src/models/conflict.js
function getChange(parent, sha) {
    if (parent === sha) {
        return CHANGE.IDENTICAL;
    } else if (parent === null) {
        return CHANGE.ADDED;
    } else if (sha === null) {
        return CHANGE.DELETED;
    } else {
        // Both are not null but different
        return CHANGE.MODIFIED;
    }
}
function getChange(parent, sha) {
    if (parent === sha) {
        return CHANGE.IDENTICAL;
    } else if (parent === null) {
        return CHANGE.ADDED;
    } else if (sha === null) {
        return CHANGE.DELETED;
    } else {
        // Both are not null but different
        return CHANGE.MODIFIED;
    }
}
---- utils ---- 
@param {SHA | Null} parent
@param {SHA | Null} sha
@return {Conflict.CHANGE}