Add BigInt support

Author: blakeembrey

src/index.spec.ts

@@ -218,7 +218,7 @@ describe("javascript-stringify", () => {
       });
 
       describe(
-        "should not take the names of their keys",
+        "omit the names of their keys",
         cases(["{name:function () {}}", "{'tricky name':function () {}}"])
       );
     });
@@ -250,6 +250,10 @@ describe("javascript-stringify", () => {
         it("should stringify", test(Buffer.from("test"), "new Buffer('test')"));
       });
 
+      describeIf("BigInt", typeof (BigInt as any) === "function", () => {
+        it("should stringify", test(BigInt("10"), "BigInt('10')"));
+      });
+
       describe("Error", () => {
         it("should stringify", test(new Error("test"), "new Error('test')"));
       });

src/stringify.ts

@@ -18,6 +18,9 @@ const PRIMITIVE_TYPES: Record<string, ToString> = {
     // ES2018 `Symbol.description`.
     return `Symbol(${next((value as any).description)})`;
   },
+  bigint: (value: bigint, space: string, next: Next) => {
+    return `BigInt(${next(String(value))})`;
+  },
   undefined: String,
   object: objectToString,
   function: functionToString