fix(whitespace): maintain trailing whitespace after json payload in r…

…esult

lib/document/document.ts

@@ -21,6 +21,7 @@ export class JsonDocument
 		private json: string,
 		public root: JsonNodeType,
 		private rootIndentation: Indentable,
+		private trailingIndentation: string,
 		options?: Partial< JsonDocumentOptions >
 	)
 	{
@@ -135,7 +136,9 @@ export class JsonDocument
 				throw new Error( `Unexpected node type` );
 		};
 
-		return rootIndent + stringify( this.root, rootIndent );
+		return rootIndent
+			+ stringify( this.root, rootIndent )
+			+ this.trailingIndentation;
 	}
 
 	toJSON( ): string
@@ -177,6 +180,7 @@ export function parseJson( json: string, options?: JsonDocumentOptions )
 		json,
 		parsed.root,
 		parsed.initialIndentation,
+		parsed.trailingWhitespace,
 		{
 			whitespace: 'auto',
 			...options,

lib/document/parse-to-nodes.ts

@@ -20,22 +20,29 @@ import { JsonValueBase } from './types-internal.js'
 export interface ParseResult
 {
 	initialIndentation: Indentable;
+	trailingWhitespace: string;
 	root: JsonNodeType;
 }
 
 export function parse( json: string ): ParseResult
 {
-	const tokens = lexer( json );
+	const tokens = lexer( json ) as LexerTokens;
 
 	const { whitespace: initialWhitespace, consumedTokens: pos } =
 		extractWhitespace( tokens, 0 );
 
 	const initialIndentation = initialWhitespace.indentable;
-	const root = makeJsonAny( tokens, pos ).value;
+	const { value: root, consumedTokens } = makeJsonAny( tokens, pos );
+
+	const trailingPos = pos + consumedTokens;
+	const trailingWhitespace =
+		tokens[ trailingPos ]?.type === 'whitespace'
+		? tokens[ trailingPos ]!.raw
+		: '';
 
 	makeRelativeIndentations( root );
 
-	return { initialIndentation, root };
+	return { initialIndentation, trailingWhitespace, root };
 }
 
 function makeRelativeIndentations( node: JsonNodeType )

lib/rfc6902.test.ts

@@ -4,6 +4,16 @@ import type { Operation } from './types-rfc6902.js'
 
 describe( 'rfc6902', ( ) =>
 {
+	it( 'maintains trailing whitespace', ( ) =>
+	{
+		const before = `{\n  "foo": "bar"\n}\n\n\t  \n`;
+		const after = `{\n  "foo": "bar"\n}\n\n\t  \n`;
+
+		const res = jsonPatch( before, [ ] );
+
+		expect( res ).toBe( after );
+	} );
+
 	describe( 'add', ( ) =>
 	{
 		it( 'object add ordered (after)', ( ) =>