LmTest is a testing framework for exploring the security impact of future microarchitectural optimizations by automatically detecting leaks in cryptographic implementations. For this, LmTest is parametric in a given leakage that captures, at program level, what information might be leaked by the proposed microarchitectural optimization. LmTest supports leakage models formalized in the LmSpec language, an expressive domain-specific language supporting the specification of leakage clauses (capturing which information is leaked) and prediction clauses (which specifies the prediction mechanism supported by the microarchitecture and what their effects are). This repository is a snapshot of the artifact associated with the CCS 2024 paper "Testing side-channel security of cryptographic implementations against future microarchitectures". The live version of this repository is available at https://github.com/hw-sw-contracts/leakage-model-testing.