mongoose-query-logger/src/logger.ts

   ![license](https://badgen.net/npm/license/mongoos

import chalk from 'chalk';

import { getWinningPlan } from './explain';
import { ExplainLoggerArgs, QueryLoggerArgs } from './types';
import { isEmpty } from './utils';

const SERIALIZE_ARRAY_MAX_LEN = 100;

// cut extremely long arrays in query serialization
function arrayMaxLengthReplacer(key: string, value: any) {
  if (Array.isArray(value) && value.length > SERIALIZE_ARRAY_MAX_LEN) {
    return value
      .slice(0, SERIALIZE_ARRAY_MAX_LEN)
      .concat(`${value.length - SERIALIZE_ARRAY_MAX_LEN} more items...`);
  }
  return value;
}

function stringify(obj: any, space?: string | number) {
  return JSON.stringify(obj, arrayMaxLengthReplacer, space);
}

export const defaultQueryLogger = (
  {
    operation,
    collectionName,
    executionTimeMS,
    filter,
    fields,
    options,
    update,
    additionalLogProperties,
  }: QueryLoggerArgs,
  logger = console.log
) => {
  let logProperties: any = {};

  if (update) {
    logProperties.update = update;
  }

  if (additionalLogProperties) {
    logProperties = logProperties
      ? { ...logProperties, additionalLogProperties }
      : { additionalLogProperties };
  }

  const otherArgs = [update, fields, options]
    .map(x => (x && !isEmpty(x) ? stringify(x) : null))
    .filter(x => x);
  const queryArgs = [stringify(filter)].concat(otherArgs).join(', ');

  const queryString = `${collectionName}.${operation}(${queryArgs})`;

  logger(`mongoose: ${logTimeMS(executionTimeMS)} ms ${queryString}`);
};

export const defaultExplainLogger = (
  { queryPlanners }: ExplainLoggerArgs,
  logger = console.log
) => {
  queryPlanners.forEach(queryPlanner => {
    const stages = getWinningPlan(queryPlanner);
    const plan = logQueryExplain(stages);
    if (plan) {
      logger(plan);
    }
  });
};

function logTimeMS(executionTimeMS: number) {
  if (executionTimeMS < 100) {
    return chalk.green(executionTimeMS);
  }
  if (executionTimeMS < 1000) {
    return chalk.yellow(executionTimeMS);
  }
  return chalk.red(executionTimeMS);
}

function logQueryExplain(stages): string | null {
  if (!stages || stages.length === 0) {
    return null;
  }

  const firstStage = stages[0];

  if (firstStage.stage === 'IDHACK') {
    return null; // ignore id lookups to avoid flooding
  }

  if (firstStage.stage === 'IXSCAN') {
    return chalk.green(`IXSCAN ${stringify(firstStage.keyPattern)}`);
  }

  if (firstStage.stage === 'COLLSCAN') {
    return chalk.red(`COLLSCAN: ${stringify(stages, 4)}`);
  }

  return chalk.yellow(`Stages: ${stringify(stages, 4)}`);
}