promise-zy

2.1.2.1: When fulfilled, a promise: must not transition to any other state. √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ trying to fulfill then immediately reject √ trying to fulfill then reject, delayed √ trying to fulfill immediately then reject delayed 2.1.3.1: When rejected, a promise: must not transition to any other state. √ already-rejected √ immediately-rejected √ eventually-rejected √ trying to reject then immediately fulfill √ trying to reject then fulfill, delayed √ trying to reject immediately then fulfill delayed 2.2.1: Both `onFulfilled` and `onRejected` are optional arguments. 2.2.1.1: If `onFulfilled` is not a function, it must be ignored. applied to a directly-rejected promise √ `onFulfilled` is `undefined` √ `onFulfilled` is `null` √ `onFulfilled` is `false` √ `onFulfilled` is `5` √ `onFulfilled` is an object applied to a promise rejected and then chained off of √ `onFulfilled` is `undefined` √ `onFulfilled` is `null` √ `onFulfilled` is `false` √ `onFulfilled` is `5` √ `onFulfilled` is an object 2.2.1.2: If `onRejected` is not a function, it must be ignored. applied to a directly-fulfilled promise √ `onRejected` is `undefined` √ `onRejected` is `null` √ `onRejected` is `false` √ `onRejected` is `5` √ `onRejected` is an object applied to a promise fulfilled and then chained off of √ `onFulfilled` is `undefined` √ `onFulfilled` is `null` √ `onFulfilled` is `false` √ `onFulfilled` is `5` √ `onFulfilled` is an object 2.2.2: If `onFulfilled` is a function, 2.2.2.1: it must be called after `promise` is fulfilled, with `promise`’s fu lfillment value as its first argument. √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled 2.2.2.2: it must not be called before `promise` is fulfilled √ fulfilled after a delay √ never fulfilled 2.2.2.3: it must not be called more than once. √ already-fulfilled √ trying to fulfill a pending promise more than once, immediately √ trying to fulfill a pending promise more than once, delayed √ trying to fulfill a pending promise more than once, immediately then del ayed √ when multiple `then` calls are made, spaced apart in time √ when `then` is interleaved with fulfillment 2.2.3: If `onRejected` is a function, 2.2.3.1: it must be called after `promise` is rejected, with `promise`’s rej ection reason as its first argument. √ already-rejected √ immediately-rejected √ eventually-rejected 2.2.3.2: it must not be called before `promise` is rejected √ rejected after a delay √ never rejected 2.2.3.3: it must not be called more than once. √ already-rejected √ trying to reject a pending promise more than once, immediately √ trying to reject a pending promise more than once, delayed √ trying to reject a pending promise more than once, immediately then dela yed √ when multiple `then` calls are made, spaced apart in time √ when `then` is interleaved with rejection 2.2.4: `onFulfilled` or `onRejected` must not be called until the execution co ntext stack contains only platform code. `then` returns before the promise becomes fulfilled or rejected √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected Clean-stack execution ordering tests (fulfillment case) √ when `onFulfilled` is added immediately before the promise is fulfilled √ when `onFulfilled` is added immediately after the promise is fulfilled √ when one `onFulfilled` is added inside another `onFulfilled` √ when `onFulfilled` is added inside an `onRejected` √ when the promise is fulfilled asynchronously Clean-stack execution ordering tests (rejection case) √ when `onRejected` is added immediately before the promise is rejected √ when `onRejected` is added immediately after the promise is rejected √ when `onRejected` is added inside an `onFulfilled` √ when one `onRejected` is added inside another `onRejected` √ when the promise is rejected asynchronously 2.2.5 `onFulfilled` and `onRejected` must be called as functions (i.e. with no `this` value). strict mode √ fulfilled √ rejected sloppy mode √ fulfilled √ rejected 2.2.6: `then` may be called multiple times on the same promise. 2.2.6.1: If/when `promise` is fulfilled, all respective `onFulfilled` callba cks must execute in the order of their originating calls to `then`. multiple boring fulfillment handlers √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled multiple fulfillment handlers, one of which throws √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled results in multiple branching chains with their own fulfillment values √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled `onFulfilled` handlers are called in the original order √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled even when one handler is added inside another handler √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled 2.2.6.2: If/when `promise` is rejected, all respective `onRejected` callbacks must execute in the order of their originating calls to `then`. multiple boring rejection handlers √ already-rejected √ immediately-rejected √ eventually-rejected multiple rejection handlers, one of which throws √ already-rejected √ immediately-rejected √ eventually-rejected results in multiple branching chains with their own fulfillment values √ already-rejected √ immediately-rejected √ eventually-rejected `onRejected` handlers are called in the original order √ already-rejected √ immediately-rejected √ eventually-rejected even when one handler is added inside another handler √ already-rejected √ immediately-rejected √ eventually-rejected 2.2.7: `then` must return a promise: `promise2 = promise1.then(onFulfilled, onRejected)` √ is a promise 2.2.7.1: If either `onFulfilled` or `onRejected` returns a value `x`, run the Promise Resolution Procedure `[[Resolve]](promise2, x)` √ see separate 3.3 tests 2.2.7.2: If either `onFulfilled` or `onRejected` throws an exception `e`, `promise2` must be rejected