repl: add welcome message

[gengjiawen]

Motivation

I want to make node more friendly for new user. Actually it take me very long to find out node repl can load script :)

Also I am not quite sure I put the change in best location in repl.js.

Welcome message

The current welcome message is (copyed from windows powershell):

Welcome to Node.js v12.0.0-pre.
Type ".help" for more information.

Compare with other languages
In python (using docker run --rm -it python):

Python 3.7.2 (default, Jan 23 2019, 02:31:57) 
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.

In java (use docker run --rm -it openjdk:11):

Feb 05, 2019 2:42:25 PM java.util.prefs.FileSystemPreferences$1 run
INFO: Created user preferences directory.
|  Welcome to JShell -- Version 11.0.1
|  For an introduction type: /help intro

May need port to Node 8 && 10.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

[BridgeAR]

This is looking really good so far 👍 I just left a few nits that would be nice to be addressed as well.

[BridgeAR]

I have a slight preference for keeping the welcome message at the very top and to include preloaded output afterwards. But I am not sure if that's significantly more work or not. If it is, I am fine to keep it as is. We could still change it at some point.

[BridgeAR]

Seems like quite a few tests failed due to the recent changes. @gengjiawen would you be so kind and have another look?

[gengjiawen]

Looks like move the location cause 18 test case failed. I will try another fix.

[gengjiawen]

@jasnell @BridgeAR Can review this again ?

[ChALkeR]

@Trott perhaps this should be semver-major because it could potentially break some usecases that do not expect something like this?

@gengjiawen how would this behave when the output is piped (not a terminal)? Should piped output be excluded from the error message?

[targos]

@ChALkeR is it possible to pipe the built-in repl?

[ChALkeR]

@targos Yes, why not?

Each of those is interrupted by ^D after the console.log:

$ node > foo
console.log('bar')
$ cat foo
> bar
undefined
>

$ node | wc
console.log('foo')
       2       4      18

$ node | cat
> console.log('foo')
foo
undefined
>

$ node > /dev/stdout
> console.log('foo')
foo
undefined
>

The last one (redirected to /dev/stdout) has proper coloring for undefined, everything else has colors stripped.

[Trott]

@Trott perhaps this should be semver-major because it could potentially break some usecases that do not expect something like this?

@ChALkeR Sure. Following the "if there's any doubt, go with semver-major" guideline, I'll change it.

[Trott]

@Trott perhaps this should be semver-major because it could potentially break some usecases that do not expect something like this?

@nodejs/tsc

[gengjiawen]

@ChALkeR I am on windows, any command I can test ?

[joyeecheung]

LGTM with a suggestion. This is an excellent idea!

[gengjiawen]

@richardlau Can you retrigger Jenkins ci for this PR ? Thanks.

[richardlau]

@richardlau Can you retrigger Jenkins ci for this PR ? Thanks.

Tried, but Jenkins is a bit sick at the moment so nothing is executing: nodejs/build#1759

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/22420/

[gengjiawen]

@BridgeAR @richardlau @danbev Can we merge this PR since the CI is green.

[BridgeAR]

Landed in fe96314 🎉

There was a linter error due to a recent change that I fixed while landing.