BREAKING(jsonc): remove allowTrailingComma option (#5119)

jsonc/mod.ts

@@ -14,13 +14,7 @@
  * import { assertEquals } from "@std/assert/assert-equals";
  *
  * assertEquals(parse('{"foo": "bar", } // comment'), { foo: "bar" });
- *
  * assertEquals(parse('{"foo": "bar", } /* comment *\/'), { foo: "bar" });
- *
- * assertEquals(
- *   parse('{"foo": "bar" } // comment', { allowTrailingComma: false }),
- *   { foo: "bar" }
- * );
  * ```
  *
  * @module

jsonc/parse.ts

@@ -4,15 +4,6 @@
 import type { JsonValue } from "@std/json/types";
 export type { JsonValue } from "@std/json/types";
 
-/** Options for {@linkcode parse}. */
-export interface ParseOptions {
-  /** Allow trailing commas at the end of arrays and objects.
-   *
-   * @default {true}
-   */
-  allowTrailingComma?: boolean;
-}
-
 /**
  * Converts a JSON with Comments (JSONC) string into an object.
  *
@@ -24,7 +15,6 @@ export interface ParseOptions {
  * assertEquals(parse('{"foo": "bar"}'), { foo: "bar" });
  * assertEquals(parse('{"foo": "bar", }'), { foo: "bar" });
  * assertEquals(parse('{"foo": "bar", } /* comment *\/'), { foo: "bar" });
- * assertEquals(parse('{"foo": "bar" } // comment', { allowTrailingComma: false }), { foo: "bar" });
  * ```
  *
  * @throws {SyntaxError} If the JSONC string is invalid.
@@ -32,15 +22,11 @@ export interface ParseOptions {
  * @param options Options for parsing.
  * @returns The parsed JsonValue from the JSONC string.
  */
-export function parse(
+export function parse(text: string): JsonValue {
-  text: string,
-  options?: ParseOptions,
-): JsonValue {
-  const { allowTrailingComma = true } = { ...options };
   if (new.target) {
     throw new TypeError("parse is not a constructor");
   }
-  return new JSONCParser(text, { allowTrailingComma }).parse();
+  return new JSONCParser(text).parse();
 }
 
 type TokenType =
@@ -77,12 +63,10 @@ class JSONCParser {
   #text: string;
   #length: number;
   #tokenized: Generator<Token, void>;
-  #options: ParseOptions;
+  constructor(text: string) {
-  constructor(text: string, options: ParseOptions) {
     this.#text = `${text}`;
     this.#length = this.#text.length;
     this.#tokenized = this.#tokenize();
-    this.#options = options;
   }
   parse(): JsonValue {
     const token = this.#getNext();
@@ -238,12 +222,9 @@ class JSONCParser {
     //      │   │   │   │   │   │   ┌─────token3
     //      │   │   │   │   │   │   │   ┌─token4
     //  { "key" : value , "key" : value }
-    for (let isFirst = true;; isFirst = false) {
+    while (true) {
       const token1 = this.#getNext();
-      if (
+      if (token1.type === "EndObject") {
-        (isFirst || this.#options.allowTrailingComma) &&
-        token1.type === "EndObject"
-      ) {
         return target;
       }
       if (token1.type !== "String") {
@@ -290,12 +271,9 @@ class JSONCParser {
     //      │   │   ┌─────token1
     //      │   │   │   ┌─token2
     //  [ value , value ]
-    for (let isFirst = true;; isFirst = false) {
+    while (true) {
       const token1 = this.#getNext();
-      if (
+      if (token1.type === "EndArray") {
-        (isFirst || this.#options.allowTrailingComma) &&
-        token1.type === "EndArray"
-      ) {
         return target;
       }
       target.push(this.#parseJsonValue(token1));

jsonc/parse_test.ts

@@ -1,6 +1,6 @@
 // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
 
-import { parse, type ParseOptions } from "./parse.ts";
+import { parse } from "./parse.ts";
 import {
   assert,
   assertEquals,
@@ -14,12 +14,8 @@ import "./testdata/test262/test.ts";
 
 // The test code for the jsonc module can also be found in the testcode directory.
 
