child_process.fork not passing along options.env

[borisovg]

• Version: v8.11.1
• Platform: Linux
• Subsystem: Child Process

parent.js:

require('child_process').fork('./child.js', undefined, { env: { FOO: 'bar' } });

child.js

console.log(process.env.FOO);

output:

$ FOO=foo node parent.js 
foo

[vsemozhetbyt]

Try:

require('child_process').fork('./child.js', [], { env: { FOO: 'bar' } });

@nodejs/child_process Is this expected behavior that the second argument set in undefined or null prevents the third one from being transferred?

[borisovg]

@vsemozhetbyt thanks - this also works:

require('child_process').fork('./child.js', { env: { FOO: 'bar' } });

I can guess why this is happening, having seen enough dodgy JS code that does parameter overloading ;)

[shobhitchittora]

@vsemozhetbyt I think the check for arguments can be improved.

node/lib/child_process.js

Line 73 in 7f0f978

if (pos < arguments.length && arguments[pos] != null) {

node/lib/child_process.js

Line 74 in 7f0f978

if (typeof arguments[pos] !== 'object') {

We can check for emptiness (something like lodash.isEmpty) for both of the arguments. Then we can conditionally check whether both are present or not.

Or we can just document the behavior altogether. 😛

[ryzokuken]

This looks like an ambiguity problem, and improving docs seems to be the logical way forward to me as well.

[borisovg]

As a developer, even if documented, this looks like broken behaviour. Throwing an error on an invalid argument type is perfectly acceptable, but ignoring the subsequent argument is just shoddy - to be tolerated in a third party lib but not a core Node module. Just my opinion.

[ryzokuken]

@borisovg if you insist, I could look a tad deeper into this over the course of the next few days and hack up a small PR.