1#![cfg_attr(not(feature = "std"), no_std)]
43#![forbid(unsafe_code)]
44#![warn(missing_docs)]
45
46extern crate alloc;
47
48#[cfg(feature = "canonical")]
49mod canonical;
50mod error;
51mod limits;
52mod number;
53mod parse;
54mod value;
55mod write;
56
57#[cfg(feature = "canonical")]
58pub use canonical::{to_canonical_string, to_canonical_vec};
59pub use error::{
60 JsonError, JsonErrorKind, JsonLimitKind, JsonNumberError, JsonPath, JsonPathSegment,
61};
62pub use limits::JsonLimits;
63pub use number::JsonNumber;
64pub use parse::{parse, parse_str, parse_with_limits};
65pub use value::{JsonMember, JsonObject, JsonValue};
66pub use write::{to_compact_string, to_compact_vec};
67
68#[cfg(test)]
69mod tests {
70 use super::*;
71 use alloc::string::{String, ToString};
72
73 fn parse_ok(input: &str) -> JsonValue {
74 parse_str(input).expect("should parse")
75 }
76
77 fn kind(input: &str) -> JsonErrorKind {
78 parse_str(input).expect_err("should fail").kind().clone()
79 }
80
81 #[test]
84 fn parses_scalars() {
85 assert_eq!(parse_ok("null"), JsonValue::Null);
86 assert_eq!(parse_ok("true"), JsonValue::Bool(true));
87 assert_eq!(parse_ok("false"), JsonValue::Bool(false));
88 assert_eq!(parse_ok("\"hi\"").as_str(), Some("hi"));
89 assert_eq!(parse_ok("42").as_number().unwrap().to_i64().unwrap(), 42);
90 }
91
92 #[test]
93 fn whitespace_is_allowed_around_values() {
94 assert_eq!(parse_ok(" \t\r\n 7 \n").as_number().unwrap().as_str(), "7");
95 }
96
97 #[test]
98 fn only_json_whitespace_is_accepted() {
99 assert_eq!(kind("\u{0B}1"), JsonErrorKind::UnexpectedByte);
101 }
102
103 #[test]
106 fn parses_object_and_array() {
107 let value = parse_ok(r#"{"a":[1,2,3],"b":{"c":null}}"#);
108 let obj = value.as_object().unwrap();
109 assert_eq!(obj.len(), 2);
110 assert_eq!(obj.get("a").unwrap().as_array().unwrap().len(), 3);
111 assert!(obj
112 .get("b")
113 .unwrap()
114 .as_object()
115 .unwrap()
116 .get("c")
117 .unwrap()
118 .is_null());
119 }
120
121 #[test]
122 fn empty_containers() {
123 assert_eq!(parse_ok("[]").as_array().unwrap().len(), 0);
124 assert_eq!(parse_ok("{}").as_object().unwrap().len(), 0);
125 }
126
127 #[test]
130 fn rejects_trailing_data() {
131 assert_eq!(kind("1 2"), JsonErrorKind::TrailingData);
132 assert_eq!(kind("{} x"), JsonErrorKind::TrailingData);
133 }
134
135 #[test]
136 fn rejects_comments_and_trailing_commas() {
137 assert_eq!(kind("1 // c"), JsonErrorKind::TrailingData);
138 assert_eq!(kind("[1,]"), JsonErrorKind::UnexpectedByte);
139 assert_eq!(kind(r#"{"a":1,}"#), JsonErrorKind::UnexpectedByte);
140 }
141
142 #[test]
143 fn rejects_bad_numbers() {
144 for bad in ["01", "1.", "-", "1e", "1e+", "00", "1.2.3"] {
145 assert_eq!(kind(bad), JsonErrorKind::InvalidNumber, "input {bad:?}");
146 }
147 assert_eq!(kind(".5"), JsonErrorKind::UnexpectedByte);
150 assert_eq!(kind("+1"), JsonErrorKind::UnexpectedByte);
151 assert_eq!(kind("0x1"), JsonErrorKind::TrailingData);
152 }
153
154 #[test]
155 fn rejects_nan_and_infinity() {
156 assert_eq!(kind("NaN"), JsonErrorKind::UnexpectedByte);
157 assert_eq!(kind("Infinity"), JsonErrorKind::UnexpectedByte);
158 assert_eq!(kind("-Infinity"), JsonErrorKind::InvalidNumber);
159 }
160
161 #[test]
162 fn rejects_unescaped_control_and_bad_escapes() {
163 assert_eq!(kind("\"\u{01}\""), JsonErrorKind::UnescapedControlCharacter);
164 assert_eq!(kind(r#""\x""#), JsonErrorKind::InvalidEscape);
