| "use strict"; |
| |
| test(() => { |
| assert_own_property(Blob.prototype, Symbol.toStringTag); |
| |
| const propDesc = Object.getOwnPropertyDescriptor(Blob.prototype, Symbol.toStringTag); |
| assert_equals(propDesc.value, "Blob", "value"); |
| assert_equals(propDesc.configurable, true, "configurable"); |
| assert_equals(propDesc.enumerable, false, "enumerable"); |
| assert_equals(propDesc.writable, false, "writable"); |
| }, "@@toStringTag exists on the prototype with the appropriate descriptor"); |
| |
| test(() => { |
| assert_not_own_property(new Blob(), Symbol.toStringTag); |
| }, "@@toStringTag must not exist on the instance"); |
| |
| test(() => { |
| assert_equals(Object.prototype.toString.call(Blob.prototype), "[object Blob]"); |
| }, "Object.prototype.toString applied to the prototype"); |
| |
| test(() => { |
| assert_equals(Object.prototype.toString.call(new Blob()), "[object Blob]"); |
| }, "Object.prototype.toString applied to an instance"); |
| |
| test(t => { |
| assert_own_property(Blob.prototype, Symbol.toStringTag, "Precondition for this test: @@toStringTag on the prototype"); |
| |
| t.add_cleanup(() => { |
| Object.defineProperty(Blob.prototype, Symbol.toStringTag, { value: "Blob" }); |
| }); |
| |
| Object.defineProperty(Blob.prototype, Symbol.toStringTag, { value: "NotABlob" }); |
| assert_equals(Object.prototype.toString.call(Blob.prototype), "[object NotABlob]", "prototype"); |
| assert_equals(Object.prototype.toString.call(new Blob()), "[object NotABlob]", "instance"); |
| }, "Object.prototype.toString applied after modifying the prototype's @@toStringTag"); |
| |
| test(t => { |
| const instance = new Blob(); |
| assert_not_own_property(instance, Symbol.toStringTag, "Precondition for this test: no @@toStringTag on the instance"); |
| |
| Object.defineProperty(instance, Symbol.toStringTag, { value: "NotABlob" }); |
| assert_equals(Object.prototype.toString.call(instance), "[object NotABlob]"); |
| }, "Object.prototype.toString applied to the instance after modifying the instance's @@toStringTag"); |
| |
| // Chrome had a bug (https://bugs.chromium.org/p/chromium/issues/detail?id=793406) where if there |
| // was no @@toStringTag in the prototype, it would fall back to a magic class string. This tests |
| // that the bug is fixed. |
| |
| test(() => { |
| const instance = new Blob(); |
| Object.setPrototypeOf(instance, null); |
| |
| assert_equals(Object.prototype.toString.call(instance), "[object Object]"); |
| }, "Object.prototype.toString applied to a null-prototype instance"); |
| |
| // This test must be last. |
| test(() => { |
| delete Blob.prototype[Symbol.toStringTag]; |
| |
| assert_equals(Object.prototype.toString.call(Blob.prototype), "[object Object]", "prototype"); |
| assert_equals(Object.prototype.toString.call(new Blob()), "[object Object]", "instance"); |
| }, "Object.prototype.toString applied after deleting @@toStringTag"); |