vercel/next.js

ISG with GIP in _app overrides cache-control of ISG page

Open

#14244 opened on Jun 16, 2020

View on GitHub
 (3 comments) (0 reactions) (1 assignee)JavaScript (139,471 stars) (31,066 forks)batch import
Pages Routergood first issuetype: next

Description

Bug report

When using the unstable_revalidate param with ISG, a header set by _app should never win.

Additional context

From @lfades:

Update: this is currently not the case, SSG finishes the request before it gets to _app.

the custom _app in the Next.js site was setting a header, but that causes an error because the request was sent, this happens in production and with next start, but in dev you don't get any error.

Contributor guide

Tech stack
nextjsreactjavascripttypescript
Domain
full stack
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Next.jsISGgetInitialPropscache control
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate how Next.js handles cache control headers when using ISG with getInitialProps in app. Look at the source files related to ISG, such as next server and router. A minimal reproduction would help confirm the issue. Check if there are existing tests for this scenario in the Next.js test suite.