1 files changed, 71 insertions, 0 deletions
diff --git a/Libraries/LibJS/Tests/JSON.stringify.js b/Libraries/LibJS/Tests/JSON.stringify.js
new file mode 100644
index 0000000000..d071ea961b
--- /dev/null
+++ b/Libraries/LibJS/Tests/JSON.stringify.js
@@ -0,0 +1,71 @@
+load("test-common.js");
+
+try {
+    assert(JSON.stringify.length === 3);
+
+    assertThrowsError(() => {
+        JSON.stringify(5n);
+    }, {
+        error: TypeError,
+        message: "Cannot serialize BigInt value to JSON",
+    });
+
+    const properties = [
+        [5, "5"],
+        [undefined, undefined],
+        [null, "null"],
+        [NaN, "null"],
+        [-NaN, "null"],
+        [Infinity, "null"],
+        [-Infinity, "null"],
+        [true, "true"],
+        [false, "false"],
+        ["test", '"test"'],
+        [new Number(5), "5"],
+        [new Boolean(false), "false"],
+        [new String("test"), '"test"'],
+        [() => {}, undefined],
+        [[1, 2, "foo"], '[1,2,"foo"]'],
+        [{ foo: 1, bar: "baz", qux() {} }, '{"foo":1,"bar":"baz"}'],
+        [
+            {
+                var1: 1,
+                var2: 2,
+                toJSON(key) {
+                    let o = this;
+                    o.var2 = 10;
+                    return o;
+                }
+            },
+            '{"var1":1,"var2":10}',
+        ],
+    ];
+
+    properties.forEach(testCase => {
+        assert(JSON.stringify(testCase[0]) === testCase[1]);
+    });
+
+    let bad1 = {};
+    bad1.foo = bad1;
+    let bad2 = [];
+    bad2[5] = [[[bad2]]];
+
+    let bad3a = { foo: "bar" };
+    let bad3b = [1, 2, bad3a];
+    bad3a.bad = bad3b;
+
+    [bad1, bad2, bad3a].forEach(bad => assertThrowsError(() => {
+        JSON.stringify(bad);
+    }, {
+        error: TypeError,
+        message: "Cannot stringify circular object",
+    }));
+
+    let o = { foo: "bar" };
+    Object.defineProperty(o, "baz", { value: "qux", enumerable: false });
+    assert(JSON.stringify(o) === '{"foo":"bar"}');
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}