fix memo appearing in recommendation list if they are not matched

Author: aster-void

server/src/functions/engines/recommendation.test.ts

@@ -9,13 +9,13 @@ beforeAll(() => {
 test("recommendation engine", async () => {
   const usersFor101 = await recommendedTo(101, 5, 0);
   if (!usersFor101.ok) throw new Error();
-  expect(usersFor101.value.map((entry) => entry.u.id)).toEqual([102, 103, 0]);
+  expect(usersFor101.value.map((entry) => entry.u.id)).toEqual([102, 103]);
 
   const usersFor102 = await recommendedTo(102, 5, 0);
   if (!usersFor102.ok) throw new Error();
-  expect(usersFor102.value.map((entry) => entry.u.id)).toEqual([103, 101, 0]);
+  expect(usersFor102.value.map((entry) => entry.u.id)).toEqual([103, 101]);
 
   const usersFor103 = await recommendedTo(103, 5, 0);
   if (!usersFor103.ok) throw new Error();
-  expect(usersFor103.value.map((entry) => entry.u.id)).toEqual([102, 101, 0]);
+  expect(usersFor103.value.map((entry) => entry.u.id)).toEqual([102, 101]);
 });

server/src/functions/engines/recommendation.ts

@@ -19,14 +19,16 @@ export async function recommendedTo(
   try {
     const result = await prisma.$queryRawTyped(sql(user, limit, offset));
     return Promise.all(
-      result.map(async (res) => {
-        const user = await getUserByID(res.id);
-        if (!user.ok) throw new Error("not found"); // this shouldn't happen
-        return {
-          count: Number.parseInt(res.overlap?.toString() ?? "0"),
-          u: user.value,
-        };
-      }),
+      result
+        .filter((res) => res.id !== 0) // memo shouldn't appear in recommendation list, even if they are not matched
+        .map(async (res) => {
+          const user = await getUserByID(res.id);
+          if (!user.ok) throw new Error("not found"); // this shouldn't happen
+          return {
+            count: Number.parseInt(res.overlap?.toString() ?? "0"),
+            u: user.value,
+          };
+        }),
     )
       .then((val) => Ok(val))
       .catch((err) => Err(err));