Refactor Hono API handler, fix missing headers

.vscode/settings.json

@@ -1,6 +1,6 @@
 {
-	"typescript.tsdk": "node_modules/typescript/lib",
+	"js/ts.tsdk.path": "node_modules/typescript/lib",
-	"typescript.preferences.autoImportFileExcludePatterns": [
+	"js/ts.preferences.autoImportFileExcludePatterns": [
 		"@radix-ui",
 	],
 }

packages/backend/src/api.ts

@@ -1,26 +1,55 @@
 import { registerEncoder } from "cbor2/encoder";
 import * as Api from "common/Api";
+import * as Body from "common/Body";
 import * as Cbor from "common/Cbor";
-import * as Client from "common/Client";
+import { Cause, Console, Effect, Either, HashMap, Inspectable, Option, ParseResult, pipe, Schema } from "effect";
-import { Cause, Effect, Either, HashMap, Inspectable, Option, pipe } from "effect";
 import type { HonoRequest } from "hono";
+import type { ContentfulStatusCode, StatusCode } from "hono/utils/http-status";
 
 registerEncoder(Buffer, (buffer) => [NaN, new Uint8Array(buffer.buffer, buffer.byteOffset, buffer.byteLength)]);
 
+export type ResponseData<Status extends StatusCode> =
+	| EmptyResponseData<Status>
+	| (Status extends ContentfulStatusCode ? BodyResponseData<Status> : never)
+	;
+
+export namespace ResponseData {
+	export type Any = ResponseData<StatusCode>;
+}
+
+export interface EmptyResponseData<Status extends StatusCode> {
+	readonly body: null;
+	readonly status: Status;
+}
+
+export const emptyResponse = <Status extends StatusCode>(status: Status): EmptyResponseData<Status> => Object.freeze<EmptyResponseData<Status>>({
+	body: null,
+	status,
+});
+
+export interface BodyResponseData<Status extends ContentfulStatusCode> {
+	readonly body: Uint8Array<ArrayBuffer>;
+	readonly status: Status;
+}
+
+export const bodyResponse = <Status extends ContentfulStatusCode>(status: Status) => (body: Uint8Array<ArrayBuffer>): BodyResponseData<Status> => Object.freeze<BodyResponseData<Status>>({
+	body,
+	status,
+});
+
 /* NOTE We shouldn't need to extract this to a separate type, but if we don't do
  * it the TypeScript parser in VS Code sort of blows up and the syntax colors
  * turn wrong.
  */
-type Return<Impl extends Api.ApiBundleImpl<any>> = Effect.Effect<Response, never, Effect.Effect.Context<ReturnType<Impl[keyof Impl]>>>;
+type Return<Impl extends Api.ApiBundleImpl<any>> = Effect.Effect<ResponseData.Any, never, Effect.Effect.Context<ReturnType<Impl[keyof Impl]>>>;
 
-const catchToResponse = Effect.catchAll((error: unknown) => pipe(
+const catchToResponseData = Effect.catchAll((error: unknown) => pipe(
 	error,
 	Inspectable.toJSON,
 	Cbor.encode,
-	Effect.map(Client.cborBody),
 	Effect.matchEffect({
-		onSuccess: ({ body, headers }) => Effect.fail(new Response(body, { status: 500, headers })),
+		onSuccess: (body) => Effect.fail<ResponseData.Any>(bodyResponse(500)(body)),
-		onFailure: () => Effect.fail(new Response(null, { status: 500 })),
+		onFailure: () => Effect.fail<ResponseData.Any>(RESPONSE_DATA_UNRECOVERABLE_ERROR),
 	}),
 ));
 
@@ -32,26 +61,26 @@ export const implement = <
 	impl: Impl,
 ): (request: HonoRequest<"/api/:key">) => Return<Impl> => {
 	return (honoRequest) => {
-		/* Force both return types to be `Response`. We can use the error route
+		/* Force both return types to be `ResponseData`. We can use the error
-		 * for it's short-circuit capabilities.
+		 * route for it's short-circuit capabilities.
 		 */
-		const effect: Effect.Effect<Response, Response, any> = Effect.gen(function* () {
+		const effect: Effect.Effect<ResponseData.Any, ResponseData.Any, any> = Effect.gen(function* () {
 			const key = honoRequest.param("key");
 			const maybeApi = HashMap.get(bundle.map, key);
 			if (Option.isNone(maybeApi)) {
-				return RESPONSE_API_NOT_FOUND;
+				return RESPONSE_DATA_API_NOT_FOUND;
 			}
 			const { value: api } = maybeApi;
 
 			const fn = impl[key];
 			if (fn === undefined) {
-				return RESPONSE_API_NOT_IMPLEMENTED;
+				return RESPONSE_DATA_API_NOT_IMPLEMENTED;
 			}
 
 			const request = yield* pipe(
 				honoRequest as { bytes(): Promise<Uint8Array<ArrayBuffer>> },
-				Client.decodeBody(api.request),
+				decodeBody(api.request),
-				catchToResponse,
+				catchToResponseData,
 			);
 
 			const result = yield* pipe(
@@ -61,51 +90,72 @@ export const implement = <
 				Effect.either,
 			);
 
