ident

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1. // jsoncheck.hl — WORKAROUND for hybriel ticket #12 (no soft JSON.parse): JSON.parse throws on
2. // invalid input and a Hybriel program cannot catch it, so the framework answers 500 with the
3. // source location. The API therefore checks the body's JSON SYNTAX by hand first (RFC 8259
4. // grammar, nesting depth capped at 64, NO \u surrogate escapes — hl's JSON.parse refuses
5. // them, even valid pairs) and answers 400. REMOVE this file and its one call in
6. // api.hl (readBody) once JSON.parse has a failure path (#12).
7. //
8. // jsonErrorAt(text) → -1 when `text` is one valid JSON value (surrounded by whitespace),
9. // else the 0-based character position of the first offence.
11. static maxDepth = 64
13. static isWs = (c) => { return c == 32 || c == 9 || c == 10 || c == 13 }
14. static isDigit = (c) => { return c >= 48 && c <= 57 }
15. static isHex = (c) => { return (c >= 48 && c <= 57) || (c >= 65 && c <= 70) || (c >= 97 && c <= 102) }
17. static hexValue = (c) => { return c <= 57 ? c - 48 : (c <= 70 ? c - 55 : c - 87) }
18. // the 4 hex digits at `at` as a number, or -1
19. static hexAt = (s, at) => {
20. if (at + 4 > s.length) { return -1 }
21. let v = 0
22. let k = 0
23. while (k < 4) {
24. let c = s.charCodeAt(at + k)
25. if (!isHex(c)) { return -1 }
26. v = v * 16 + hexValue(c)
27. k = k + 1
28. }
29. return v
30. }
32. static skipWs = (s, at) => {
33. let i = at
34. while (i < s.length && isWs(s.charCodeAt(i))) { i = i + 1 }
35. return i
36. }
38. // each scanner answers the position after what it read, or -(position + 1) of an offence
39. static bad = (i) => { return -(i + 1) }
41. static scanString = (s, at) => {
42. let i = at
43. i = i + 1
44. while (i < s.length) {
45. let c = s.charCodeAt(i)
46. if (c == 34) { return i + 1 }
47. if (c < 32) { return bad(i) }
48. if (c == 92) {
49. i = i + 1
50. if (i >= s.length) { return bad(i) }
51. let e = s.charCodeAt(i)
52. if (e == 117) {
53. let u = hexAt(s, i + 1)
54. if (u < 0) { return bad(i) }
55. // hl's JSON.parse refuses EVERY surrogate escape (\uD800-\uDFFF), even a valid
56. // pair like \ud83d\ude00 (hybriel issue, mission 004) — refuse it here: 400, not 500.
57. // Send such characters as raw UTF-8 instead (JS JSON.stringify does).
58. if (u >= 55296 && u <= 57343) { return bad(i) }
59. i = i + 4
60. } else if (!(e == 34 || e == 92 || e == 47 || e == 98 || e == 102 || e == 110 || e == 114 || e == 116)) {
61. return bad(i)
62. }
63. }
64. i = i + 1
65. }
66. return bad(i)
67. }
69. static scanDigits = (s, at) => {
70. let i = at
71. start = i
72. while (i < s.length && isDigit(s.charCodeAt(i))) { i = i + 1 }
73. return i == start ? bad(i) : i
74. }
76. static scanNumber = (s, at) => {
77. let i = at
78. if (s.charCodeAt(i) == 45) { i = i + 1 }
79. if (i >= s.length || !isDigit(s.charCodeAt(i))) { return bad(i) }
80. if (s.charCodeAt(i) == 48) { i = i + 1 } else { i = scanDigits(s, i) }
81. if (i < s.length && s.charCodeAt(i) == 46) {
82. i = scanDigits(s, i + 1)
83. if (i < 0) { return i }
84. }
85. if (i < s.length && (s.charCodeAt(i) == 101 || s.charCodeAt(i) == 69)) {
86. i = i + 1
87. if (i < s.length && (s.charCodeAt(i) == 43 || s.charCodeAt(i) == 45)) { i = i + 1 }
88. i = scanDigits(s, i)
89. }
90. return i
91. }
93. static scanWord = (s, i, word) => {
94. return s.slice(i, i + word.length) == word ? i + word.length : bad(i)
95. }
97. static scanValue = (s, at, depth) => {
98. let i = at
99. i = skipWs(s, i)
100. if (i >= s.length) { return bad(i) }
101. c = s.charCodeAt(i)
102. if (c == 34) { return scanString(s, i) }
103. if (c == 45 || isDigit(c)) { return scanNumber(s, i) }
104. if (c == 116) { return scanWord(s, i, 'true') }
105. if (c == 102) { return scanWord(s, i, 'false') }
106. if (c == 110) { return scanWord(s, i, 'null') }
107. if (c == 123 || c == 91) {
108. if (depth >= maxDepth) { return bad(i) }
109. close = c == 123 ? 125 : 93
110. i = skipWs(s, i + 1)
111. if (i < s.length && s.charCodeAt(i) == close) { return i + 1 }
112. while (true) {
113. if (c == 123) {
114. i = skipWs(s, i)
115. if (i >= s.length || s.charCodeAt(i) != 34) { return bad(i) }
116. i = scanString(s, i)
117. if (i < 0) { return i }
118. i = skipWs(s, i)
119. if (i >= s.length || s.charCodeAt(i) != 58) { return bad(i) }
120. i = i + 1
121. }
122. i = scanValue(s, i, depth + 1)
123. if (i < 0) { return i }
124. i = skipWs(s, i)
125. if (i >= s.length) { return bad(i) }
126. let d = s.charCodeAt(i)
127. if (d == close) { return i + 1 }
128. if (d != 44) { return bad(i) }
129. i = i + 1
130. }
131. }
132. return bad(i)
133. }
135. static jsonErrorAt = (text) => {
136. let i = scanValue(text, 0, 0)
137. if (i < 0) { return -i - 1 }
138. i = skipWs(text, i)
139. return i < text.length ? i : -1
140. }