-function assertValidParse(
+function assertValidParse(text: string, expected: unknown) {
-  text: string,
+  assertEquals(parse(text), expected);
-  expected: unknown,
-  options?: ParseOptions,
-) {
-  assertEquals(parse(text, options), expected);
 }
 
 function assertInvalidParse(
@@ -27,10 +23,9 @@ function assertInvalidParse(
   // deno-lint-ignore no-explicit-any
   ErrorClass: new (...args: any[]) => Error,
   msgIncludes?: string,
-  options?: ParseOptions,
 ) {
   assertThrows(
-    () => parse(text, options),
+    () => parse(text),
     ErrorClass,
     msgIncludes,
   );
@@ -231,3 +226,7 @@ Deno.test({
     );
   },
 });
+
+Deno.test("parse() handles lone continuation byte in key and tailing comma", () => {
+  assertEquals(parse('{"<22>":"0",}'), { "<22>": "0" });
+});

jsonc/testdata/JSONTestSuite/test.ts

@@ -34,7 +34,7 @@ for await (
         JSON.parse(text);
       });
       const [hasJsoncError, jsoncError, jsoncResult] = getError(() => {
-        JSONC.parse(text, { allowTrailingComma: false });
+        JSONC.parse(text);
       });
 
       // If an error occurs in JSON.parse() but no error occurs in JSONC.parse(), or vice versa, an error is thrown.

jsonc/testdata/JSONTestSuite/test_parsing/n_object_lone_continuation_byte_in_key_and_trailing_comma.json

@@ -1 +0,0 @@
-{"ｹ":"0",}

jsonc/testdata/node-jsonc-parser/test.ts

@@ -11,19 +11,17 @@ import { assertEquals, assertThrows } from "../../../assert/mod.ts";
 function assertValidParse(
   text: string,
   expected: unknown,
-  options?: JSONC.ParseOptions,
 ) {
-  assertEquals(JSONC.parse(text, options), expected);
+  assertEquals(JSONC.parse(text), expected);
 }
 function assertInvalidParse(
   text: string,
   // deno-lint-ignore no-explicit-any
   ErrorClass: (new (...args: any[]) => Error),
   msgIncludes?: string,
-  options?: JSONC.ParseOptions,
 ) {
   assertThrows(
-    () => JSONC.parse(text, options),
+    () => JSONC.parse(text),
     ErrorClass,
     msgIncludes,
   );
@@ -83,9 +81,6 @@ Deno.test("[jsonc] parse node-jsonc-parser:arrays", () => {
 
 Deno.test("[jsonc] parse node-jsonc-parser:objects with errors", () => {
   assertInvalidParse("{,}", SyntaxError);
-  assertInvalidParse('{ "foo": true, }', SyntaxError, undefined, {
-    allowTrailingComma: false,
-  });
   assertInvalidParse('{ "bar": 8 "xoo": "foo" }', SyntaxError);
   assertInvalidParse('{ ,"bar": 8 }', SyntaxError);
   assertInvalidParse('{ ,"bar": 8, "foo" }', SyntaxError);
@@ -119,13 +114,4 @@ Deno.test("[jsonc] parse node-jsonc-parser:trailing comma", () => {
   );
   assertValidParse("[ 1, 2, ]", [1, 2]);
   assertValidParse("[ 1, 2 ]", [1, 2]);
-
-  assertInvalidParse('{ "hello": [], }', SyntaxError, undefined, options);
-  assertInvalidParse(
-    '{ "hello": [], "world": {}, }',
-    SyntaxError,
-    undefined,
-    options,
-  );
-  assertInvalidParse("[ 1, 2, ]", SyntaxError, undefined, options);
 });