Mina Batch Reducer Example - Counter

This repository provides a minimal example demonstrating the use of the BatchReducer functionality in the Mina Protocol, as presented in o1-labs/o1js PR #1676. The example implements a simple counter smart contract that accumulates a running total of values submitted in batches using Mina’s BatchReducer. This example also includes tests to verify the correct behavior of the counter and batch reducer.

Getting Started

Installation

1. Clone the repository:

   git clone https://github.com/your-username/mina-batch-reducer-counter.git
   cd mina-batch-reducer-counter

2. Install dependencies:

   npm install

Code Overview

Smart Contract

The Add smart contract maintains a running total of values added through batch processing.

• State Variables:

  • totalSum: Stores the accumulated total.
  • actionState and actionStack: Used by the batch reducer to maintain the state and action stack for batching.

• Methods:

  • add(value: Field): Dispatches an action to add a non-negative value to the total.
  • batchReduce(batch: Batch, proof: BatchProof): Processes a batch of actions, updating totalSum by adding values from the batch.

Test

The test file verifies the correct behavior of the Add contract:

• Deploys the contract locally on a Mina test network.
• Dispatches multiple actions and then reduces them in batches.
• Asserts that totalSum reflects only the values processed through the batch reducer.
• Confirms that the actions are processed only once by checking totalSum after multiple reductions.

Running the Tests

To run the tests, use the following command:

npm test

The tests will:

1. Deploy the Add contract and verify the initial state.
2. Dispatch actions and perform batch reduction.
3. Verify that totalSum is updated as expected after each batch reduction.