Express layers

src/Layers/express/ExpressApp.ts

@@ -0,0 +1,19 @@
+import { Config, Context, Effect, Layer } from "effect"
+import type { Express } from "express"
+
+
+export class ExpressApp extends Context.Tag("ExpressApp")<ExpressApp, Express>() {}
+
+
+const importExpress = Effect.tryPromise({
+    try: () => import("express"),
+    catch: cause => new Error("Could not import 'express'. Make sure it is installed.", { cause }),
+})
+
+export const ExpressAppLive = (config: {
+    readonly trustProxy?: Config.Config<boolean>
+}) => Layer.effect(ExpressApp, Effect.gen(function*() {
+    const app = (yield* importExpress).default()
+    app.set("trust proxy", yield* config.trustProxy || Config.succeed(false))
+    return app
+}))