libweb/src/parse.ts

377 lines
10 KiB
TypeScript

// @ts-nocheck
import { objAsString } from "./objAsString.js";
import { Err } from "./types.js";
// json_parse extracted from the json-bigint npm library
// regexpxs extracted from
// (c) BSD-3-Clause
// https://github.com/fastify/secure-json-parse/graphs/contributors and https://github.com/hapijs/bourne/graphs/contributors
const suspectProtoRx =
/(?:_|\\u005[Ff])(?:_|\\u005[Ff])(?:p|\\u0070)(?:r|\\u0072)(?:o|\\u006[Ff])(?:t|\\u0074)(?:o|\\u006[Ff])(?:_|\\u005[Ff])(?:_|\\u005[Ff])/;
const suspectConstructorRx =
/(?:c|\\u0063)(?:o|\\u006[Ff])(?:n|\\u006[Ee])(?:s|\\u0073)(?:t|\\u0074)(?:r|\\u0072)(?:u|\\u0075)(?:c|\\u0063)(?:t|\\u0074)(?:o|\\u006[Ff])(?:r|\\u0072)/;
let json_parse = function (options) {
"use strict";
// This is a function that can parse a JSON text, producing a JavaScript
// data structure. It is a simple, recursive descent parser. It does not use
// eval or regular expressions, so it can be used as a model for implementing
// a JSON parser in other languages.
// We are defining the function inside of another function to avoid creating
// global variables.
// Default options one can override by passing options to the parse()
let _options = {
strict: false, // not being strict means do not generate syntax errors for "duplicate key"
storeAsString: false, // toggles whether the values should be stored as BigNumber (default) or a string
alwaysParseAsBig: false, // toggles whether all numbers should be Big
protoAction: "error",
constructorAction: "error",
};
// If there are options, then use them to override the default _options
if (options !== undefined && options !== null) {
if (options.strict === true) {
_options.strict = true;
}
if (options.storeAsString === true) {
_options.storeAsString = true;
}
_options.alwaysParseAsBig = options.alwaysParseAsBig === true ? options.alwaysParseAsBig : false;
if (typeof options.constructorAction !== "undefined") {
if (
options.constructorAction === "error" ||
options.constructorAction === "ignore" ||
options.constructorAction === "preserve"
) {
_options.constructorAction = options.constructorAction;
} else {
throw new Error(
`Incorrect value for constructorAction option, must be "error", "ignore" or undefined but passed ${options.constructorAction}`
);
}
}
if (typeof options.protoAction !== "undefined") {
if (options.protoAction === "error" || options.protoAction === "ignore" || options.protoAction === "preserve") {
_options.protoAction = options.protoAction;
} else {
throw new Error(
`Incorrect value for protoAction option, must be "error", "ignore" or undefined but passed ${options.protoAction}`
);
}
}
}
let at, // The index of the current character
ch, // The current character
escapee = {
'"': '"',
"\\": "\\",
"/": "/",
b: "\b",
f: "\f",
n: "\n",
r: "\r",
t: "\t",
},
text,
error = function (m) {
// Call error when something is wrong.
throw {
name: "SyntaxError",
message: m,
at: at,
text: text,
};
},
next = function (c) {
// If a c parameter is provided, verify that it matches the current character.
if (c && c !== ch) {
error("Expected '" + c + "' instead of '" + ch + "'");
}
// Get the next character. When there are no more characters,
// return the empty string.
ch = text.charAt(at);
at += 1;
return ch;
},
number = function () {
// Parse a number value.
let number,
string = "";
if (ch === "-") {
string = "-";
next("-");
}
while (ch >= "0" && ch <= "9") {
string += ch;
next();
}
if (ch === ".") {
string += ".";
while (next() && ch >= "0" && ch <= "9") {
string += ch;
}
}
if (ch === "e" || ch === "E") {
string += ch;
next();
if (ch === "-" || ch === "+") {
string += ch;
next();
}
while (ch >= "0" && ch <= "9") {
string += ch;
next();
}
}
number = +string;
if (!isFinite(number)) {
error("Bad number");
} else {
if (Number.isSafeInteger(number)) return !_options.alwaysParseAsBig ? number : BigInt(number);
// Number with fractional part should be treated as number(double) including big integers in scientific notation, i.e 1.79e+308
else return _options.storeAsString ? string : /[.eE]/.test(string) ? number : BigInt(string);
}
},
string = function () {
// Parse a string value.
