typesafe context in api server

Author: yujonglee

apps/api/package.json

@@ -7,6 +7,7 @@
     "cf-typegen": "wrangler types --env-interface CloudflareBindings"
   },
   "dependencies": {
+    "@hono/zod-validator": "^0.7.3",
     "@supabase/supabase-js": "^2.58.0",
     "@t3-oss/env-core": "^0.13.8",
     "hono": "^4.9.10",

apps/api/src/env.ts

@@ -3,7 +3,9 @@ import type { Context } from "hono";
 import { env } from "hono/adapter";
 import { z } from "zod";
 
-export const getEnv = (c: Context) =>
+import type { Env } from "./types";
+
+export const getEnv = (c: Context<Env>) =>
   createEnv({
     server: {
       PORT: z.coerce.number().default(3000),
@@ -13,6 +15,6 @@ export const getEnv = (c: Context) =>
       SUPABASE_URL: z.string().min(1),
       SUPABASE_SERVICE_ROLE_KEY: z.string().min(1),
     },
-    runtimeEnv: env(c),
+    runtimeEnv: env(c) as Record<string, string | undefined>,
     emptyStringAsUndefined: true,
   });

apps/api/src/index.ts

@@ -1,21 +1,57 @@
+import { zValidator } from "@hono/zod-validator";
 import { Hono } from "hono";
 import { proxy } from "hono/proxy";
+import { z } from "zod";
 
 import { getEnv } from "./env";
 import { supabaseMiddleware } from "./middleware/supabase";
+import type { Env } from "./types";
 
-const app = new Hono();
+const app = new Hono<Env>();
 app.use("/v1", supabaseMiddleware());
 
 app.get("/health", (c) => c.text("OK"));
 
-app.post("/v1/write", async (c) => {
-  return c.json({ message: "OK" });
-});
+app.post(
+  "/v1/write",
+  zValidator(
+    "json",
+    z.discriminatedUnion("operation", [
+      z.object({
+        table: z.string(),
+        row_id: z.string(),
+        operation: z.literal("delete"),
+      }),
+      z.object({
+        table: z.string(),
+        row_id: z.string(),
+        data: z.record(z.string(), z.unknown()),
+        operation: z.literal("update"),
+      }),
+    ]),
+  ),
+  async (c) => {
+    const supabase = c.get("supabase");
+    const user = c.get("user");
+    const body = c.req.valid("json");
+
+    // TODO: use RPC / transaction
+    if (body.operation === "delete") {
+      await supabase.from(body.table).delete().eq("id", body.row_id);
+    } else {
+      await supabase.from(body.table).upsert({
+        ...body.data,
+        id: body.row_id,
+        user_id: user.id,
+      });
+    }
+
+    return c.json({ message: "OK" });
+  },
+);
 
 app.post("/v1/chat/completions", async (c) => {
   const { OPENAI_BASE_URL, OPENAI_DEFAULT_MODEL, OPENAI_API_KEY } = getEnv(c);
-
   const data = await c.req.json();
 
   const res = await proxy(

apps/api/src/middleware/supabase.ts

@@ -2,9 +2,10 @@ import { createClient } from "@supabase/supabase-js";
 import { createMiddleware } from "hono/factory";
 
 import { getEnv } from "../env";
+import type { Env } from "../types";
 
 export const supabaseMiddleware = () => {
-  return createMiddleware(async (c, next) => {
+  return createMiddleware<Env>(async (c, next) => {
     const authHeader = c.req.header("Authorization");
     const token = authHeader?.replace("Bearer ", "");
 

apps/api/src/types.ts

@@ -0,0 +1,10 @@
+import type { SupabaseClient, User } from "@supabase/supabase-js";
+
+export type Variables = {
+  supabase: SupabaseClient;
+  user: User;
+};
+
+export type Env = {
+  Variables: Variables;
+};