[Bug fix] Make pagination work with deletes

convex/pagination.test.ts

@@ -55,3 +55,158 @@ test("paginate", async () => {
   expect(page3).toMatchObject([]);
   expect(isDone3).toEqual(true);
 });
+
+test("paginate with deletes", async () => {
+  const t = convexTest(schema);
+  await t.run(async (ctx) => {
+    await ctx.db.insert("messages", { author: "sarah", body: "hello1" });
+    await ctx.db.insert("messages", { author: "michal", body: "boo" });
+    await ctx.db.insert("messages", { author: "sarah", body: "hello2" });
+    await ctx.db.insert("messages", { author: "sarah", body: "hello3" });
+    await ctx.db.insert("messages", { author: "sarah", body: "hello4" });
+    await ctx.db.insert("messages", { author: "michal", body: "boing" });
+    await ctx.db.insert("messages", { author: "sarah", body: "hello5" });
+  });
+  const { continueCursor, isDone, page } = await t.query(api.pagination.list, {
+    author: "sarah",
+    paginationOptions: {
+      cursor: null,
+      numItems: 2,
+    },
+  });
+  expect(page).toMatchObject([
+    { author: "sarah", body: "hello1" },
+    { author: "sarah", body: "hello2" },
+  ]);
+  expect(isDone).toEqual(false);
+  await t.run(async (ctx) => {
+    await ctx.db.delete(page[1]._id);
+  });
+  const { isDone: isDone2, page: page2 } = await t.query(api.pagination.list, {
+    author: "sarah",
+    paginationOptions: {
+      cursor: continueCursor,
+      numItems: 4,
+    },
+  });
+  expect(page2).toMatchObject([
+    { author: "sarah", body: "hello3" },
+    { author: "sarah", body: "hello4" },
+    { author: "sarah", body: "hello5" },
+  ]);
+  expect(isDone2).toEqual(true);
+});
+
+test("paginate with deletes and indexes", async () => {
+  const t = convexTest(schema);
+  await t.run(async (ctx) => {
+    await ctx.db.insert("messages", { author: "sarah", body: "hello1" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello1" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello2" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello3" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello4" });
+  });
+  const { continueCursor, isDone, page } = await t.query(
+    api.pagination.listWithIndex,
+    {
+      author: "jordan",
+      paginationOptions: {
+        cursor: null,
+        numItems: 1,
+      },
+    },
+  );
+  expect(page).toMatchObject([{ author: "jordan", body: "hello1" }]);
+  expect(isDone).toEqual(false);
+  await t.run(async (ctx) => {
+    await ctx.db.delete(page[0]._id);
+  });
+  const {
+    isDone: isDone2,
+    page: page2,
+    continueCursor: continueCursor2,
+  } = await t.query(api.pagination.listWithIndex, {
+    author: "jordan",
+    paginationOptions: {
+      cursor: continueCursor,
+      numItems: 2,
+    },
+  });
+  expect(page2).toMatchObject([
+    { author: "jordan", body: "hello2" },
+    { author: "jordan", body: "hello3" },
+  ]);
+  expect(isDone2).toEqual(false);
+  await t.run(async (ctx) => {
+    await ctx.db.delete(page2[1]._id);
+  });
+  const { isDone: isDone3, page: page3 } = await t.query(
+    api.pagination.listWithIndex,
+    {
+      author: "jordan",
+      paginationOptions: {
+        cursor: continueCursor2,
+        numItems: 1,
+      },
+    },
+  );
+  expect(page3).toMatchObject([{ author: "jordan", body: "hello4" }]);
+  expect(isDone3).toEqual(true);
+});
+
+test("paginate with deletes and composite index", async () => {
+  const t = convexTest(schema);
+  await t.run(async (ctx) => {
+    await ctx.db.insert("messages", { author: "sarah", body: "hello1" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello2" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello4" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello3" });
+    await ctx.db.insert("messages", { author: "jordan", body: "hello1" });
+  });
+  const { continueCursor, isDone, page } = await t.query(
+    api.pagination.listWithCompositeIndex,
+    {
+      author: "jordan",
+      paginationOptions: {
+        cursor: null,
+        numItems: 1,
+      },
+    },
+  );
+  expect(page).toMatchObject([{ author: "jordan", body: "hello1" }]);
+  expect(isDone).toEqual(false);
+  await t.run(async (ctx) => {
+    await ctx.db.delete(page[0]._id);
+  });
+  const {
+    isDone: isDone2,
+    page: page2,
+    continueCursor: continueCursor2,
+  } = await t.query(api.pagination.listWithCompositeIndex, {
+    author: "jordan",
+    paginationOptions: {
+      cursor: continueCursor,
+      numItems: 2,
+    },
+  });
+  expect(page2).toMatchObject([
+    { author: "jordan", body: "hello2" },
+    { author: "jordan", body: "hello3" },
+  ]);
+  expect(isDone2).toEqual(false);
+  await t.run(async (ctx) => {
+    await ctx.db.delete(page2[1]._id);
+  });
+  const { isDone: isDone3, page: page3 } = await t.query(
+    api.pagination.listWithCompositeIndex,
+    {
+      author: "jordan",
+      paginationOptions: {
+        cursor: continueCursor2,
+        numItems: 1,
+      },
+    },
+  );
+  expect(page3).toMatchObject([{ author: "jordan", body: "hello4" }]);
+  expect(isDone3).toEqual(true);
+});

convex/pagination.ts

@@ -16,3 +16,29 @@ export const list = query({
       .paginate(args.paginationOptions);
   },
 });
+
+export const listWithIndex = query({
+  args: {
+    author: v.string(),
+    paginationOptions: paginationOptsValidator,
+  },
+  handler: async (ctx, args) => {
+    return await ctx.db
+      .query("messages")
+      .withIndex("author", (q) => q.eq("author", args.author))
+      .paginate(args.paginationOptions);
+  },
+});
+
+export const listWithCompositeIndex = query({
+  args: {
+    author: v.string(),
+    paginationOptions: paginationOptsValidator,
+  },
+  handler: async (ctx, args) => {
+    return await ctx.db
+      .query("messages")
+      .withIndex("author_body", (q) => q.eq("author", args.author))
+      .paginate(args.paginationOptions);
+  },
+});

convex/schema.ts

@@ -9,6 +9,7 @@ export default defineSchema({
     score: v.optional(v.number()),
   })
     .index("author", ["author"])
+    .index("author_body", ["author", "body"])
     .searchIndex("body", {
       searchField: "body",
       filterFields: ["author"],