let hex,
i,
string = "",
uffff;
// When parsing for string values, we must look for " and \ characters.
if (ch === '"') {
let startAt = at;
while (next()) {
if (ch === '"') {
if (at - 1 > startAt) string += text.substring(startAt, at - 1);
next();
return string;
}
if (ch === "\\") {
if (at - 1 > startAt) string += text.substring(startAt, at - 1);
next();
if (ch === "u") {
uffff = 0;
for (i = 0; i < 4; i += 1) {
hex = parseInt(next(), 16);
if (!isFinite(hex)) {
break;
}
uffff = uffff * 16 + hex;
}
string += String.fromCharCode(uffff);
} else if (typeof escapee[ch] === "string") {
string += escapee[ch];
} else {
break;
}
startAt = at;
}
}
}
error("Bad string");
},
white = function () {
// Skip whitespace.
while (ch && ch <= " ") {
next();
}
},
word = function () {
// true, false, or null.
switch (ch) {
case "t":
next("t");
next("r");
next("u");
next("e");
return true;
case "f":
next("f");
next("a");
next("l");
next("s");
next("e");
return false;
case "n":
next("n");
next("u");
next("l");
next("l");
return null;
}
error("Unexpected '" + ch + "'");
},
value, // Place holder for the value function.
array = function () {
// Parse an array value.
let array = [];
if (ch === "[") {
next("[");
white();
if (ch === "]") {
next("]");
return array; // empty array
}
while (ch) {
array.push(value());
white();
if (ch === "]") {
next("]");
return array;
}
next(",");
white();
}
}
error("Bad array");
},
object = function () {
// Parse an object value.
let key,
object = Object.create(null);
if (ch === "{") {
next("{");
white();
if (ch === "}") {
next("}");
return object; // empty object
}
while (ch) {
key = string();
white();
next(":");
if (_options.strict === true && Object.hasOwnProperty.call(object, key)) {
error('Duplicate key "' + key + '"');
}
if (suspectProtoRx.test(key) === true) {
if (_options.protoAction === "error") {
error("Object contains forbidden prototype property");
} else if (_options.protoAction === "ignore") {
value();
} else {
object[key] = value();
}
} else if (suspectConstructorRx.test(key) === true) {
if (_options.constructorAction === "error") {
error("Object contains forbidden constructor property");
} else if (_options.constructorAction === "ignore") {
value();
} else {
object[key] = value();
}
} else {
object[key] = value();
}
white();
if (ch === "}") {
next("}");
return object;
}
next(",");
white();
}
}
error("Bad object");
};
value = function () {
// Parse a JSON value. It could be an object, an array, a string, a number,
// or a word.
white();
switch (ch) {
case "{":
return object();
case "[":
return array();
case '"':
return string();
case "-":
return number();
default:
return ch >= "0" && ch <= "9" ? number() : word();
}
};
// Return the json_parse function. It will have access to all of the above
// functions and variables.
return function (source, reviver) {
let result;
text = source + "";
at = 0;
ch = " ";
result = value();
white();
if (ch) {
error("Syntax error");
}
// If there is a reviver function, we recursively walk the new structure,
// passing each name/value pair to the reviver function for possible
// transformation, starting with a temporary root object that holds the result
// in an empty key. If there is not a reviver function, we simply return the
// result.
return typeof reviver === "function"
? (function walk(holder, key) {
let v,
value = holder[key];
if (value && typeof value === "object") {
Object.keys(value).forEach(function (k) {
v = walk(value, k);
if (v !== undefined) {
value[k] = v;
} else {
delete value[k];
}
});
}
return reviver.call(holder, key, value);
})({ "": result }, "")
: result;
};
};
// parseJSON is a wrapper for JSONbig.parse that returns an error rather than
// throwing an error. JSONbig is an alternative to JSON.parse that decodes
// every number as a bigint. This is required when working with the skyd API
// because the skyd API uses 64 bit precision for all of its numbers, and
// therefore cannot be parsed losslessly by javascript. The skyd API is
// cryptographic, therefore full precision is required.
function parseJSON(json: string): [any, Err] {
try {
let obj = json_parse({ alwaysParseAsBig: true })(json);
return [obj, null];
} catch (err: any) {
return [{}, objAsString(err)];
}
}
export { parseJSON };