Simplex v0.2.0

Release notes v0.2.0 🎉

• Added simplex fmt to format SimplicityHL sources with simfmt, which simplexup now installs.
• Rewrote fuzz testing to a much more versatile and smart suite.
• Made every command find Simplex.toml in the current directory or any of its ancestors.

fuzz

• Replaced the single-program fuzz engine with Scenario, a transaction template where each program spends inputs and locks outputs.
• Added bind_arguments and bind_witness to derive values from the case, and requires_witness for values the fuzzer also violates to check that the contract rejects them.
• Added spec to state when a case must be accepted, rejected or either, read from FuzzCase.
• Added transaction Mutations of amounts, assets, timelocks and layout, applied to the template's targeted inputs and outputs.
• Added lock and authorization smart checks that redirect locked outputs and replay signatures from a wrong key.
• Added spending_path and storage_capacity to the program builder, and random_strategy and custom_strategy to replace the guided default.
• Added a run summary of verdicts, rejections, spec predictions, violations, mutations and smart checks.
• Removed FuzzableProgram, FuzzTransaction, ArgsStrategyBuilder, ProgramCheck and FuzzError.

sdk

• Replaced RequiredSignature arguments with Option<NativeSignature> for native inputs and Option<ProgramSignature> for program inputs, built as ProgramSignature::new(name).at_path(path).tagged(tag).
• Made Signer sign only inputs that request a native signature and refuse a key that doesn't own a P2WPKH input.
• Made Signer derive its keys and addresses once, and reuse one sighash cache per transaction.
• Reduced how often coin selection signs the transaction.
• Fixed coin selection: skip UTXOs listed twice, skip confidential UTXOs for an explicit change target, and keep blinded change that would reveal a blinded amount.
• Fixed fees: report the whole leftover as the fee when change is dropped, and fold explicit change below the 22 sat dust threshold into the fee.
• Made a set locktime enforced by default, by giving inputs without a sequence ENABLE_LOCKTIME_NO_RBF.
• Made per-input sequence and locktime optional, so an explicit Sequence::MAX or LockTime::ZERO is kept.
• Made get_utxos skip outputs the wallet can't unblind, instead of failing.
• Replaced panics with errors for unknown input amounts, amount overflows, invalid fee rates, duplicate inputs, empty issuances, unblinded reissuance tokens, inputs without a witness UTXO and invalid derivation paths.
• Fixed token-only issuance by encoding a zero asset amount as null.
• Added FinalTransaction::sequence and locktime getters.
• Added Program::set_storage, get_arguments and MAX_STORAGE_SLOTS, and capped storage at 128 slots.
• Made SimplexProvider::broadcast_transaction wait until Esplora indexes the transaction.
• Cached the program's CMR, witness types and taproot spend info.

build

• Refused a dependency src_dir that resolves outside its package.
• Refused an out_dir that holds the project or its src_dir, in both build and clean.
• Refused source directories that aren't Rust identifiers, before writing any artifact.
• Warned about .simf files that don't parse, instead of skipping them silently.

install

• Resolved tags and branches by their full ref.
• Made git dependency directory names unambiguous.
• Made installs atomic, and reported an incomplete dependency instead of treating it as installed.

init

• Made simplex init optimize dependencies in dev builds, which speeds up tests.

wasm

• Rejected issuances of zero, reissuance tokens with a zero blinding factor, derivation paths other than m/n, and more than 128 extra leaves.

simplexup

• Verified binaries before installing them and refused versions whose install didn't complete.
• Verified the attestation's signer with gh when the GitHub CLI is installed and logged in.
• Installed --commit builds as their own version.
• Made --use switch every binary to the chosen version.