Issue with "Intl.NumberFormat.prototype.formatToParts()": type: 'compact' is missing

[mjpieters]

MDN URL: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/formatToParts

What information was incorrect, unhelpful, or incomplete?

The list of 'possible types' is incomplete, when using Intl.NumberFormat({notation: 'compact'}).formatToParts(number) the magnitude of the value is passed in as a part with type: 'compact'

Specific section or headline?

Description, under the Possible types are the following: list.

What did you expect to see?

`'compact' is missing in this list, as per EMCA 402, section 12.1.7 (PartitionNotationSubPattern), step 4. - c. - iv. - 2.:

iv. Else if p is equal to "compactSymbol", then

1. [...]
2. Append a new Record { [[Type]]: "compact", [[Value]]: compactSymbol } as the last element of result.

as well as step 4. - c. - v. - 2.:

v. Else if p is equal to "compactName", then

1. [...]
2. Append a new Record { [[Type]]: "compact", [[Value]]: compactName } as the last element of result.

Did you test this? If so, how?

JavaScript code using the part type:

const compactFormat = Intl.NumberFormat('en', {
    notation: 'compact',
    compactDisplay: 'short',
    style: 'decimal',
    maximumFractionDigits: 3,
});

// formatValue(42174812) => {formatted: '42.175', magnitude: 'M'}
function formatValue(value) {
    let magnitude = '';
    return {
        formatted: compactFormat
            .formatToParts(value)
            .reduce((formatted, part) => {
            switch (part.type) {
                case 'compact':
                    magnitude = magnitude + part.value;
                    break;
                default:
                    formatted = formatted + part.value;
            }
            return formatted;
        }, ''),
        magnitude: magnitude
    };
}

console.log(formatValue(42174812));

outputs

Object { formatted: "42.175", magnitude: "M" }

MDN Content page report details

• Folder: en-us/web/javascript/reference/global_objects/intl/numberformat/formattoparts
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/NumberFormat/formatToParts
• GitHub URL: https://github.com/mdn/content/blob/master/files/en-us/web/javascript/reference/global_objects/intl/numberformat/formattoparts/index.html
• Report started: 2020-12-21T12:59:30.442Z

[mjpieters]

I've parsed the spec source, extracting all [[Type]]: *"..."* references, which reveals a few more options that are missing:

• 12.1.6 PartitionNumberPattern:
  • step 8. - l.: 'unknown'

The same type is also possible via 12.1.7, step 4. - c. - viii.

• 12.1.7 PartitionNotationSubPattern:
  • step 4. - c. - vi. - 2.: 'exponentSeparator'
  • step 4. - c. - vii. - 1. - b.: 'exponentMinusSign'
  • step 4. - c. - vii. - 3.: 'exponentInteger'