feat: support safeDestr

README.md

@@ -28,16 +28,16 @@ Import into your Node.js project:
 
 ```js
 // CommonJS
-const { destr } = require("destr");
+const { destr, safeDestr } = require("destr");
 
 // ESM
-import { destr } from "destr";
+import { destr, safeDestr } from "destr";
 ```
 
 ### Deno
 
 ```js
-import { destr } from "https://deno.land/x/destr/src/index.ts";
+import { destr, safeDestr } from "https://deno.land/x/destr/src/index.ts";
 
 console.log(destr('{ "deno": "yay" }'));
 ```
@@ -98,14 +98,14 @@ destr(input);
 
 ### Strict Mode
 
-If `{ strict: true }` passed as second argument, `destr` will throw an error if the input is not a valid JSON string or parsing fails. (non string values and built-ins will be still returned as-is)
+When using `safeDestr` it will throw an error if the input is not a valid JSON string or parsing fails. (non string values and built-ins will be still returned as-is)
 
 ```js
 // Returns "[foo"
-destr("[foo");
+safeDestr("[foo");
 
 // Throws an error
-destr("[foo", { strict: true });
+safeDestr("[foo", { strict: true });
 ```
 
 ## Benchmarks

lib/index.cjs

@@ -1,6 +1,7 @@
-const { destr } = require("../dist/index.cjs");
+const { destr, safeDestr } = require("../dist/index.cjs");
 
 // Allow mixed default and named exports
 destr.destr = destr;
+destr.safeDestr = safeDestr;
 
 module.exports = destr;

src/index.ts

@@ -60,13 +60,16 @@
 
   if (!JsonSigRx.test(value)) {
     if (options.strict) {
-      throw new SyntaxError("Invalid JSON");
+      throw new SyntaxError("[destr] Invalid JSON");
     }
     return value as T;
   }
 
   try {
     if (suspectProtoRx.test(value) || suspectConstructorRx.test(value)) {
+      if (options.strict) {
+        throw new Error("[destr] Possible prototype pollution");
+      }
       return JSON.parse(value, jsonParseTransform);
     }
     return JSON.parse(value);
@@ -78,4 +81,8 @@
   }
 }
 
+export function safeDestr<T = unknown>(value: any, options: Options = {}): T {
+  return destr<T>(value, { ...options, strict: true });
+}
+
 export default destr;

test/index.test.ts

@@ -1,5 +1,5 @@
 import { expect, it, describe, vi } from "vitest";
-import { destr } from "../src";
+import { destr, safeDestr } from "../src";
 
 describe("destr", () => {
   it("returns the passed value if it's not a string", () => {
@@ -107,7 +107,7 @@ describe("destr", () => {
     }
   });
 
-  it("returns the passed string if it's a invalid JSON text and `strict` option is set `false`", () => {
+  it("returns the passed string if it's a invalid JSON text by default", () => {
     const testCases = [
       { input: "{     " },
       { input: "[     " },
@@ -121,7 +121,7 @@ describe("destr", () => {
     }
   });
 
-  it("throws an error if it's a invalid JSON texts and `strict` option is set `true`", () => {
+  it("throws an error if it's a invalid JSON texts with safeDestr", () => {
     const testCases = [
       { input: "{     ", output: "Unexpected end of JSON input" },
       { input: "[     ", output: "Unexpected end of JSON input" },
@@ -131,7 +131,7 @@ describe("destr", () => {
     ];
 
     for (const testCase of testCases) {
-      expect(() => destr(testCase.input, { strict: true })).toThrowError(
+      expect(() => safeDestr(testCase.input)).toThrowError(
         testCase.output || ""
       );
     }