@bitgo/unspents

The package provides a Dimensions class with methods to calculate bitcoin transaction sizes

Installation

npm install --save @bitgo/unspents

Dimensions, Virtual Size Estimation

The transaction vSize is critical to calculating the proper transaction fee.

The class unspents.Dimensions provides a class that helps work with the components required to calculate an accurate estimate of a transaction vSize.

Examples

import { Codes, Dimensions } from '@bitgo/unspents';
// using raw attributes
new Dimensions({
  nP2shInputs: 1,
  nP2shP2wshInputs: 1,
  nP2wshInputs: 1,
  outputs: { count: 1, size: 32 },
});

// calculate from unspents that have `chain` property (see Chain Codes)
Dimensions.fromUnspents(unspent[0]);
Dimensions.fromUnspents(unspents);

// Signed inputs work too
Dimensions.fromInput(inputs[0]);
Dimensions.fromInputs(inputs);

// Transaction outputs
Dimensions.fromOutputs(outputs[0]);
Dimensions.fromOutputs(outputs);
Dimensions.fromOutputOnChain(Codes.p2sh.internal);
Dimensions.fromOutputScriptLength(31);

// Combining dimensions and estimating their vSize
Dimensions.fromUnspents({ unspents })
  .plus(Dimensions.fromOutputOnChain(Codes.p2shP2wsh.internal).times(nOutputs))
  .getVSize();

Publishing new versions

Publishing new versions should be done by running the publish script in scripts/publish.sh.

It can be invoked with the name of the branch to release, and will default to the currently checked out branch if not given.

It will perform validation of all prepublish conditions, run a dry-run publish, then, if successful, a real publish. After that is complete, the newly installed package will be downloaded and require()'d to ensure the package was published correctly.

Continuous Integration

@bitgo/unspents uses Drone for continuous integration, which is configured by the .drone.yml file in the project root. However, this file should not be modified by hand. All changes to the CI process should be done by modifying the .drone.jsonnet file, then running npm run generate_drone to rebuild the .drone.yml file.

Codes

The exported Codes module is now deprecated.

Please use utxo-lib/src/bitgo/wallet/chains instead.