@theguild/federation-composition/esm/subgraph/context.js

Open Source Composition library for Apollo Federation

const notAReference = {
    context: undefined,
    selection: undefined,
};
export function parseContextReference(input) {
    let pos = skipIgnoredTokens(input, 0);
    if (input[pos] !== "$") {
        return notAReference;
    }
    pos = skipIgnoredTokens(input, pos + 1);
    if (!isNameStart(input[pos])) {
        return notAReference;
    }
    const contextStart = pos++;
    while (isNameContinue(input[pos])) {
        pos++;
    }
    return {
        context: input.slice(contextStart, pos),
        selection: input.slice(pos),
    };
}
export function isValidContextName(name) {
    if (!isAsciiLetter(name[0])) {
        return false;
    }
    for (let pos = 1; pos < name.length; pos++) {
        if (!isAsciiLetter(name[pos]) && !isDigit(name[pos])) {
            return false;
        }
    }
    return true;
}
function skipIgnoredTokens(input, start) {
    let pos = start;
    while (pos < input.length) {
        const char = input[pos];
        if (char === " " ||
            char === "\t" ||
            char === "\n" ||
            char === "\r" ||
            char === "," ||
            char === "\ufeff") {
            pos++;
            continue;
        }
        if (char === "#") {
            pos++;
            while (pos < input.length && input[pos] !== "\n" && input[pos] !== "\r") {
                pos++;
            }
            continue;
        }
        break;
    }
    return pos;
}
function isNameStart(char) {
    return char === "_" || isAsciiLetter(char);
}
function isNameContinue(char) {
    return isNameStart(char) || isDigit(char);
}
function isAsciiLetter(char) {
    if (!char) {
        return false;
    }
    const code = char.charCodeAt(0);
    return ((code >= 65 && code <= 90) ||
        (code >= 97 && code <= 122));
}
function isDigit(char) {
    if (!char) {
        return false;
    }
    const code = char.charCodeAt(0);
    return code >= 48 && code <= 57;
}