Bug 171197 – test262: test262/test/built-ins/Number/prototype/toPrecision/nan.js

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Joseph Pecoraro]

test262/test/built-ins/Number/prototype/toPrecision/nan.js and related

Test:

    NaN.toPrecision(Infinity)

Expected:
"NaN"

Actual:
RangeError: toPrecision() argument must be between 1 and 21

Notes:
- Order of operations here need to be refined slightly
- Chrome and Firefox pass

Spec:
https://tc39.github.io/ecma262/#sec-number.prototype.toprecision
20.1.3.5 Number.prototype.toPrecision ( precision )

> 1. Let x be ? thisNumberValue(this value).
> 2. If precision is undefined, return ! ToString(x).
> 3. Let p be ? ToInteger(precision).
> 4. If x is NaN, return the String "NaN".
> 5. Let s be the empty String.
> 6. If x < 0, then
>   a. Let s be code unit 0x002D (HYPHEN-MINUS).
>   b. Let x be -x.
> 7. If x = +∞, then
>   a. Return the String that is the concatenation of s and "Infinity".
> 8. If p < 1 or p > 21, throw a RangeError exception. However, an implementation is permitted to extend the behaviour of toPrecision for values of p less than 1 or greater than 21. In this case toPrecision would not necessarily throw RangeError for such values.
> ...

https://tc39.github.io/ecma262/#sec-number.prototype.toexponential
20.1.3.2 Number.prototype.toExponential ( fractionDigits )

> 1. Let x be ? thisNumberValue(this value).
> 2. Let f be ? ToInteger(fractionDigits).
> 3. Assert: f is 0, when fractionDigits is undefined.
> 4. If x is NaN, return the String "NaN".
> 5. Let s be the empty String.
> 6. If x < 0, then
>   a. Let s be "-".
>   b. Let x be -x.
> 7. If x = +∞, then
>   a. Return the concatenation of the Strings s and "Infinity".
> 8. If f < 0 or f > 20, throw a RangeError exception. However, an implementation is permitted to extend the behaviour of toExponential for values of f less than 0 or greater than 20. In this case toExponential would not necessarily throw RangeError for such values.
> ...

[Joseph Pecoraro]

Created attachment 307937 [details]
[PATCH] Proposed Fix

[Saam Barati]

Comment on attachment 307937 [details]
[PATCH] Proposed Fix

View in context: https://bugs.webkit.org/attachment.cgi?id=307937&action=review

r=me

> Source/JavaScriptCore/runtime/NumberPrototype.cpp:404
> +    RETURN_IF_EXCEPTION(scope, encodedJSValue());

style nit: We've been doing: `RETURN_IF_EXCEPTION(scope, { });` in most places.

[Joseph Pecoraro]

Created attachment 307940 [details]
[PATCH] For Landing

[WebKit Commit Bot]

The commit-queue encountered the following flaky tests while processing attachment 307940 [details]:

webrtc/datachannel/basic.html bug 171203 (author: [e-mail])
The commit-queue is continuing to process your patch.

[WebKit Commit Bot]

Comment on attachment 307940 [details]
[PATCH] For Landing

Clearing flags on attachment: 307940

Committed r215679: <http://trac.webkit.org/changeset/215679>