tickets

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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 LONE \u surrogate escapes — hl's JSON.parse still
5. // refuses those; a valid pair parses since hybriel#15) 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. // SURROGATES (mission 036): a valid pair \ud83d\ude00 parses since hybriel#15; a LONE
56. // one (a high without a following \u low, or a low alone) still aborts hl's
57. // JSON.parse → refused here: 400, not 500.
58. if (u >= 55296 && u <= 56319) {
59. if (i + 6 >= s.length || s.charCodeAt(i + 5) != 92 || s.charCodeAt(i + 6) != 117) { return bad(i) }
60. let lo = hexAt(s, i + 7)
61. if (lo < 56320 || lo > 57343) { return bad(i) }
62. i = i + 6
63. } else if (u >= 56320 && u <= 57343) { return bad(i) }
64. i = i + 4
65. } else if (!(e == 34 || e == 92 || e == 47 || e == 98 || e == 102 || e == 110 || e == 114 || e == 116)) {
66. return bad(i)
67. }
68. }
69. i = i + 1
70. }
71. return bad(i)
72. }
74. static scanDigits = (s, at) => {
75. let i = at
76. let start = i
77. while (i < s.length && isDigit(s.charCodeAt(i))) { i = i + 1 }
78. return i == start ? bad(i) : i
79. }
81. static scanNumber = (s, at) => {
82. let i = at
83. if (s.charCodeAt(i) == 45) { i = i + 1 }
84. if (i >= s.length || !isDigit(s.charCodeAt(i))) { return bad(i) }
85. if (s.charCodeAt(i) == 48) { i = i + 1 } else { i = scanDigits(s, i) }
86. if (i < s.length && s.charCodeAt(i) == 46) {
87. i = scanDigits(s, i + 1)
88. if (i < 0) { return i }
89. }
90. if (i < s.length && (s.charCodeAt(i) == 101 || s.charCodeAt(i) == 69)) {
91. i = i + 1
92. if (i < s.length && (s.charCodeAt(i) == 43 || s.charCodeAt(i) == 45)) { i = i + 1 }
93. i = scanDigits(s, i)
94. }
95. return i
96. }
98. static scanWord = (s, i, word) => {
99. return s.slice(i, i + word.length) == word ? i + word.length : bad(i)
100. }
102. static scanValue = (s, at, depth) => {
103. let i = at
104. i = skipWs(s, i)
105. if (i >= s.length) { return bad(i) }
106. let c = s.charCodeAt(i)
107. if (c == 34) { return scanString(s, i) }
108. if (c == 45 || isDigit(c)) { return scanNumber(s, i) }
109. if (c == 116) { return scanWord(s, i, 'true') }
110. if (c == 102) { return scanWord(s, i, 'false') }
111. if (c == 110) { return scanWord(s, i, 'null') }
112. if (c == 123 || c == 91) {
113. if (depth >= maxDepth) { return bad(i) }
114. let close = c == 123 ? 125 : 93
115. i = skipWs(s, i + 1)
116. if (i < s.length && s.charCodeAt(i) == close) { return i + 1 }
117. while (true) {
118. if (c == 123) {
119. i = skipWs(s, i)
120. if (i >= s.length || s.charCodeAt(i) != 34) { return bad(i) }
121. i = scanString(s, i)
122. if (i < 0) { return i }
123. i = skipWs(s, i)
124. if (i >= s.length || s.charCodeAt(i) != 58) { return bad(i) }
125. i = i + 1
126. }
127. i = scanValue(s, i, depth + 1)
128. if (i < 0) { return i }
129. i = skipWs(s, i)
130. if (i >= s.length) { return bad(i) }
131. let d = s.charCodeAt(i)
132. if (d == close) { return i + 1 }
133. if (d != 44) { return bad(i) }
134. i = i + 1
135. }
136. }
137. return bad(i)
138. }
140. static jsonErrorAt = (text) => {
141. let i = scanValue(text, 0, 0)
142. if (i < 0) { return -i - 1 }
143. i = skipWs(text, i)
144. return i < text.length ? i : -1
145. }