#25 parse very big numeric values

index.d.ts

@@ -0,0 +1,47 @@
+export declare type JSONBig = {
+  /**
+   * Converts a JavaScript Object Notation (JSON) string into an object.
+   * @param text A valid JSON string.
+   * @param reviver A function that transforms the results. This function is called for each member of the object.
+   * If a member contains nested objects, the nested objects are transformed before the parent object is.
+   */
+  parse(text: string, reviver?: (this: any, key: string, value: any) => any): any;
+
+  /**
+   * Converts a JavaScript value to a JavaScript Object Notation (JSON) string.
+   * @param value A JavaScript value, usually an object or array, to be converted.
+   * @param replacer A function that transforms the results.
+   * @param space Adds indentation, white space, and line break characters to the return-value JSON text to make it easier to read.
+   */
+  stringify(value: any, replacer?: (this: any, key: string, value: any) => any, space?: string | number): string;
+
+  /**
+   * Converts a JavaScript value to a JavaScript Object Notation (JSON) string.
+   * @param value A JavaScript value, usually an object or array, to be converted.
+   * @param replacer An array of strings and numbers that acts as a approved list for selecting the object properties that will be stringified.
+   * @param space Adds indentation, white space, and line break characters to the return-value JSON text to make it easier to read.
+   */
+  stringify(value: any, replacer?: (number | string)[] | null, space?: string | number): string;
+}
+
+
+export interface JSONBigParseOptions {
+  /**
+   * Not being strict means do not generate syntax errors for "duplicate key".
+   * @default false
+   */
+  strict?: boolean;
+
+  /**
+   * Whether the values should be stored as BigNumber (default) or a string
+   * @default false
+   */
+  storeAsString?: boolean;
+}
+
+
+declare const JSONbig: JSONBig & {
+  (options: JSONBigParseOptions): JSONBig;
+}
+
+export default JSONbig

lib/parse.js

@@ -202,24 +202,28 @@ var json_parse = function (options) {
         }
       }
       number = +string;
-      if (!isFinite(number)) {
-        error('Bad number');
+
+      if (BigNumber == null)
+        BigNumber = require('bignumber.js');
+        var bigNumberValue = new BigNumber(string);
+      if (!bigNumberValue.isFinite()) {
+        error("Bad number");
       } else {
-        if (BigNumber == null) BigNumber = require('bignumber.js');
         //if (number > 9007199254740992 || number < -9007199254740992)
         // Bignumber has stricter check: everything with length > 15 digits disallowed
-        if (string.length > 15)
+
+        if (bigNumberValue.toFixed().length > 15)
           return _options.storeAsString
             ? string
             : _options.useNativeBigInt
             ? BigInt(string)
-            : new BigNumber(string);
+            : bigNumberValue;
         else
           return !_options.alwaysParseAsBig
             ? number
             : _options.useNativeBigInt
             ? BigInt(number)
-            : new BigNumber(number);
+            : bigNumberValue;
       }
     },
     string = function () {

package.json

@@ -9,7 +9,7 @@
     "lib/stringify.js"
   ],
   "scripts": {
-    "test": "./node_modules/mocha/bin/mocha -R spec --check-leaks test/*-test.js"
+    "test": "mocha -R spec --check-leaks test/*-test.js"
   },
   "repository": {
     "type": "git",
@@ -29,6 +29,6 @@
   },
   "devDependencies": {
     "chai": "4.2.0",
-    "mocha": "8.0.1"
+    "mocha": "8.1.1"
   }
 }

test/bigint-test.js

@@ -1,8 +1,5 @@
-var mocha  = require('mocha')
-  , assert = require('chai').assert
-  , expect = require('chai').expect
-  , BigNumber = require('bignumber.js')
-  ;
+var expect = require('chai').expect,
+    BigNumber = require('bignumber.js');
 
 describe("Testing bigint support", function(){
     var input = '{"big":9223372036854775807,"small":123}';
@@ -28,4 +25,17 @@ describe("Testing bigint support", function(){
         expect(output).to.equal(input);
         done();
     });
+
+    it("Should be able to parse numeric values larger than 1.7976931348623157e+308", function(done){
+        var JSONbig = require('../index');
+        var veryBigInput = '{"big":3e+500}';
+
+        var obj = JSONbig.parse(veryBigInput);
+        expect(obj.big.toString(), "string from big int").to.equal("3e+500");
+        expect(obj.big, "instanceof big int").to.be.instanceof(BigNumber);
+
+        var output = JSONbig.stringify(obj);
+        expect(output).to.equal(veryBigInput);
+        done();
+    });
 });