refactor(effect): add request body schema decoders to api routes

2 files changed, 71 insertions, 0 deletions

diff --git a/src/lib/Effect/requestBody.test.ts b/src/lib/Effect/requestBody.test.ts
new file mode 100644
index 00000000..8ca31036
--- /dev/null
+++ b/src/lib/Effect/requestBody.test.ts
@@ -0,0 +1,56 @@
+import { describe, expect, it } from "vitest";
+import { Schema } from "effect";
+import {
+	decodeRequestJsonOrThrow,
+	decodeUnknownOrThrow,
+} from "$lib/Effect/requestBody";
+
+describe("request body effect decoders", () => {
+	it("decodes unknown payload with a schema", () => {
+		const decoded = decodeUnknownOrThrow(Schema.Array(Schema.String), [
+			"a",
+			"b",
+			"c",
+		]);
+
+		expect(decoded).toEqual(["a", "b", "c"]);
+	});
+
+	it("throws when payload does not match schema", () => {
+		expect(() =>
+			decodeUnknownOrThrow(Schema.Array(Schema.String), ["a", 2]),
+		).toThrowError();
+	});
+
+	it("decodes request.json body with schema", async () => {
+		const request = new Request("https://due.moe/api/preferences", {
+			method: "PUT",
+			headers: {
+				"content-type": "application/json",
+			},
+			body: JSON.stringify(["seasonal", "ongoing"]),
+		});
+		const decoded = await decodeRequestJsonOrThrow(
+			request,
+			Schema.Array(Schema.String),
+		);
+
+		expect(decoded).toEqual(["seasonal", "ongoing"]);
+	});
+
+	it("decodes request.json object body with record schema", async () => {
+		const request = new Request("https://due.moe/api/configuration", {
+			method: "PUT",
+			headers: {
+				"content-type": "application/json",
+			},
+			body: JSON.stringify({ theme: "dark", notifications: true }),
+		});
+		const decoded = await decodeRequestJsonOrThrow(
+			request,
+			Schema.Record(Schema.String, Schema.Unknown),
+		);
+
+		expect(decoded).toEqual({ theme: "dark", notifications: true });
+	});
+});
diff --git a/src/lib/Effect/requestBody.ts b/src/lib/Effect/requestBody.ts
new file mode 100644
index 00000000..c43c30b2
--- /dev/null
+++ b/src/lib/Effect/requestBody.ts
@@ -0,0 +1,15 @@
+import { Schema } from "effect";
+
+type SyncDecodingSchema = Schema.Top & {
+	readonly DecodingServices: never;
+};
+
+export const decodeUnknownOrThrow = <S extends SyncDecodingSchema>(
+	schema: S,
+	input: unknown,
+): S["Type"] => Schema.decodeUnknownSync(schema)(input);
+
+export const decodeRequestJsonOrThrow = async <S extends SyncDecodingSchema>(
+	request: Request,
+	schema: S,
+): Promise<S["Type"]> => decodeUnknownOrThrow(schema, await request.json());