Find slow appium commands

slow-appium-commands.js

// Usage:
//   node ./slow-appium-commands.js <log file>
//
// If your logs contain ANSI colour tags (ie downloaded from semaphore), first strip with
//   sed -r "s/\x1B\[(([0-9]+)(;[0-9]+)*)?[m,K,H,f,J]//g" <log file>

const fs = require("fs");

// any webdriver commands which took longer than this will be logged
const THRESHOLD = 5000; // ms

if (process.argv.length !== 3) {
  console.log("expected path to log file");
  process.exit(-1);
}

const path = process.argv[2];
let logs = fs.readFileSync(path, { encoding: "utf8" }).split("\n");

let previousTimestamp = undefined;
let previousLine = undefined;

const searching = logs
  .map((line, index) => {
    return { index, match: line.indexOf("Connected: http") !== -1 };
  })
  .filter((result) => result.match);

// ignore everything up to the last occurrence of a particular string, which should roughly correspond to the app loaded & the interesting part of the test starting
const startIndex = searching[searching.length - 1].index;
logs = logs.slice(startIndex);

logs.forEach((line, i) => {
  const lineNumber = startIndex + i;

  if (line.indexOf("webdriver") === -1) {
    // only interested in lines logged by the webdriver
    return;
  }

  const split = line.trim().split(" ");
  const timestamp = new Date(split[0]);

  if (previousTimestamp) {
    const ms = timestamp.valueOf();
    const duration = ms - previousTimestamp.valueOf();

    // check for particularly large time gaps between logs
    if (duration > THRESHOLD) {
      console.log(`==== Slow… line ${lineNumber}: took ${duration}ms\n`);
      console.log(previousLine);

      // log the next command invoked… this may have printed some formatted json, so is a little tricky. print up to next occurrence of webdriver, if found

      const remainingLogs = logs.slice(i).map((line, index) => ({ line, index }));
      const next = remainingLogs
        .slice(1) // skip the first line (it will contain 'webdriver')
        .find((line) => line.line.indexOf("webdriver") !== -1);

      const endIndex = next?.index ?? 1;
      console.log(
        remainingLogs
          .slice(0, endIndex)
          .map((line) => line.line)
          .join("\n")
      );
      console.log("\n\n");
    }
  }

  previousTimestamp = timestamp;
  previousLine = line;
});