with `e` as the reason. The reason is `undefined` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is `null` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is `false` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is `0` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is an error √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is an error without a stack √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is a date √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is an object √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is an always-pending thenable √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is a fulfilled promise √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected The reason is a rejected promise √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled √ already-rejected √ immediately-rejected √ eventually-rejected 2.2.7.3: If `onFulfilled` is not a function and `promise1` is fulfilled, `promise2` must be fulfilled with the same value. `onFulfilled` is `undefined` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled `onFulfilled` is `null` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled `onFulfilled` is `false` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled `onFulfilled` is `5` √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled `onFulfilled` is an object √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled `onFulfilled` is an array containing a function √ already-fulfilled √ immediately-fulfilled √ eventually-fulfilled 2.2.7.4: If `onRejected` is not a function and `promise1` is rejected, `promise2` must be rejected with the same reason. `onRejected` is `undefined` √ already-rejected √ immediately-rejected √ eventually-rejected `onRejected` is `null` √ already-rejected √ immediately-rejected √ eventually-rejected `onRejected` is `false` √ already-rejected √ immediately-rejected √ eventually-rejected `onRejected` is `5` √ already-rejected √ immediately-rejected √ eventually-rejected `onRejected` is an object √ already-rejected √ immediately-rejected √ eventually-rejected `onRejected` is an array containing a function √ already-rejected √ immediately-rejected √ eventually-rejected 2.3.1: If `promise` and `x` refer to the same object, reject `promise` with a `TypeError' as the reason. √ via return from a fulfilled promise √ via return from a rejected promise 2.3.2: If `x` is a promise, adopt its state 2.3.2.1: If `x` is pending, `promise` must remain pending until `x` is fulfilled or rejected. √ via return from a fulfilled promise √ via return from a rejected promise 2.3.2.2: If/when `x` is fulfilled, fulfill `promise` with the same value. `x` is already-fulfilled √ via return from a fulfilled promise √ via return from a rejected promise `x` is eventually-fulfilled √ via return from a fulfilled promise √ via return from a rejected promise 2.3.2.3: If/when `x` is rejected, reject `promise` with the same reason. `x` is already-rejected √ via return from a fulfilled promise √ via return from a rejected promise `x` is eventually-rejected √ via return from a fulfilled promise √ via return from a rejected promise 2.3.3: Otherwise, if `x` is an object or function, 2.3.3.1: Let `then` be `x.then` `x` is an object with null prototype √ via return from a fulfilled promise √ via return from a rejected promise `x` is an object with normal Object.prototype √ via return from a fulfilled promise √ via return from a rejected promise `x` is a function √ via return from a fulfilled promise √ via return from a rejected promise 2.3.3.2: If retrieving the property `x.then` results in a thrown exception `e`, reject `promise` with `e` as the reason. `e` is `undefined` √ via return from a fulfilled promise √ via return from a rejected promise `e` is `null` √ via return from a fulfilled promise √ via return from a rejected promise `e` is `false` √ via return from a fulfilled promise √ via return from a rejected promise `e` is `0` √ via return from a fulfilled promise √ via return from a rejected promise `e` is an error √ via return from a fulfilled promise √ via return from a rejected promise `e` is an error without a stack √ via return from a fulfilled promise √ via return from a rejected promise `e` is a date √ via return from a fulfilled promise √ via return from a rejected promise `e` is an object √ via return from a fulfilled promise √ via return from a rejected promise `e` is an always-pending thenable √ via return from a fulfilled promise √ via return from a rejected promise `e` is a fulfilled promise √ via return from a fulfilled promise √ via return from a rejected promise `e` is a rejected promise √ via return from a fulfilled promise √ via return from a rejected promise 2.3.3.3: If `then` is a function, call it with `x` as `this`, first argument `resolvePromise`, and second argument `rejectPromise` Calls with `x` as `this` and two function arguments √ via return from a fulfilled promise √ via return from a rejected promise Uses the original value of `then` √ via return from a fulfilled promise √ via return from a rejected promise 2.3.3.3.1: If/when `resolvePromise` is called with value `y`, run `[[Resolve]](promise, y)` `y` is not a thenable `y` is `undefined` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is `null` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is `false` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is `5` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an object `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an array `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable `y` is a synchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an already-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an eventually-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-rejected one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that