yarnpkg/yarn

Multiple sub-scripts do not output progressively

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#4.423 geöffnet am 12. Sept. 2017

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Beschreibung

I have package.json scripts like this:

"scripts": {
    "lint:all": "yarn run lint:project-a && yarn run lint:project-b && yarn run lint:project-c",
    "lint:project-a": "cd project-a && yarn run lint",
    "lint:project-b": "cd project-b && yarn run lint",
    "lint:project-c": "cd project-c && yarn run lint"
}

This is the output from npm@5.4 which is what I would say is "expected":

$ npm run lint:all

> example@1.0.0 lint:all c:\dev\example
> yarn run lint:project-a && yarn run lint:project-b && yarn run lint:project-c

yarn run v1.0.1
$ cd project-a && yarn run lint
Done in 8.34s.
yarn run v1.0.1
$ cd project-b && yarn run lint
Done in 8.26s.
yarn run v1.0.1
$ cd project-c && yarn run lint
Done in 10.57s.

Yarn produces this:

$ yarn run lint:all
yarn run v1.0.1
$ yarn run lint:project-a && yarn run lint:project-b && yarn run lint:project-c
Done in 48.05s.

and the wait is quite long. Is this expected behavior or possibly a bug?

Node 8.4.0, Yarn 1.0.1, Windows 10

Contributor Guide

Tech Stack
javascriptnodejs
Domain
cli
Issue Type
bug
SchwierigkeitGeschätzte Implementierungsschwierigkeit für neue Contributors, von 1 für sehr kleine Änderungen bis 5 für Expertenarbeit.
3
Geschätzte ZeitEin grober Zeitrahmen, um zu recherchieren, zu implementieren, zu testen und einen Pull Request vorzubereiten.
3-5 days
AktivitätsstatusWie verfügbar das Issue gerade wirkt: frisch, aktiv, stale, blockiert oder wartet auf Maintainer-Input.
stale
KlarheitWie klar das Issue die erwartete Änderung, Akzeptanzkriterien und den nächsten Schritt erklärt.
mostly clear
Voraussetzungen
basic understanding of yarnfamiliarity with child process streams
EinsteigerfreundlichkeitEin Score von 1 bis 100, der schätzt, wie zugänglich dieses Issue für First-Time Contributors ist.
20
Research-Richtung
The issue reports that when running multiple sub scripts sequentially with `&&`, Yarn buffers all output and displays it only after all scripts finish, unlike npm which shows output progressively. Investigate how Yarn spawns child processes and handles their stdout/stderr streams. Look in the `src/util/execute lifecycle script.js` or similar files for how output is collected and flushed. Check if there's a way to inherit the parent process's stdio to achieve progressive output. Note that the repository (1.x line) is frozen, so any fix would likely need to target the 2.x line at https://github.com/yarnpkg/berry.