),
            tx_script: None,
            tx_script_args: EMPTY_WORD,
            authenticator: None,
            advice_inputs: Default::default(),
            tx_inputs: None,
            note_args: BTreeMap::new(),
            foreign_account_inputs: BTreeMap::new(),
            auth_args: EMPTY_WORD,
            signatures: Vec::new(),
            note_scripts: BTreeMap::new(),
            is_lazy_loading_enabled: true,
        }
    }

    /// Extend the advice inputs with the provided [AdviceInputs] instance.
    pub fn extend_advice_inputs(mut self, advice_inputs: AdviceInputs) -> Self {
        self.advice_inputs.extend(advice_inputs);
        self
    }

    /// Extend the advice inputs map with the provided iterator.
    pub fn extend_advice_map(
        mut self,
        map_entries: impl IntoIterator<Item = (Word, Vec<Felt>)>,
    ) -> Self {
        self.advice_inputs.map.extend(map_entries);
        self
    }

    /// Set the authenticator for the transaction (if needed)
    pub fn authenticator(mut self, authenticator: Option<BasicAuthenticator>) -> Self {
        self.authenticator = authenticator;
        self
    }

    /// Set foreign account codes that are used by the transaction
    pub fn foreign_accounts(
        mut self,
        inputs: impl IntoIterator<Item = (Account, AccountWitness)>,
    ) -> Self {
        self.foreign_account_inputs.extend(
            inputs.into_iter().map(|(account, witness)| (account.id(), (account, witness))),
        );
        self
    }

    /// Set the desired transaction script
    pub fn tx_script(mut self, tx_script: TransactionScript) -> Self {
        self.tx_script = Some(tx_script);
        self
    }

    /// Set the transaction script arguments
    pub fn tx_script_args(mut self, tx_script_args: Word) -> Self {
        self.tx_script_args = tx_script_args;
        self
    }

    /// Set the desired auth arguments
    pub fn auth_args(mut self, auth_args: Word) -> Self {
        self.auth_args = auth_args;
        self
    }

    /// Set the desired transaction inputs
    pub fn tx_inputs(mut self, tx_inputs: TransactionInputs) -> Self {
        assert_eq!(
            AccountHeader::from(&self.account),
            tx_inputs.account().into(),
            "account in context and account provided via tx inputs are not the same account"
        );
        self.tx_inputs = Some(tx_inputs);
        self
    }

    /// Disables lazy loading.
    ///
    /// Only affects [`TransactionContext::execute_code`] and causes the host to _not_ handle lazy
    /// loading events.
    pub fn disable_lazy_loading(mut self) -> Self {
        self.is_lazy_loading_enabled = false;
        self
    }

    /// Extend the note arguments map with the provided one.
    pub fn extend_note_args(mut self, note_args: BTreeMap<NoteId, Word>) -> Self {
        self.note_args.extend(note_args);
        self
    }

    /// Extend the expected output notes.
    pub fn extend_expected_output_notes(mut self, output_notes: Vec<RawOutputNote>) -> Self {
        let output_notes = output_notes.into_iter().filter_map(|n| match n {
            RawOutputNote::Full(note) => Some(note),
            RawOutputNote::Partial(_) => None,
        });

        self.expected_output_notes.extend(output_notes);
        self
    }

    /// Sets the [`SourceManagerSync`] on the [`TransactionContext`] that will be built.
    ///
    /// This source manager should contain the sources of all involved scripts and account code in
    /// order to provide better error messages if an error occurs.
    pub fn with_source_manager(mut self, source_manager: Arc<dyn SourceManagerSync>) -> Self {
        self.source_manager = source_manager.clone();
        self
    }

    /// Add a new signature for the message and the public key.
    pub fn add_signature(
        mut self,
        pub_key: PublicKeyCommitment,
        message: Word,
        signature: Signature,
    ) -> Self {
        self.signatures.push((pub_key, message, signature));
        self
    }

    /// Add a note script to the context for testing.
    pub fn add_note_script(mut self, script: NoteScript) -> Self {
        self.note_scripts.insert(script.root(), script);
        self
    }

    /// Builds the [TransactionContext].
    ///
    /// If no transaction inputs were provided manually, an ad-hoc MockChain is created in order
    /// to generate valid block data for the required notes.
    pub fn build(self) -> anyhow::Result<TransactionContext> {
        let mut tx_inputs = match self.tx_inputs {
            Some(tx_inputs) => tx_inputs,
            None => {
                // If no specific transaction inputs was provided, initialize an ad-hoc mockchain
                // to generate valid block header/MMR data

                let mut builder = MockChain::builder();

                // Get the set of note IDs in the provided order.
                let input_note_ids: Vec<NoteId> = self.input_notes.iter().map(Note::id).collect();

                for input_note in self.input_notes {
                    builder.add_output_note(RawOutputNote::Full(input_note));
                }
                let mut mock_chain = builder.build()?;

                mock_chain.prove_next_block().context("failed to prove first block")?;
                mock_chain.prove_next_block().context("failed to prove second block")?;

                mock_chain
                    .get_transaction_inputs(&self.account, &input_note_ids, &[])
                    .context("failed to get transaction inputs from mock chain")?
            },
        };

        let mut tx_args = TransactionArgs::default().with_note_args(self.note_args);

        tx_args = if let Some(tx_script) = self.tx_script {
            tx_args.with_tx_script_and_args(tx_script, self.tx_script_args)
        } else {
            tx_args
        };
        tx_args = tx_args.with_auth_args(self.auth_args);
        tx_args.extend_advice_inputs(self.advice_inputs.clone());
        tx_args.extend_output_note_recipients(self.expected_output_notes.clone());

        for (public_key_commitment, message, signature) in self.signatures {
            tx_args.add_signature(public_key_commitment, message, signature);
        }

        tx_inputs.set_tx_args(tx_args);

        let mast_store = {
            let mast_forest_store = TransactionMastStore::new();
            mast_forest_store.load_account_code(tx_inputs.account().code());

            for (account, _) in self.foreign_account_inputs.values() {
                mast_forest_store.load_account_code(account.code());
            }

            mast_forest_store
        };

        Ok(TransactionContext {
            account: self.account,
            expected_output_notes: self.expected_output_notes,
            foreign_account_inputs: self.foreign_account_inputs,
            tx_inputs,
            mast_store,
            authenticator: self.authenticator,
            source_manager: self.source_manager,
            note_scripts: self.note_scripts,
            is_lazy_loading_enabled: self.is_lazy_loading_enabled,
        })
    }
}