feat: Better support for Offset Pagination #140

lkrzyzanek · Dec 5, 2023 · 773b31f · 773b31f
1 parent a5e6686
commit 773b31f
Show file tree

Hide file tree

Showing 9 changed files with 38 additions and 17 deletions.
diff --git a/.gitignore b/.gitignore
@@ -13,6 +13,7 @@ junit.xml
 
 # Node modules
 node_modules/
+.nx
 
 # Mac OS
 .DS_Store

diff --git a/examples/in-memory/server.js b/examples/in-memory/server.js
@@ -92,7 +92,7 @@ const typeDefs = gql`
         booksByTitle(first: Int = 10 after: String title: String): BookConnection
         booksByAuthor(first: Int = 10 after: String author: String): BookConnection
 
-        booksByOffset(first: Int = 10 after: String): BookConnection
+        booksByOffset(first: Int = 10, after: String, page: Int): BookConnection
 
         booksDynamic(first: Int = 10 after: String): BookConnection
     }

diff --git a/examples/mongodb/package.json b/examples/mongodb/package.json
@@ -21,7 +21,7 @@
         "graphql": "^16.6.0",
         "graphql-tag": "2.12.6",
         "mongodb": "^5.1.0",
-        "mongodb-memory-server": "^8.12.1"
+        "mongodb-memory-server": "^9.1.1"
     },
     "devDependencies": {
         "@graphql-codegen/cli": "^3.2.2",

diff --git a/examples/mongodb/src/datasources/booksApi.ts b/examples/mongodb/src/datasources/booksApi.ts
@@ -8,6 +8,7 @@ const collectionName = "books";
 export async function createBooksDataSource(mongoDb: Db) {
     const ds = new MongoDbDataSource<BookType, ObjectId, QueryBooksArgs, QueryBooks_DescArgs>({
         collectionName,
+        //@ts-ignore
         mongoDb,
         filters: (args) => {
             const filters = [];

diff --git a/packages/core/__tests__/test-offset-ds.ts b/packages/core/__tests__/test-offset-ds.ts
@@ -33,35 +33,48 @@ describe("offset-totalCount", () => {
 });
 
 describe("offset-after", () => {
+    const array = [{"id": 1}, {"id": 2}, {"id": 3}, {"id": 4}];
 
     test("no-offset", async () => {
         const ds = new ArrayOffsetDs([{"id": 1}]);
         const offset = new OffsetDataSourceWrapper(ds);
         return expect(offset.after(undefined, 10, { first: 0 })).resolves.toStrictEqual([{"_index": 0, "id": 1}]);
     })
-    test("offset", async () => {
-        const ds = new ArrayOffsetDs([{"id": 1}, {"id": 2}, {"id": 3}, {"id": 4}]);
+    test("offset-arg-first", async () => {
+        const ds = new ArrayOffsetDs(array);
+        const offset = new OffsetDataSourceWrapper(ds);
+        return expect(offset.after(2, 1, { first: 0 })).resolves.toStrictEqual([{"_index": 3, "id": 4}]);
+    })
+    test("offset-arg-page-1", async () => {
+        const ds = new ArrayOffsetDs(array);
+        const offset = new OffsetDataSourceWrapper(ds);
+        return expect(offset.after(undefined, 2, { page: 1 })).resolves.toStrictEqual([{"_index": 0, "id": 1}, { "_index": 1, "id": 2 }]);
+    })
+    test("offset-arg-page-3", async () => {
+        const ds = new ArrayOffsetDs(array);
         const offset = new OffsetDataSourceWrapper(ds);
-        return expect(offset.after(2, 1, { first: 0 })).resolves.toStrictEqual([
-            {"_index": 3, "id": 4}
-        ]);
+        return expect(offset.after(undefined, 3, { page: 2 })).resolves.toStrictEqual([{ "_index": 2, "id": 3 }, {"_index": 3,"id": 4}]);
     })
 
