Function extractTransformCallbacks

nodejs/src/client.ts:303–335

* Extract transform callbacks from a system message config and prepare the wire payload. * Function-valued actions are replaced with `{ action: "transform" }` for serialization, * and the original callbacks are returned in a separate map.

(systemMessage: SessionConfig["systemMessage"])

 * and the original callbacks are returned in a separate map.
 */
function extractTransformCallbacks(systemMessage: SessionConfig["systemMessage"]): {
    wirePayload: SessionConfig["systemMessage"];
    transformCallbacks: Map<string, SectionTransformFn> | undefined;
} {
    if (!systemMessage || systemMessage.mode !== "customize" || !systemMessage.sections) {
        return { wirePayload: systemMessage, transformCallbacks: undefined };
    }

    const transformCallbacks = new Map<string, SectionTransformFn>();
    const wireSections: Record<string, { action: string; content?: string }> = {};

    for (const [sectionId, override] of Object.entries(systemMessage.sections)) {
        if (!override) continue;

        if (typeof override.action === "function") {
            transformCallbacks.set(sectionId, override.action);
            wireSections[sectionId] = { action: "transform" };
        } else {
            wireSections[sectionId] = { action: override.action, content: override.content };
        }
    }

    if (transformCallbacks.size === 0) {
        return { wirePayload: systemMessage, transformCallbacks: undefined };
    }

    const wirePayload: SystemMessageCustomizeConfig = {
        ...systemMessage,
        sections: wireSections as SystemMessageCustomizeConfig["sections"],
    };

    return { wirePayload, transformCallbacks };
}

function getNodeExecPath(): string {
    if (process.versions.bun) {