@essex/redux-dag-history/lib/DagHistory/getExistingState.js

"use strict";
var DagGraph_1 = require("../DagGraph");
var log = require('debug')('redux-dag-history:DagHistory');
function getExistingState(newState, history, config) {
    if (config.stateKeyGenerator && config.stateEqualityPredicate) {
        var dagGraph = new DagGraph_1.default(history.graph);
        var hash = config.stateKeyGenerator(newState);
        var found = dagGraph.getStateForHash(hash);
        if (found) {
            var existingState = new DagGraph_1.default(history.graph)
                .getState(found);
            var areEqual = config.stateEqualityPredicate(newState, existingState);
            if (areEqual) {
                return found;
            }
            log('found hashed state not equal');
        }
        else {
            log('no hashed state found');
        }
    }
    else {
        log('skip existing state check');
    }
    return null;
}
Object.defineProperty(exports, "__esModule", { value: true });
exports.default = getExistingState;