repl: Proposal for better repl (implementation)

[princejwesley]

Checklist

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

Affected core subsystem(s)

repl

Description of change

• Welcome message with version and help guide
  • displayWelcomeMessage flag is used to
    turn on/off
• Differentiate execute & continue actions
  • ^M or enter key to execute the command
  • ^J to continue building multiline expression.
  • executeOnTimeout value is used to determine
    the end of expression when terminal is false.
• Pretty stack trace.
  • REPL specific stack frames are removed before
    emitting to output stream.
• Recoverable errors.
  • No more recoverable errors & no false positives.
• Defined commands(like .exit, .load)
  • Meaningful only at the top level.
  • .break is removed - no more get stuck
  • .clear is available only for local context

Welcome message template

$ node
Welcome to Node.js <<version>> (<<vm name>> VM, <<vm version>>)
Type ^M or enter to execute, ^J to continue, ^C to exit
Or try .help for help, more at https://nodejs.org/dist/<<version>>/docs/api/repl.html

>

Pretty stack trace

$ node -i
> throw new Error('tiny stack')
Error: tiny stack
    at repl:1:7
> var x y;
var x y;
      ^
SyntaxError: Unexpected identifier
>

Refs: #8195

~~~TODO~~~

• Rebase from master
• Fix flaky test cases
• Test in windows machine

[princejwesley]

CI: https://ci.nodejs.org/job/node-test-pull-request/4794/

CC: @nodejs/collaborators

[benjamingr]

The changes here are pretty extensive, are you sure you don't want to split this into several smaller PRs? It's pretty hard to review the different functionality changes this way.

I also think you probably want to elaborate on why magic mode was removed.

I'm generally +1 on the changes but I think this is significant enough to discuss in a CTC meeting.

[princejwesley]

@benjamingr 90% of the changes are adding/fixing tests. I don't know how to split it into smaller PRs. Magic mode has no effect and is discussed in #7850

[princejwesley]

@addaleax @Fishrock123 @thefourtheye Have a look!

[princejwesley]

Closing it. I'll create a new PR so that collaborators can have a look from recent list.