immediately throws in `then` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an object with a throwing `then` accessor `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an already-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an eventually-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable for a thenable `y` is a synchronously-fulfilled custom thenable for a synchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for an asynchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for a synchronously-fulfilled one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for a thenable that tries to fulfill twice `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for a thenable that fulfills but then throws `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for an already-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for an eventually-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for a synchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for an asynchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for a synchronously-rejected one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for a thenable that immediately throws in `then` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for an object with a throwing `then` accessor `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for an already-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled custom thenable for an eventually-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for a synchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for an asynchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for a synchronously-fulfilled one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for a thenable that tries to fulfill twice `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for a thenable that fulfills but then throws `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for an already-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for an eventually-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for a synchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for an asynchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for a synchronously-rejected one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for a thenable that immediately throws in `then` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for an object with a throwing `then` accessor `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for an already-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is an asynchronously-fulfilled custom thenable for an eventually-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for a synchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for an asynchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for a synchronously-fulfilled one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for a thenable that tries to fulfill twice `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for a thenable that fulfills but then throws `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for an already-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for an eventually-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for a synchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for an asynchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for a synchronously-rejected one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for a thenable that immediately throws in `then` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for an object with a throwing `then` accessor `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for an already-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a synchronously-fulfilled one-time thenable for an eventually-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for a synchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for an asynchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for a synchronously-fulfilled one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for a thenable that tries to fulfill twice `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for a thenable that fulfills but then throws `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for an already-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for an eventually-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for a synchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for an asynchronously-rejected custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for a synchronously-rejected one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for a thenable that immediately throws in `then` `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for an object with a throwing `then` accessor `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for an already-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that tries to fulfill twice for an eventually-rejected promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws for a synchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws for an asynchronously-fulfilled custom thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws for a synchronously-fulfilled one-time thenable `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws for a thenable that tries to fulfill twice `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws for a thenable that fulfills but then throws `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws for an already-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise `then` calls `resolvePromise` asynchronously √ via return from a fulfilled promise √ via return from a rejected promise `y` is a thenable that fulfills but then throws for an eventually-fulfilled promise `then` calls `resolvePromise` synchronously √ via return from a fulfilled promise √ via return from a rejected promise