config-cache.ts

import { mkdirSync, readFileSync, rmSync, writeFileSync } from "fs";
import * as path from "path";
import { findUpSync } from "find-up";
import { CI } from "./is-ci";
import isInteractive from "./is-interactive";
import { logger } from "./logger";

let cacheMessageShown = false;

let __cacheFolder: string | null | undefined;
function getCacheFolder() {
	if (__cacheFolder || __cacheFolder === null) return __cacheFolder;

	const closestNodeModulesDirectory = findUpSync("node_modules", {
		type: "directory",
	});
	__cacheFolder = closestNodeModulesDirectory
		? path.join(closestNodeModulesDirectory, ".cache/wrangler")
		: null;

	if (!__cacheFolder) {
		logger.debug("No folder available to cache configuration");
	}
	return __cacheFolder;
}

const arrayFormatter = new Intl.ListFormat("en", {
	style: "long",
	type: "conjunction",
});

function showCacheMessage(fields: string[], folder: string) {
	if (!cacheMessageShown && isInteractive() && !CI.isCI()) {
		if (fields.length > 0) {
			logger.debug(
				`Retrieving cached values for ${arrayFormatter.format(
					fields
				)} from ${path.relative(process.cwd(), folder)}`
			);
			cacheMessageShown = true;
		}
	}
}

export function getConfigCache<T>(fileName: string): Partial<T> {
	try {
		const cacheFolder = getCacheFolder();
		if (cacheFolder) {
			const configCacheLocation = path.join(cacheFolder, fileName);
			const configCache = JSON.parse(
				readFileSync(configCacheLocation, "utf-8")
			);
			showCacheMessage(Object.keys(configCache), cacheFolder);
			return configCache;
		} else return {};
	} catch (err) {
		return {};
	}
}

export function saveToConfigCache<T>(
	fileName: string,
	newValues: Partial<T>
): void {
	const cacheFolder = getCacheFolder();
	if (cacheFolder) {
		logger.debug(`Saving to cache: ${JSON.stringify(newValues)}`);
		const configCacheLocation = path.join(cacheFolder, fileName);
		const existingValues = getConfigCache(fileName);

		mkdirSync(path.dirname(configCacheLocation), { recursive: true });
		writeFileSync(
			configCacheLocation,
			JSON.stringify({ ...existingValues, ...newValues }, null, 2)
		);
	}
}

export function purgeConfigCaches() {
	const cacheFolder = getCacheFolder();
	if (cacheFolder) {
		rmSync(cacheFolder, { recursive: true, force: true });
	}
	__cacheFolder = undefined;
}