Method handlePostMessage

src/server/sse.ts:137–190

* Handles incoming POST messages. * * This should be called when a POST request is made to send a message to the server.

(req: IncomingMessage & { auth?: AuthInfo }, res: ServerResponse, parsedBody?: unknown)

     * This should be called when a POST request is made to send a message to the server.
     */
    async handlePostMessage(req: IncomingMessage & { auth?: AuthInfo }, res: ServerResponse, parsedBody?: unknown): Promise<void> {
        if (!this._sseResponse) {
            const message = 'SSE connection not established';
            res.writeHead(500).end(message);
            throw new Error(message);
        }

        // Validate request headers for DNS rebinding protection
        const validationError = this.validateRequestHeaders(req);
        if (validationError) {
            res.writeHead(403).end(validationError);
            this.onerror?.(new Error(validationError));
            return;
        }

        const authInfo: AuthInfo | undefined = req.auth;

        const host = req.headers.host;
        const protocol = req.socket instanceof TLSSocket ? 'https' : 'http';
        const fullUrl = host && req.url ? new URL(req.url, `${protocol}://${host}`) : undefined;

        const requestInfo: RequestInfo = {
            headers: req.headers,
            url: fullUrl
        };

        let body: string | unknown;
        try {
            const ct = contentType.parse(req.headers['content-type'] ?? '');
            if (ct.type !== 'application/json') {
                throw new Error(`Unsupported content-type: ${ct.type}`);
            }

            body =
                parsedBody ??
                (await getRawBody(req, {
                    limit: MAXIMUM_MESSAGE_SIZE,
                    encoding: ct.parameters.charset ?? 'utf-8'
                }));
        } catch (error) {
            res.writeHead(400).end(String(error));
            this.onerror?.(error as Error);
            return;
        }

        try {
            await this.handleMessage(typeof body === 'string' ? JSON.parse(body) : body, { requestInfo, authInfo });
        } catch {
            res.writeHead(400).end(`Invalid message: ${body}`);
            return;
        }

        res.writeHead(202).end('Accepted');
    }

    /**
     * Handle a client message, regardless of how it arrived. This can be used to inform the server of messages that arrive via a means different than HTTP POST.