@chubbyts/chubbyts-negotiation/dist/accept-negotiator.js

A simple negotiation library.

import { resolveHeaderToMap } from './negotiation.js';
const escapeStringRegexp = (regex) => {
    return regex.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
};
const compareMediaTypeWithTypeOnly = (supportedValues, mediaType, attributes) => {
    const mediaTypeParts = mediaType.match(/([^/+]+)\/\*/);
    if (null === mediaTypeParts) {
        return undefined;
    }
    for (const supportedValue of supportedValues) {
        if (null !== supportedValue.match(new RegExp('^' + escapeStringRegexp(mediaTypeParts[1]) + '/'))) {
            return { value: supportedValue, attributes };
        }
    }
    return undefined;
};
const compareMediaTypes = (supportedValues, suffixSupportedValues, headerToMap) => {
    for (const [mediaType, attributes] of headerToMap.entries()) {
        if (-1 !== supportedValues.indexOf(mediaType)) {
            return { value: mediaType, attributes };
        }
    }
    for (const [mediaType, attributes] of headerToMap.entries()) {
        if (suffixSupportedValues.has(mediaType)) {
            return { value: suffixSupportedValues.get(mediaType), attributes };
        }
    }
    for (const [mediaType, attributes] of headerToMap.entries()) {
        const negotiatedValue = compareMediaTypeWithTypeOnly(supportedValues, mediaType, attributes);
        if (undefined !== negotiatedValue) {
            return negotiatedValue;
        }
    }
    if (headerToMap.has('*/*')) {
        return { value: supportedValues[0], attributes: headerToMap.get('*/*') };
    }
    return undefined;
};
export const createAcceptNegotiator = (supportedValues) => {
    const suffixSupportedValues = new Map(supportedValues.map((supportedValue) => {
        const supportedValueParts = supportedValue.match(/([^/+]+)\/([^/+]+)\+([^/+]+)/);
        return [
            null !== supportedValueParts ? supportedValueParts[1] + '/' + supportedValueParts[3] : undefined,
            supportedValue,
        ];
    }));
    return {
        negotiate: (header) => {
            const headerToMap = resolveHeaderToMap(header);
            return compareMediaTypes(supportedValues, suffixSupportedValues, headerToMap);
        },
        supportedValues,
    };
};