165 assert_eq!(kind(r#""\u00""#), JsonErrorKind::InvalidUnicodeEscape);
166 }
167
168 #[test]
169 fn rejects_lone_surrogates() {
170 assert_eq!(kind(r#""\uD800""#), JsonErrorKind::LoneSurrogate);
171 assert_eq!(kind(r#""\uDC00""#), JsonErrorKind::LoneSurrogate);
172 assert_eq!(kind(r#""\uD800a""#), JsonErrorKind::LoneSurrogate);
173 }
174
175 #[test]
176 fn accepts_valid_surrogate_pair() {
177 assert_eq!(parse_ok(r#""𝄞""#).as_str(), Some("\u{1D11E}"));
178 }
179
180 #[test]
181 fn rejects_invalid_utf8_and_bom() {
182 assert_eq!(
183 parse(&[0xff]).unwrap_err().kind().clone(),
184 JsonErrorKind::InvalidUtf8
185 );
186 assert_eq!(
187 parse(&[0xEF, 0xBB, 0xBF, b'1']).unwrap_err().kind().clone(),
188 JsonErrorKind::InvalidUtf8
189 );
190 }
191
192 #[test]
195 fn escape_and_literal_decode_equally() {
196 assert_eq!(parse_ok(r#""a""#), parse_ok(r#""a""#));
197 }
198
199 #[test]
200 fn decodes_named_escapes() {
201 assert_eq!(
202 parse_ok(r#""\n\t\r\b\f\"\\\/""#).as_str(),
203 Some("\n\t\r\u{08}\u{0C}\"\\/")
204 );
205 }
206
207 #[test]
210 fn rejects_duplicate_keys() {
211 assert_eq!(kind(r#"{"a":1,"a":2}"#), JsonErrorKind::DuplicateKey);
212 }
213
214 #[test]
215 fn duplicate_detection_is_after_escape_decoding() {
216 assert_eq!(
217 kind(r#"{"role":"user","role":"admin"}"#),
218 JsonErrorKind::DuplicateKey
219 );
220 }
221
222 #[test]
225 fn enforces_depth_limit() {
226 let limits = JsonLimits::new().with_max_depth(3);
227 assert!(parse_with_limits(b"[[[1]]]", limits).is_ok());
228 assert_eq!(
229 parse_with_limits(b"[[[[1]]]]", limits)
230 .unwrap_err()
231 .kind()
232 .clone(),
233 JsonErrorKind::LimitExceeded(JsonLimitKind::Depth)
234 );
235 }
236
237 #[test]
238 fn enforces_count_limits() {
239 let limits = JsonLimits::new();
240 let limits = JsonLimits {
241 max_array_items: 2,
242 max_object_members: 2,
243 max_total_nodes: 100,
244 ..limits
245 };
246 assert_eq!(
247 parse_with_limits(b"[1,2,3]", limits)
248 .unwrap_err()
249 .kind()
250 .clone(),
251 JsonErrorKind::LimitExceeded(JsonLimitKind::ArrayItems)
252 );
253 assert_eq!(
254 parse_with_limits(br#"{"a":1,"b":2,"c":3}"#, limits)
255 .unwrap_err()
256 .kind()
257 .clone(),
258 JsonErrorKind::LimitExceeded(JsonLimitKind::ObjectMembers)
259 );
260 }
261
262 #[test]
263 fn enforces_total_nodes_and_input_bytes() {
264 let nodes = JsonLimits::new().with_max_total_nodes(2);
265 assert_eq!(
266 parse_with_limits(b"[1,2]", nodes)
267 .unwrap_err()
268 .kind()
269 .clone(),
270 JsonErrorKind::LimitExceeded(JsonLimitKind::TotalNodes)
271 );
272 let bytes = JsonLimits::new().with_max_input_bytes(2);
273 assert_eq!(
274 parse_with_limits(b"[1]", bytes).unwrap_err().kind().clone(),
275 JsonErrorKind::LimitExceeded(JsonLimitKind::InputBytes)
276 );
277 }
278
279 #[test]
280 fn enforces_string_and_number_byte_limits() {
281 let s = JsonLimits {
282 max_string_bytes: 3,
283 ..JsonLimits::new()
284 };
285 assert_eq!(
286 parse_with_limits(br#""abcd""#, s)
287 .unwrap_err()
288 .kind()
289 .clone(),
290 JsonErrorKind::LimitExceeded(JsonLimitKind::StringBytes)
291 );
292 let n = JsonLimits {
293 max_number_bytes: 2,
294 ..JsonLimits::new()
295 };
296 assert_eq!(
297 parse_with_limits(b"12345", n).unwrap_err().kind().clone(),
298 JsonErrorKind::LimitExceeded(JsonLimitKind::NumberBytes)
299 );
300 }
301
302 #[test]
305 fn number_conversions() {
