Literal block style multilines don't survive round trip; can it be forced?

When using literal multiline block strings inside my YAML file, converting to JS, and then back, sometimes the multiline literal block survives, but not always.

Is there a way to force a particular behavior? Having them be literal block strings inside the YAML is, IMHO, definitely more readable and editable by humans.

An example program:

const yaml = require('js-yaml')

const bad = `
abc:
  - name: xxx
    sample: |
      {
          "abc": 2,
          "def" : {
          "efg" : {
      	"ok" : 6666,
      	"nope" : "./yyy",

`.trim() // make sure the whitespace is not the difference

const good = `
abc:
  - name: xxx
    sample: |
      {
          "abc": 2,
          "def" : {
`.trim() // make sure the whitespace is not the difference

const badDoc = yaml.safeLoad(bad)
const goodDoc = yaml.safeLoad(good)

const goodDumped = yaml.safeDump(goodDoc)
if( goodDumped === good ) {
    console.log( "Round trip was good for GOOD file\n" )
}

const badDumped = yaml.safeDump(badDoc).trim()
if( badDumped !== bad ) {
    console.log( "Round trip was bad for BAD file" )
    console.log( "INPUT: ", bad, "\n\n" )
    console.log( "OUTPUT: ", badDumped,"\n\n" )
}
else {
    console.log( badDumped, bad )
}

The output of this is:

Round trip was good for GOOD file

Round trip was bad for BAD file
INPUT:  abc:
  - name: xxx
    sample: |
      {
          "abc": 2,
          "def" : {
          "efg" : {
      	"ok" : 6666,
      	"nope" : "./yyy", 


OUTPUT:  abc:
  - name: xxx
    sample: "{\n    \"abc\": 2,\n    \"def\" : {\n    \"efg\" : {\n\t\"ok\" : 6666,\n\t\"nope\" : \"./yyy\",\n" 

Note that sample has been turned into a string with newlines encoded, rather than a literal multiline block.

It seems strange that the shorter version (good) does preserve literal block style, but the longer one does not. Am I missing something subtle about using the library?

(IMHO, it would seem more usable to have shorter strings drop the literal multiline block, while longer ones always use the | format, but the library works the opposite way.)

I would really like a way to always have multiline values (any strings with newlines) to be output as literal multiline block strings so that I have the option to edit them by hand easily.

I’m using version "js-yaml": "^3.12.1"

[RockyYan1994]

Seems like is pass lineWidth to be -1 will set block style to be STYLE_LITERAL https://github.com/nodeca/js-yaml/blob/d6983dd4291849b2854e8d26e1beb302edfd4c76/lib/js-yaml/dumper.js#L274

[booninite]

// Also prefer folding a super-long line.

This comment does not make functional sense. Anyone using this library to generate YAML containing multi-line blocks with white space sensitive content that goes over an arbitrary line length will get caught on this (which is increasingly common given the pattern of inlining resources in Kubernetes objects such as ConfigMaps). I think it makes more sense for the code to attempt to honor the contents of the string, which would essentially always be |.