`v8.writeHeapSnapshot` may return `undefined` if the file fails to write
Version
v16.13.1
Platform
Linux bd035f8a23f8 4.19.0-18-amd64 # 1 SMP Debian 4.19.208-1 (2021-09-29) x86_64 GNU/Linux
Subsystem
v8
What steps will reproduce the bug?
Call v8.writeHeapSnapshot() on a folder where the process has no permissions to write to (e.g. inside a Docker container, example dockerfile below).
Sample files
package.json
{
"main": "index.js",
"scripts": {
"start": "node ."
}
}Dockerfile
FROM node:16-buster-slim WORKDIR /usr/src/app COPY --chown=node:node package.json . COPY --chown=node:node index.js . USER node CMD [ "npm", "run-script", "start" ]
This will cause the following code, which returns early (and thus, returning undefined):
| if (!WriteSnapshot(isolate, *path)) | |
| return; |
As the code the line below (which sets the return value) is not executed:
| return args.GetReturnValue().Set(filename_v); |
How often does it reproduce? Is there a required condition?
Always, requires the module to attempt to write in a folder without write permissions.
What is the expected behavior?
Either to throw an error (permissions error, out of space, etc) or to document that it may return undefined
What do you see instead?
The documentation specifies that it returns a string and does not mention that it may return undefined.
Additional information
No response