306 assert_eq!(parse_ok("-7").as_number().unwrap().to_i64().unwrap(), -7);
307 assert_eq!(parse_ok("7").as_number().unwrap().to_u64().unwrap(), 7);
308 assert!((parse_ok("1.5").as_number().unwrap().to_f64().unwrap() - 1.5).abs() < 1e-12);
309 assert_eq!(
310 parse_ok("1.5").as_number().unwrap().to_i64(),
311 Err(JsonNumberError::NotAnInteger)
312 );
313 assert_eq!(
314 parse_ok("99999999999999999999999")
315 .as_number()
316 .unwrap()
317 .to_i64(),
318 Err(JsonNumberError::OutOfRange)
319 );
320 assert_eq!(
321 parse_ok("1e400").as_number().unwrap().to_f64(),
322 Err(JsonNumberError::NotFinite)
323 );
324 }
325
326 #[test]
327 fn number_preserves_representation() {
328 assert_eq!(parse_ok("1.0").as_number().unwrap().as_str(), "1.0");
329 assert_ne!(parse_ok("1.0"), parse_ok("1")); }
331
332 #[test]
333 fn json_number_from_f64() {
334 assert_eq!(JsonNumber::try_from_f64(1.5).unwrap().as_str(), "1.5");
335 assert_eq!(
336 JsonNumber::try_from_f64(f64::NAN),
337 Err(JsonNumberError::NotFinite)
338 );
339 assert_eq!(
340 JsonNumber::try_from_f64(f64::INFINITY),
341 Err(JsonNumberError::NotFinite)
342 );
343 assert_eq!(JsonNumber::new("01"), Err(JsonNumberError::InvalidNumber));
344 }
345
346 #[test]
349 fn error_reports_location_and_path() {
350 let err = parse_str(" @").unwrap_err();
351 assert_eq!(err.kind().clone(), JsonErrorKind::UnexpectedByte);
352 assert_eq!(err.offset(), 2);
353 assert_eq!(err.line(), 1);
354 assert_eq!(err.column(), 3);
355
356 let err = parse_str(r#"{"users":[{"name":1},{"name":}]}"#).unwrap_err();
357 let path = err.path().unwrap().to_string();
358 assert_eq!(path, "$.users[1].name");
359 }
360
361 #[test]
364 fn compact_roundtrip_and_golden_bytes() {
365 let value = parse_ok(r#"{"a":1,"b":true,"c":[null,"x"]}"#);
366 assert_eq!(
367 to_compact_vec(&value),
368 br#"{"a":1,"b":true,"c":[null,"x"]}"#
369 );
370 let again = parse_str(&to_compact_string(&value)).unwrap();
372 assert_eq!(value, again);
373 }
374
375 #[test]
376 fn writer_escapes_control_and_special_characters() {
377 let mut object = JsonObject::new();
378 object.insert(
379 String::from("k"),
380 JsonValue::String(String::from("a\nb\"c\\\u{01}")),
381 );
382 let value = JsonValue::Object(object);
383 assert_eq!(to_compact_string(&value), r#"{"k":"a\nb\"c\\\u0001"}"#);
384 }
385
386 #[test]
387 fn object_insert_replaces_in_place() {
388 let mut object = JsonObject::new();
389 assert!(object
390 .insert(String::from("a"), JsonValue::Bool(true))
391 .is_none());
392 let old = object.insert(String::from("a"), JsonValue::Bool(false));
393 assert_eq!(old, Some(JsonValue::Bool(true)));
394 assert_eq!(object.len(), 1);
395 }
396
397 #[test]
398 fn deeply_nested_within_limits_does_not_overflow() {
399 let depth = 64;
401 let mut s = String::new();
402 for _ in 0..depth {
403 s.push('[');
404 }
405 s.push('1');
406 for _ in 0..depth {
407 s.push(']');
408 }
409 let _ = parse_str(&s); assert!(parse_with_limits(s.as_bytes(), JsonLimits::new().with_max_depth(64)).is_ok());
412 }
413
414 #[test]
415 fn arbitrary_bytes_never_panic() {
416 for input in [
418 &b""[..],
419 b" ",
420 b"{",
421 b"[",
422 b"\"",
423 b"\"\\",
424 b"\"\\u",
425 b"tru",
426 b"-",
427 b"[,]",
428 b"{,}",
429 b"\xff\xfe",
430 b"[[[",
431 b"}}}",
432 b"\"\\uD800\"",
433 b"1e",
434 b"{\"a\"}",
435 ] {
436 let _ = parse(input);
437 }
438 }
439
440 #[test]
441 fn value_accessors_return_inner_or_none() {
