Completing REST endpoints for GET all and POST

app/api/listings/route.ts

@@ -0,0 +1,97 @@
+import { NextResponse } from "next/server";
+import { connectToDatabase } from "@/lib/mongoose";
+import { z } from "zod";
+import Listing from "@/models/Listing";
+
+// test comment
+// ask about whether users should provide _id, that seems more like a
+// server task, the rest they should be able to
+const listingValidationSchema = z.object({
+  _id: z.string().min(1),
+  itemId: z.string().min(1),
+  labId: z.string().min(1),
+  quantityAvailable: z.number().min(0), // can list items with 0 quantity?
+  createdAt: z
+    .string()
+    // could possibly change to MM-DD-YYYY
+    .regex(/^\d{4}-\d{2}-\d{2}$/, "Invalid date format. Expected YYYY-MM-DD."),
+});
+
+async function connect() {
+  try {
+    await connectToDatabase();
+  } catch {
+    return NextResponse.json(
+      { success: false, message: "Error connecting to database" },
+      { status: 500 }
+    );
+  }
+}
+
+// get all
+async function GET() {
+  const connectionResponse = await connect();
+  if (connectionResponse) return connectionResponse;
+
+  try {
+    const listings = await Listing.find();
+    return NextResponse.json(
+      { success: true, data: listings },
+      { status: 200 }
+    );
+  } catch (error) {
+    return NextResponse.json(
+      { success: false, message: "Error occurred while retrieving listings." },
+      { status: 500 }
+    );
+  }
+}
+
+// post all
+async function POST(request: Request) {
+  const connectionResponse = await connect();
+  if (connectionResponse) return connectionResponse;
+
+  // assuming frontend sends req with content-type set to app/json
+  // content type automatically set as app/json
+  const body = await request.json();
+  const parsedBody = listingValidationSchema.safeParse(body);
+
+  if (!parsedBody.success) {
+    return NextResponse.json(
+      {
+        success: false,
+        message: "Invalid request body.",
+        // error: parsedBody.error.format(), don't expose error?
+      },
+      { status: 400 }
+    );
+  }
+
+  try {
+    const listing = await Listing.create(parsedBody.data);
+    return NextResponse.json(
+      {
+        success: true,
+        message: "Successfully created new listing.",
+        data: listing,
+      },
+      { status: 201, headers: { Location: `/app/listings/${listing._id}` } }
+      // resource will be retrievable at this url
+    );
+  } catch (error: any) {
+    if (error.code === 11000) {
+      return NextResponse.json(
+        // don't send mongo's error - exposes design info
+        { success: false, message: "This listing already exists." },
+        { status: 409 }
+      );
+    }
+    return NextResponse.json(
+      { success: false, message: "Error occurred while creating new listing." },
+      { status: 500 }
+    );
+  }
+}
+
+export { GET, POST };

models/Listing.ts

@@ -23,5 +23,5 @@ listingSchema.index(
   { unique: true }
 );
 
-const listing = mongoose.models.Listing || model("Listing", listingSchema);
-export default listing;
+const Listing = mongoose.models.Listing || model("Listing", listingSchema);
+export default Listing;