X-Git-Url: https://git.ladys.computer/Pisces/blobdiff_plain/0fb1e53a1e78a6bf490cd95cf92a744d3ac6171f..beab7268e7673b036222e64aac924f850e2b976e:/object.test.js

diff --git a/object.test.js b/object.test.js
index fc62be3..a2e718b 100644
--- a/object.test.js
+++ b/object.test.js
@@ -35,6 +35,7 @@ import {
   hasOwnProperty,
   hasProperty,
   isArraylikeObject,
+  isConcatSpreadableObject,
   isExtensibleObject,
   isUnfrozenObject,
   isUnsealedObject,
@@ -1588,6 +1589,62 @@ describe("isArraylikeObject", () => {
   });
 });
 
+describe("isConcatSpreadableObject", () => {
+  it("[[Call]] returns false for primitives", () => {
+    assertStrictEquals(isConcatSpreadableObject("failure"), false);
+  });
+
+  it("[[Call]] returns false if [Symbol.isConcatSpreadable] is null or false", () => {
+    assertStrictEquals(
+      isConcatSpreadableObject(
+        Object.assign([], { [Symbol.isConcatSpreadable]: null }),
+      ),
+      false,
+    );
+    assertStrictEquals(
+      isConcatSpreadableObject(
+        Object.assign([], { [Symbol.isConcatSpreadable]: false }),
+      ),
+      false,
+    );
+  });
+
+  it("[[Call]] returns true if [Symbol.isConcatSpreadable] is undefined and the object is an array", () => {
+    assertStrictEquals(
+      isConcatSpreadableObject(
+        Object.assign([], { [Symbol.isConcatSpreadable]: undefined }),
+      ),
+      true,
+    );
+  });
+
+  it("[[Call]] returns true if [Symbol.isConcatSpreadable] is true", () => {
+    assertStrictEquals(
+      isConcatSpreadableObject({ [Symbol.isConcatSpreadable]: true }),
+      true,
+    );
+  });
+
+  it("[[Construct]] throws an error", () => {
+    assertThrows(() => new isConcatSpreadableObject({}));
+  });
+
+  describe(".length", () => {
+    it("[[Get]] returns the correct length", () => {
+      assertStrictEquals(isConcatSpreadableObject.length, 1);
+    });
+  });
+
+  describe(".name", () => {
+    it("[[Get]] returns the correct name", () => {
+      assertStrictEquals(
+        isConcatSpreadableObject.name,
+        "isConcatSpreadableObject",
+      );
+    });
+  });
+});
+
 describe("isExtensibleObject", () => {
   it("[[Call]] returns true for extensible objects", () => {
     assertStrictEquals(isExtensibleObject({}), true);