 });
 
 describe("offset-before", () => {
+    const array = [{"id": 1}, {"id": 2}, {"id": 3}, {"id": 4}];
 
     test("no-offset", async () => {
         const ds = new ArrayOffsetDs([{"id": 1}]);
         const offset = new OffsetDataSourceWrapper(ds);
         return expect(offset.before(undefined, 10, { last: 0 })).resolves.toStrictEqual([{"_index": 0, "id": 1}]);
     })
-    test("offset", async () => {
-        const ds = new ArrayOffsetDs([{"id": 1}, {"id": 2}, {"id": 3}, {"id": 4}]);
+    test("offset-arg-last", async () => {
+        const ds = new ArrayOffsetDs(array);
+        const offset = new OffsetDataSourceWrapper(ds);
+        return expect(offset.before(2, 1, { last: 0 })).resolves.toStrictEqual([{"_index": 3, "id": 1}]);
+    })
+    test("offset-arg-page-1", async () => {
+        const ds = new ArrayOffsetDs(array);
         const offset = new OffsetDataSourceWrapper(ds);
-        return expect(offset.before(2, 1, { last: 0 })).resolves.toStrictEqual([
-            {"_index": 3, "id": 1},
-        ]);
+        return expect(offset.before(undefined, 3, { page: 2 })).resolves.toStrictEqual([{ "_index": 2, "id": 2 }, {"_index": 3,"id": 1}]);
     })
 
 });

diff --git a/packages/core/src/CursorPagerSpec.ts b/packages/core/src/CursorPagerSpec.ts
@@ -39,6 +39,7 @@ export interface PageInfo {
 export interface ArgsForward {
     first: number
     after?: string
+    page?: number
 }
 
 /**
@@ -48,6 +49,7 @@ export interface ArgsForward {
 export interface ArgsBackward {
     last: number,
     before?: string
+    page?: number
 }
 
 

diff --git a/packages/core/src/DataSourcePager.ts b/packages/core/src/DataSourcePager.ts
@@ -88,7 +88,8 @@ export function dataSourcePager<NodeType,
         const resultPlusOne = await ds.after(afterId, args.first + 1, args);
 
         const hasNextPage = resultPlusOne?.length > args.first;
-        const hasPreviousPage = !!args.after;
+        let hasPreviousPage = !!args.after;
+        if (args.page) hasPreviousPage = args.page > 1;
 
         let count;
         if (fetchTotalCountInResolver) count = await totalCount(args, ds);
@@ -110,7 +111,8 @@ export function dataSourcePager<NodeType,
         const resultPlusOne = await ds.before(beforeId, args.last + 1, args);
 
         const hasNextPage = resultPlusOne?.length > args.last;
-        const hasPreviousPage = !!args.before;
+        let hasPreviousPage = !!args.before;
+        if (args.page) hasPreviousPage = args.page > 1;
 
         let count;
         if (fetchTotalCountInResolver) count = await totalCount(args, ds);

diff --git a/packages/core/src/datasource/OffsetDataSourceWrapper.ts b/packages/core/src/datasource/OffsetDataSourceWrapper.ts
@@ -19,12 +19,14 @@ export class OffsetDataSourceWrapper<NodeType,
     }
 
     async after(afterIndex: number | undefined, size: number, args: ArgsForwardType): Promise<NodeType[]> {
-        const start = afterIndex != null ? afterIndex + 1 : 0;
+        let start = afterIndex != null ? afterIndex + 1 : 0;
+        start = args.page && args.page > 1 ? ((args.page - 1) * (size - 1)) : start;
         return this.ds.after(start, size, args).then(data => this.addIndexField(start, data));
     }
 
     async before(beforeIndex: number | undefined, size: number, args: ArgsBackwardType): Promise<NodeType[]> {
-        const start = beforeIndex != null ? beforeIndex + 1 : 0;
+        let start = beforeIndex != null ? beforeIndex + 1 : 0;
+        start = args.page && args.page > 1 ? ((args.page - 1) * (size - 1)) : start;
         return this.ds.before(start, size, args).then(data => this.addIndexField(start, data));
     }
 

diff --git a/packages/mongodb/package.json b/packages/mongodb/package.json
@@ -50,6 +50,6 @@
   "devDependencies": {
     "@types/node": "^18.15.11",
     "mongodb": "^5.1.0",
-    "mongodb-memory-server": "^9.0.0"
+    "mongodb-memory-server": "^9.1.1"
   }
 }