问处理nodejs承诺的最佳方式

EN

- In `session.then(...)`, `session.close();` will never execute after the `return` statement.
- You don't have to embed the `session.run(...)` logic in `query()`. Also, if `session.run().then().catch()` will return a `Promise`, you can just return it directly instead of initializing a new promise and resolving/rejecting explicitly.
- `error` in `session.catch(...)` should be handled by `deferred.reject` as well instead of just logging it to console.
- If you are not using the ancient Node.js, it should have native promise, you don't have to use "Q".

getManager : function (fullname) {
    // ideally, `fullname` should be checked before calling this function
    // if this function is only for private use and totally controllable.
    if (fullname) {
        // only initialize variables when necessary
        const returnResults = [];
        const session = graphDBDriver.session();
        const cypherQuery = "Neo4j Query";
        return session
            .run(cypherQuery, {
                fullname: fullname
            })
            .then(function(result) {
                result.records.forEach(function(record) {
                    if (record && record.length >= 1) {
                        returnResults.push(record);
                    }
                });
                session.close();
                // `return value` in `.then()` is similar to `resolve(value)`
                return returnResults;
            })
            .catch(function(error) {
                session.close();
                console.log(" Neo4j error from getManager: " + error);
                // `throw value` in `.catch()` is similar to `reject(value)`
                // throw it so that it can be caught
                throw error;
            });
    } else {
        const error = new Error('`fullname` is required');
        // always return a promise
        return Promise.reject(error);
    }
}