doc: are `os.uptime()` returned type and remark correct?

[vsemozhetbyt]

• Version: 8.0.0-rc.0
• Platform: Windows 7 x64
• Subsystem: doc, os

Currently, both os.uptime() and process.uptime() return number with fractional seconds on Windows:

> os.uptime()
34298.2171316
> process.uptime()
20.648

However, their docs are different here:

https://github.com/nodejs/node/blame/7a5d07c7fbd43f3645d7f707fd6a98f2a251bdbd/doc/api/os.md#L372-L384

https://github.com/nodejs/node/blame/47f8f7462fb198aa27ede602c43786bdbfda37a2/doc/api/process.md#L1662-L1671

Are os.uptime() returned type integer and *Note* outdated or just OS-dependent?

[gibfahn]

Output on macOS (Sierra):

> os.uptime()
245758
> process.uptime()
281.972

Output on Ubuntu 16.04:

> os.uptime()
174
> process.uptime()
9.451

[vsemozhetbyt]

So it seems this is wrong only for Windows. What should be fixed — doc or Windows implementation?

[vsemozhetbyt]

If Windows implementation should be fixed, is it worth to land it in 8.0 as this is semver-major (despite of the doc though)?

cc @nodejs/platform-windows

[bnoordhuis]

The documentation is wrong-ish. uv_uptime() returns (in an out param) a double but the UNIX implementations of that function don't currently bother to mix in the sub-second fraction. That could change in the future though, if someone requests it.

[vsemozhetbyt]

So the doc should describe OS-dependent behavior here? If so, can anybody edit it, as I am not good at writing long English text properly? Or I can open a PR with a proposed wording.

[bnoordhuis]

How about this?

Note: the return value includes fractions of a second on some platforms. Use Math.floor() to get whole seconds.

Feel free to steal and PR.

[gibfahn]

Maybe worth changing on some platforms to on Windows if it's Windows specific.

[vsemozhetbyt]

I've combined two propositions in #12294