Changing a null value to a mapping results in [object Object] string value.

[kevinswiber]

When changing a null value to an object, it gets sent to replacePrimitive, which turns it into the string [object Object].

yawn-yaml/src/index.js

Lines 224 to 232 in d870fbe

	if (newValue !== value && !isArray(valNode.value)) {
	// replace the value node
	yaml = replacePrimitive(valNode, newValue, yaml);
	// remove the key/value from newJson so it's not detected as new pair in
	// later code
	delete newJson[keyNode.value];
	}

[bubeck]

This is a test case showing the problem:

'use strict';

const YAWN      = require('yawn-yaml/cjs');

let str = `
  en-GB: ~
`;
let yawn = new YAWN(str);

let json = yawn.json;
json["en-GB"] = { key1: "test" };
yawn.json = json;

let str2 = yawn.yaml
console.log(str2);

// The output is
//  en-GB: [object Object]

// But I expect it to be
// en-GB:
//   key1: "test"