All files / lib/internal/readline emitKeypressEvents.js

94.94% Statements 94/99
88.88% Branches 16/18
100% Functions 4/4
94.94% Lines 94/99

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 1002x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 240x 240x 239x 239x 239x 239x 239x 239x 239x 239x 239x 239x 239x 817x 817x 817x 811x 811x 811x 811x 811x 811x 811x 811x 11059x 11059x 811x 811x 11059x 11059x 11059x 11059x 11059x 10x 10x 11059x 2x 2x 2x 2x 2x 2x 11059x 809x 817x         817x 239x 239x 478x 239x 239x 239x 478x 239x 240x   240x 239x 239x 240x 2x 2x  
'use strict';
 
const {
  SafeStringIterator,
  Symbol,
} = primordials;
 
const {
  charLengthAt,
  CSI,
  emitKeys,
} = require('internal/readline/utils');
const {
  kSawKeyPress,
} = require('internal/readline/interface');
 
const { clearTimeout, setTimeout } = require('timers');
const {
  kEscape,
} = CSI;
 
const { StringDecoder } = require('string_decoder');
 
const KEYPRESS_DECODER = Symbol('keypress-decoder');
const ESCAPE_DECODER = Symbol('escape-decoder');
 
// GNU readline library - keyseq-timeout is 500ms (default)
const ESCAPE_CODE_TIMEOUT = 500;
 
/**
 * accepts a readable Stream instance and makes it emit "keypress" events
 */
 
function emitKeypressEvents(stream, iface = {}) {
  if (stream[KEYPRESS_DECODER]) return;
 
  stream[KEYPRESS_DECODER] = new StringDecoder('utf8');
 
  stream[ESCAPE_DECODER] = emitKeys(stream);
  stream[ESCAPE_DECODER].next();
 
  const triggerEscape = () => stream[ESCAPE_DECODER].next('');
  const { escapeCodeTimeout = ESCAPE_CODE_TIMEOUT } = iface;
  let timeoutId;
 
  function onData(input) {
    if (stream.listenerCount('keypress') > 0) {
      const string = stream[KEYPRESS_DECODER].write(input);
      if (string) {
        clearTimeout(timeoutId);
 
        // This supports characters of length 2.
        iface[kSawKeyPress] = charLengthAt(string, 0) === string.length;
        iface.isCompletionEnabled = false;
 
        let length = 0;
        for (const character of new SafeStringIterator(string)) {
          length += character.length;
          if (length === string.length) {
            iface.isCompletionEnabled = true;
          }
 
          try {
            stream[ESCAPE_DECODER].next(character);
            // Escape letter at the tail position
            if (length === string.length && character === kEscape) {
              timeoutId = setTimeout(triggerEscape, escapeCodeTimeout);
            }
          } catch (err) {
            // If the generator throws (it could happen in the `keypress`
            // event), we need to restart it.
            stream[ESCAPE_DECODER] = emitKeys(stream);
            stream[ESCAPE_DECODER].next();
            throw err;
          }
        }
      }
    } else {
      // Nobody's watching anyway
      stream.removeListener('data', onData);
      stream.on('newListener', onNewListener);
    }
  }
 
  function onNewListener(event) {
    if (event === 'keypress') {
      stream.on('data', onData);
      stream.removeListener('newListener', onNewListener);
    }
  }
 
  if (stream.listenerCount('keypress') > 0) {
    stream.on('data', onData);
  } else {
    stream.on('newListener', onNewListener);
  }
}
 
module.exports = emitKeypressEvents;