442 let v = parse_ok(r#"{"b":true,"n":7,"s":"x","a":[1],"nil":null}"#);
443 let o = v.as_object().expect("object");
444 assert!(o.get("nil").unwrap().is_null());
445 assert_eq!(o.get("b").unwrap().as_bool(), Some(true));
446 assert_eq!(o.get("s").unwrap().as_str(), Some("x"));
447 assert_eq!(o.get("n").unwrap().as_number().unwrap().as_str(), "7");
448 assert_eq!(o.get("a").unwrap().as_array().unwrap().len(), 1);
449
450 let b = JsonValue::Bool(true);
452 assert!(!b.is_null());
453 assert_eq!(b.as_str(), None);
454 assert_eq!(b.as_number(), None);
455 assert_eq!(b.as_array(), None);
456 assert!(b.as_object().is_none());
457 assert_eq!(JsonValue::Null.as_bool(), None);
458 }
459
460 #[test]
461 fn object_insert_get_iter_and_len() {
462 let mut obj = JsonObject::new();
463 assert!(obj.is_empty());
464 assert_eq!(obj.len(), 0);
465 assert!(!obj.contains_key("k"));
466
467 assert_eq!(obj.insert("k".to_string(), JsonValue::Bool(false)), None);
468 assert!(obj.contains_key("k"));
469 assert_eq!(obj.len(), 1);
470
471 let old = obj.insert("k".to_string(), JsonValue::Bool(true));
473 assert_eq!(old, Some(JsonValue::Bool(false)));
474 assert_eq!(obj.len(), 1);
475 assert_eq!(obj.get("k"), Some(&JsonValue::Bool(true)));
476 assert_eq!(obj.get("missing"), None);
477
478 obj.insert("k2".to_string(), JsonValue::Null);
479 let members: Vec<&str> = obj.iter().map(|m| m.key()).collect();
480 assert_eq!(members, ["k", "k2"]);
481 assert_eq!(obj.iter().next().unwrap().value(), &JsonValue::Bool(true));
482
483 assert_eq!(JsonObject::default().len(), 0);
484 }
485
486 #[test]
487 fn number_conversions_cover_each_error() {
488 let int = JsonNumber::new("42").unwrap();
489 assert!(int.is_integer());
490 assert_eq!(int.to_i64(), Ok(42));
491 assert_eq!(int.to_u64(), Ok(42));
492 assert_eq!(int.to_f64(), Ok(42.0));
493
494 let neg = JsonNumber::new("-1").unwrap();
495 assert_eq!(neg.to_u64(), Err(JsonNumberError::OutOfRange));
496
497 let frac = JsonNumber::new("1.5").unwrap();
498 assert!(!frac.is_integer());
499 assert_eq!(frac.to_i64(), Err(JsonNumberError::NotAnInteger));
500 assert_eq!(frac.to_u64(), Err(JsonNumberError::NotAnInteger));
501 assert_eq!(frac.to_f64(), Ok(1.5));
502
503 let huge = JsonNumber::new("99999999999999999999").unwrap();
504 assert_eq!(huge.to_i64(), Err(JsonNumberError::OutOfRange));
505
506 let overflow = JsonNumber::new("1e400").unwrap();
507 assert_eq!(overflow.to_f64(), Err(JsonNumberError::NotFinite));
508
509 assert_eq!(JsonNumber::new("+1"), Err(JsonNumberError::InvalidNumber));
510 assert_eq!(JsonNumber::try_from_f64(2.5).unwrap().to_f64(), Ok(2.5));
511 assert_eq!(
512 JsonNumber::try_from_f64(f64::NAN),
513 Err(JsonNumberError::NotFinite)
514 );
515 assert_eq!(
516 JsonNumber::try_from_f64(f64::INFINITY),
517 Err(JsonNumberError::NotFinite)
518 );
519 }
520
521 #[test]
522 fn limits_profiles_and_builders() {
523 assert_eq!(JsonLimits::default(), JsonLimits::new());
524 assert!(JsonLimits::conservative().max_input_bytes < JsonLimits::new().max_input_bytes);
525 assert!(JsonLimits::permissive().max_input_bytes > JsonLimits::new().max_input_bytes);
526
527 let tuned = JsonLimits::new()
528 .with_max_depth(8)
529 .with_max_input_bytes(1024)
530 .with_max_string_bytes(16)
531 .with_max_total_nodes(32);
532 assert_eq!(tuned.max_depth, 8);
533 assert_eq!(tuned.max_input_bytes, 1024);
534 assert_eq!(tuned.max_string_bytes, 16);
