analyze-tsc-trace-longest-checkSourceFile

analyze-trace.mjs

import * as fsp from 'fs/promises';
import { dirname } from 'path';
import { fileURLToPath } from 'url';

// eslint-disable-next-line no-underscore-dangle
const __dirname = dirname(fileURLToPath(import.meta.url));
const dirNameLen = __dirname.length;

const file = await fsp.readFile('../trace.json');
const trace = JSON.parse(file);

const infoByFile = {};

for (const entry of trace) {
    if (entry.name !== 'checkSourceFile') {
        continue;
    }
    if (entry.ph === 'B') {
        infoByFile[entry.args.path] = {};
        infoByFile[entry.args.path].startTs = entry.ts;
    }
    if (entry.ph === 'E') {
        infoByFile[entry.args.path].endTs = entry.ts;
    }
}

const filesAndDurations = [];
Object.keys(infoByFile).forEach(filePath => {
    const info = infoByFile[filePath];
    const durationSeconds = Math.floor(info.endTs - info.startTs) / 1_000_000;
    filesAndDurations.push({
        filePath,
        durationSeconds
    });
});

filesAndDurations.sort((a, b) => b.durationSeconds - a.durationSeconds);
const topFiles = filesAndDurations.slice(0, 10);

for (const entry of topFiles) {
    console.log(
        `${entry.durationSeconds.toFixed(2)}s: ${entry.filePath.slice(
            dirNameLen
        )}`
    );
}