-			const { status, response } = pipe(
+			const response = yield* pipe(
 				result,
 				Either.match({
 					onLeft: (cause) => pipe(
 						cause,
 						Cause.failureOrCause,
 						Either.match({
-							onLeft: (error) => ({
+							onLeft: (body) => pipe(
-								status: 400,
+								body,
-								response: pipe(
+								encodeBody(api.error, 400),
-									error,
+								catchToResponseData,
-									Client.encodeBody(api.error),
-									catchToResponse,
 							),
-							}),
+							onRight: (die) => pipe(
-							onRight: (die) => ({
-								status: 500,
-								response: pipe(
 								die,
 								Inspectable.toJSON,
 								Cbor.encode,
-									Effect.map(Client.cborBody),
+								Effect.map(bodyResponse(500)),
-									catchToResponse,
+								catchToResponseData,
 							),
 						}),
-						}),
 					),
-					onRight: (response) => ({
+					onRight: (body) => pipe(
-						status: 200,
+						body,
-						response: pipe(
+						encodeBody(api.response, 200),
-							response,
+						catchToResponseData,
-							Client.encodeBody(api.response),
-							catchToResponse,
 					),
 				}),
-				}),
 			);
 
-			const { body, headers } = yield* response;
+			return response;
-			return new Response(body, { status, headers });
 		});
 
 		return Effect.catchAll(effect, Effect.succeed);
 	};
 };
 
-const RESPONSE_API_NOT_FOUND = new Response(null, { status: 404 });
+const RESPONSE_DATA_API_NOT_FOUND = emptyResponse(404);
-const RESPONSE_API_NOT_IMPLEMENTED = new Response(null, { status: 501 });
+const RESPONSE_DATA_API_NOT_IMPLEMENTED = emptyResponse(501);
+const RESPONSE_DATA_UNRECOVERABLE_ERROR = emptyResponse(500);
+
+export const decodeBody = <A>(schema: Schema.Schema<A, any>) => {
+	const decoder = Schema.decodeUnknown(schema);
+	return (body: { bytes(): Promise<Uint8Array<ArrayBuffer>> }) => pipe(
+		body,
+		Body.bytes,
+		Effect.flatMap((bytes) => bytes.byteLength > 0 ? Option.some(bytes) : Option.none()),
+		Effect.flatMap(Cbor.decode),
+		Effect.catchTag("NoSuchElementException", () => Effect.succeed(undefined)),
+		Effect.flatMap(decoder),
+		Effect.tapErrorTag("ParseError", (error) => pipe(
+			error,
+			ParseResult.TreeFormatter.formatError,
+			Effect.flatMap(Console.error),
+		)),
+	);
+};
+
+export const encodeBody = <A, Status extends ContentfulStatusCode>(schema: Schema.Schema<A, any>, status: Status) => {
+	const encoder = Cbor.encodeSchema(schema);
+	return (a: A) => pipe(
+		a,
+		Option.fromNullable,
+		Effect.transposeMapOption(encoder),
+		Effect.map(Option.match({
+			onNone: () => emptyResponse(status),
+			onSome: bodyResponse(status),
+		}))
+	);
+};

packages/backend/src/app.ts

@@ -33,17 +33,16 @@ const app = new Hono()
 		// Callback URL with query response type
 		if (code !== undefined || state !== undefined) {
 			yield* Authentication.getAndProcessIdToken(code ?? null, state ?? null);
-			return Response.redirect(config.NODE_ENV === "production" ? `https://${config.HOSTNAME}/` : "http://localhost:5173/", 303);
+			return ctx.redirect(config.NODE_ENV === "production" ? `https://${config.HOSTNAME}/` : "http://localhost:5173/", 303);
 		}
 
 		// Initial login request; redirect to identity provider
-		const res = yield* pipe(
+		const url = yield* pipe(
 			Authentication.Authentication,
 			Effect.flatMap(({ sessionId }) => Authentication.makeAuthorizationUrl(sessionId)),
-			Effect.map((url) => Response.redirect(url)),
 		);
 
-		return res;
+		return ctx.redirect(url);
 	}).pipe(
 		Effect.provide(Layer.provideMerge(Authentication.Live(ctx), databaseLayer)),
 		Effect.runPromise,
@@ -58,7 +57,7 @@ const app = new Hono()
 
 		yield* Authentication.getAndProcessIdToken(code, state);
 
-		return Response.redirect(config.NODE_ENV === "production" ? `https://${config.HOSTNAME}/` : "http://localhost:5173/", 303);
+		return ctx.redirect(config.NODE_ENV === "production" ? `https://${config.HOSTNAME}/` : "http://localhost:5173/", 303);
 	}).pipe(
 		Effect.provide(Layer.provideMerge(Authentication.Live(ctx), databaseLayer)),
 		Effect.runPromise,
@@ -87,17 +86,22 @@ const app = new Hono()
 		const authenticationLayer = Authentication.Live(ctx);
 		const layers = Layer.provideMerge(authenticationLayer, databaseLayer);
 
-		const response = await pipe(
+		const { body, status } = await pipe(
 			handle(req),
 			Effect.provide(layers),
 			Effect.runPromise,
 		);
 
 		for (const [name, value] of CORS_HEADERS) {
-			response.headers.set(name, value);
+			ctx.header(name, value);
 		}
 
-		return response;
+		if (body !== null) {
+			ctx.header("Content-Type", "application/cbor");
+			return ctx.body(body, status);
+		} else {
+			return ctx.body(body, status);
+		}
 	})
 	.use("/assets/*", serveStatic({ root: FRONTEND_ROOT }))
 	.use("*", serveStatic({ path: path.join(FRONTEND_ROOT, "index.html") }));