export function getErrorMsg()

in server/aws-lsp-codewhisperer/src/shared/utils.ts [37:87]
20 lines of code
9 McCabe index (conditional complexity)

export function getErrorMsg(err: Error | undefined, withCause: boolean = false): string | undefined {
    if (err === undefined) {
        return undefined
    }

    // Non-standard SDK fields added by the OIDC service, to conform to the OAuth spec
    // (https://datatracker.ietf.org/doc/html/rfc6749#section-4.1.2.1) :
    // - error: code per the OAuth spec
    // - error_description: improved error message provided by OIDC service. Prefer this to
    //   `message` if present.
    //   https://github.com/aws/aws-toolkit-jetbrains/commit/cc9ed87fa9391dd39ac05cbf99b4437112fa3d10
    // - error_uri: not provided by OIDC currently?
    //
    // Example:
    //
    //      [error] API response (oidc.us-east-1.amazonaws.com /token): {
    //        name: 'InvalidGrantException',
    //        '$fault': 'client',
    //        '$metadata': {
    //          httpStatusCode: 400,
    //          requestId: '7f5af448-5af7-45f2-8e47-5808deaea4ab',
    //          extendedRequestId: undefined,
    //          cfId: undefined
    //        },
    //        error: 'invalid_grant',
    //        error_description: 'Invalid refresh token provided',
    //        message: 'UnknownError'
    //      }
    const anyDesc = (err as any).error_description
    const errDesc = typeof anyDesc === 'string' ? anyDesc.trim() : ''
    let msg = errDesc !== '' ? errDesc : err.message?.trim()

    if (typeof msg !== 'string') {
        return undefined
    }

    // append the cause's message
    if (withCause) {
        const errorId = getErrorId(err)
        // - prepend id to message
        // - If a generic error does not have the `name` field explicitly set, it returns a generic 'Error' name. So skip since it is useless.
        if (errorId && errorId !== 'Error') {
            msg = `${errorId}: ${msg}`
        }

        const cause = (err as any).cause
        return `${msg}${cause ? ' | ' + getErrorMsg(cause, withCause) : ''}`
    }

    return msg
}