535 assert_eq!(tuned.max_total_nodes, 32);
536 }
537
538 #[test]
539 fn error_display_covers_each_kind() {
540 let cases: &[(&str, &str)] = &[
542 ("", "unexpected end of input"),
543 ("@", "unexpected byte"),
544 ("\"a\\xb\"", "invalid escape sequence"),
545 ("\"\\uZZZZ\"", "invalid unicode escape"),
546 ("\"\\uD800\"", "unpaired UTF-16 surrogate"),
547 ("01", "invalid number"),
548 ("{\"a\":1,\"a\":2}", "duplicate object key"),
549 ("true false", "trailing data after JSON value"),
550 ];
551 for (input, expected) in cases {
552 let err = parse_str(input).unwrap_err();
553 assert!(
554 err.to_string().contains(expected),
555 "input {input:?} -> {err} (expected to contain {expected:?})"
556 );
557 }
558
559 let ctrl = parse(b"\"\x01\"").unwrap_err();
561 assert!(ctrl.to_string().contains("unescaped control character"));
562
563 let utf8 = parse(b"\xff").unwrap_err();
565 assert!(utf8.to_string().contains("invalid UTF-8"));
566 }
567
568 #[test]
569 fn error_accessors_and_limit_display_with_path() {
570 let limits = JsonLimits::new().with_max_depth(1);
571 let err = parse_with_limits(b"[[1]]", limits).unwrap_err();
572 assert_eq!(
573 err.kind(),
574 &JsonErrorKind::LimitExceeded(JsonLimitKind::Depth)
575 );
576 assert!(err.offset() >= 1);
577 assert_eq!(err.line(), 1);
578 assert!(err.column() >= 1);
579 let shown = err.to_string();
580 assert!(shown.contains("limit exceeded: nesting depth"));
581 assert!(shown.contains("path: $"));
582 assert_eq!(JsonLimitKind::Depth.as_str(), "nesting depth");
583 }
584
585 #[test]
586 fn path_display_formats_keys_and_indices() {
587 let path = JsonPath::from_segments(vec![
588 JsonPathSegment::Key("users".to_string()),
589 JsonPathSegment::Index(3),
590 JsonPathSegment::Key("email".to_string()),
591 ]);
592 assert_eq!(path.to_string(), "$.users[3].email");
593 assert_eq!(path.segments().len(), 3);
594 assert_eq!(JsonPath::default().to_string(), "$");
595 }
596
597 #[test]
598 fn number_error_display_is_distinct() {
599 assert_eq!(
600 JsonNumberError::OutOfRange.to_string(),
601 "number out of range for target type"
602 );
603 assert_eq!(
604 JsonNumberError::NotAnInteger.to_string(),
605 "number is not an integer"
606 );
607 assert_eq!(
608 JsonNumberError::NotFinite.to_string(),
609 "number is not finite"
610 );
611 assert_eq!(
612 JsonNumberError::InvalidNumber.to_string(),
613 "not a valid JSON number"
614 );
615 }
616
617 #[test]
618 fn writer_serializes_all_branches() {
619 let mut obj = JsonObject::new();
620 obj.insert("off".to_string(), JsonValue::Bool(false));
621 obj.insert(
622 "esc".to_string(),
623 JsonValue::String("\u{08}\u{0C}\n\r\t\u{1F}".to_string()),
625 );
626 obj.insert(
627 "arr".to_string(),
628 JsonValue::Array(vec![JsonValue::Null, JsonValue::Bool(true)]),
629 );
630 let value = JsonValue::Object(obj);
631
632 let s = to_compact_string(&value);
633 assert_eq!(parse_str(&s).unwrap(), value);
636 assert_eq!(to_compact_vec(&value), s.clone().into_bytes());
637 assert!(s.starts_with("{\"off\":false,"));
638 assert!(s.ends_with(",\"arr\":[null,true]}"));
639 }
640
641 #[cfg(feature = "std")]
642 #[test]
643 fn errors_implement_std_error() {
644 fn assert_error<E: std::error::Error>(_: &E) {}
645 let parse_err = parse_str("").unwrap_err();
646 assert_error(&parse_err);
647 let num_err = JsonNumber::new("1.5").unwrap().to_i64().unwrap_err();
648 assert_error(&num_err);
649 }
650}