Simple slack alerts

slackAlerts.ts

import type { Result } from "true-myth";

export function newSlackAlertInterceptor(args: {
	slackWebhookUrl: string;
	environment: string;
	appName: string;
	logsUrl: string;
}) {
	const { slackWebhookUrl, environment, appName, logsUrl } = args;
	const baseParams = {
		slackWebhookUrl,
		type: "error",
		serviceName: appName,
		environment,
		logsUrl,
	} as const;

	return {
		withSlackAlertOnErr: async <T, E>(f: () => Promise<Result<T, E>>): Promise<Result<T, E>> => {
			try {
				const r = await f();
				if (r.isErr) {
					await sendSlackAlert({
						...baseParams,
						errorDetails: r.error,
					});
				}

				return r;
			} catch (exception) {
				await sendSlackAlert({
					...baseParams,
					errorDetails: exception,
				});
				throw exception;
			}
		},
	};
}

async function sendSlackAlert(args: {
	slackWebhookUrl: string;
	type: "error" | "warn";
	serviceName: string;
	environment: string;
	logsUrl: string;
	errorDetails: unknown;
}): Promise<void> {
	const { slackWebhookUrl, type, serviceName, environment, errorDetails, logsUrl } = args;

	const emoji = type === "error" ? ":rotating_light:" : ":warning:";
	const title = type === "error" ? "Error received" : "Warning received";
	const errorJson = JSON.stringify(errorDetails, null, 2);
	const payload = {
		blocks: [
			{
				type: "header",
				text: {
					type: "plain_text",
					text: `${emoji} ${environment === "dev" ? "[dev]" : ""} ${title}`,
					emoji: true,
				},
			},
			{
				type: "section",
				fields: [
					{
						type: "mrkdwn",
						text: `*Service:* ${serviceName}`,
					},
					{
						type: "mrkdwn",
						text: `*Environment:* ${environment}`,
					},
				],
			},
			{
				type: "section",
				text: {
					type: "mrkdwn",
					text: "*Details:*\n```" + errorJson + "```",
				},
			},
			{
				type: "section",
				text: {
					type: "mrkdwn",
					text: `:link: <${logsUrl}|View logs>`,
				},
			},
		],
	};

	try {
		const response = await fetch(slackWebhookUrl, {
			method: "POST",
			headers: { "Content-Type": "application/json" },
			body: JSON.stringify(payload),
		});
		if (!response.ok) {
			console.error(`Slack webhook call failed: ${response.status} ${response.statusText}`);
		}
	} catch (error) {
		console.error("Slack webhook call error:", error);
	}
}