Yarn workspaces parallel run

workspaces-parallel.js

const {exec, execSync} = require('child_process');
const util = require('util');

const asyncExec = util.promisify(exec);

const red = (str) => util.format('\x1b[31m%s\x1b[0m', str);
const green = (str) => util.format('\x1b[32m%s\x1b[0m', str);
const magenta = (str) => util.format('\x1b[35m%s\x1b[0m', str);

// @example package.json
// { "scripts": { "workspaces:parallel": "node ./workspaces-parallel.js" } }
async function main() {
    const args = process.argv.slice(2);
    const [taskName, ...taskOptionsArr] = args;

    if (!taskName) {
        console.log('  Usage: yarn run workspaces:parallel <taskName> [taskOptions]');
        console.log('  example: yarn run workspaces:parallel test');
        console.log('  example: yarn run workspaces:parallel tsc --noEmit');
        process.exit(1);
    }

    const taskOptions = taskOptionsArr.join(' ');

    // `yarn workspaces info` -> { "@example/name": { "location": "packages/name", ... }, ...}
    const workspacesInfoRaw = execSync('yarn workspaces info').toString();
    const workspacesInfo = JSON.parse(workspacesInfoRaw);
    const workspaces = Object.keys(workspacesInfo);

    console.log('Running', green(taskName), `against ${workspaces.length} workspaces...\n`);

    // Spawn `exec` calls for every workspace at the same time.
    const workspaceExecs = workspaces.map((workspace) => {
        const taskCommand = [taskName, taskOptions].filter(Boolean).join(' ');
        const command = `yarn workspace ${workspace} run ${taskCommand}`;

        console.log(command);

        return asyncExec(command)
            .then((result) => {
                console.log(result.stdout);
                if (result.stderr) {
                    console.error(result.stderr);
                }

                return result;
            })
            .catch((err) => {
                // Only log error and don't rethrow. Inspecting exit codes at the end allow us to report failures
                console.log(red('[START ERROR]'), magenta(workspace));
                console.log(err.stdout);
                console.log(red('[END ERROR]'), magenta(workspace));

                // Returned errors have a `.code` property
                return err;
            });
    });

    const results = await Promise.all(workspaceExecs);

    for (let result of results) {
        // Successful results don't have a `.code` property
        const resultExitCode = result.code ?? 0;

        if (resultExitCode > 0) {
            /**
             * Exit early since all results have already been reported.
             * A non-zero exit code will be reported as a failure in CI
             */
            process.exit(resultExitCode);
        }
    }

    // If we made it here, all results exited with an exit code of 0, we are good!
    process.exit(0);
}

main();