@azure/msal-common/src/error/PlatformBrokerError.ts

Microsoft Authentication Library for js

/*
 * Copyright (c) Microsoft Corporation. All rights reserved.
 * Licensed under the MIT License.
 */

import { AuthError } from "./AuthError.js";

/**
 * Converts a numeric tag from MSAL Runtime to a 5-character string representation.
 * Tags are encoded as 30-bit values (6 bits per character) using a custom symbol space.
 * @param tag - The numeric tag to convert
 * @returns The string representation of the tag
 */
function tagToString(tag: number): string {
    if (tag === 0) {
        return "UNTAG";
    }

    const tagSymbolSpace =
        "abcdefghijklmnopqrstuvwxyz0123456789****************************";
    let tagBuffer = "*****";

    const chars = [
        tagSymbolSpace[(tag >> 24) & 0x3f],
        tagSymbolSpace[(tag >> 18) & 0x3f],
        tagSymbolSpace[(tag >> 12) & 0x3f],
        tagSymbolSpace[(tag >> 6) & 0x3f],
        tagSymbolSpace[(tag >> 0) & 0x3f],
    ];

    tagBuffer = chars.join("");

    return tagBuffer;
}

/**
 * Error class for MSAL Runtime errors that preserves detailed broker information
 */
export class PlatformBrokerError extends AuthError {
    /**
     * Numeric error code from MSAL Runtime
     */
    public statusCode: number;

    /**
     * Error tag from MSAL Runtime
     */
    public tag: string;

    constructor(
        errorStatus: string,
        errorContext: string,
        errorCode: number,
        errorTag: number
    ) {
        const tagString = tagToString(errorTag);
        const enhancedErrorContext = errorContext
            ? `${errorContext} (Error Code: ${errorCode}, Tag: ${tagString})`
            : `(Error Code: ${errorCode}, Tag: ${tagString})`;

        super(errorStatus, enhancedErrorContext);
        this.name = "PlatformBrokerError";
        this.statusCode = errorCode;
        this.tag = tagString;
        Object.setPrototypeOf(this, PlatformBrokerError.prototype);
    }
}