Merge pull request #7 from mindler-sasu/main

support array accessors in attribute selections

src/queryBuilders/__snapshots__/queryQueryBuilder.integration.test.ts.snap

@@ -1,5 +1,17 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
+exports[`QueryQueryBuilder > handles a FilterExpression that takes attributes from cats array 1`] = `
+[
+  {
+    "cats": [
+      {
+        "age": 42,
+      },
+    ],
+  },
+]
+`;
+
 exports[`QueryQueryBuilder > handles a FilterExpression that uses attribute_exists and attribute_not_exists 1`] = `
 [
   {

src/queryBuilders/getItemQueryBuilder.integration.test.ts

@@ -58,7 +58,7 @@ describe("GetItemQueryBuilder", () => {
     expect(Object.keys(data!).length).toBe(2);
   });
 
-  it("handles selecting nested attributes excessively deep", async () => {
+  it("handles selecting deeply nested attributes", async () => {
     const data = await tsynamoClient
       .getItemFrom("myTable")
       .keys({
@@ -76,7 +76,21 @@ describe("GetItemQueryBuilder", () => {
     expect(Object.keys(data!).length).toBe(2);
   });
 
-  it.todo("handles selecting attributes from arrays");
+  it("handles selecting attributes from arrays and tuples", async () => {
+    const data = await tsynamoClient
+      .getItemFrom("myOtherTable")
+      .keys({
+        userId: TEST_DATA[6].userId,
+        stringTimestamp: "123",
+      })
+      .consistentRead(true)
+      .attributes(["cats[1].age"])
+      .execute();
+
+    expect(Object.keys(data!).length).toBe(1);
+    expect(data?.cats?.length).toEqual(1);
+    expect(data?.cats?.[0].age).toEqual(TEST_DATA[6].cats[1].age);
+  });
 
   it("can't await instance directly", async () => {
     expect(

src/queryBuilders/queryQueryBuilder.integration.test.ts

@@ -171,4 +171,14 @@ describe("QueryQueryBuilder", () => {
 
     expect(data).toMatchSnapshot();
   });
+  it("handles a FilterExpression that takes attributes from cats array", async () => {
+    let data = await tsynamoClient
+      .query("myOtherTable")
+      .keyCondition("userId", "=", "123")
+      .filterExpression("cats", "attribute_exists")
+      .attributes(["cats[0].age"])
+      .execute();
+
+    expect(data).toMatchSnapshot();
+  });
 });

src/typeHelpers.ts

@@ -77,6 +77,9 @@ type RecursiveSelectAttributes<Table, Properties> = Properties extends [
 ]
   ? First extends keyof Table
     ? { [key in First]: RecursiveSelectAttributes<Table[First], Rest> }
+    : // When "First" in path is a number, and Table is an Array, Recurse to the inner type of the array
+    [First, Table] extends [`${number}`, any[]]
+    ? RecursiveSelectAttributes<As<Table, any[]>[number], Rest>[]
     : never
   : Table;
 
@@ -179,14 +182,23 @@ export type ObjectKeyPaths<T> =
       never;
 
 export type ObjectFullPaths<T> =
-  // if `T` is an object
+  // if `T` is an object or array
   T extends Record<PropertyKey, unknown>
     ? // Assign the union `keyof T` to a variable `Key`
       keyof T extends infer Key
       ? // Loop over union of keys
         Key extends string | number
-        ? // Check if the current key is an object, if it is, concatenate the key and rest of the path recursively
-          `${Key}` | `${Key}.${ObjectKeyPaths<T[Key]>}`
+        ? // Check if the current key is an object
+          T[Key] extends Record<PropertyKey, unknown>
+          ? // If it's an object, concatenate the key and rest of the path recursively
+            `${Key}` | `${Key}.${ObjectFullPaths<T[Key]>}`
+          : // If it's not an object, check if its an array
+          T[Key] extends (infer A)[]
+          ? // If it's an array concatenate the key, array accessors, and the rest of the path recursively
+            | `${Key}`
+              | `${Key}[${number}]`
+              | `${Key}[${number}].${ObjectFullPaths<A[][number]>}`
+          : `${Key}`
         : // unreachable branch (if key is symbol)
           never
       : // unreachable branch (`extends infer` is always truthy), but needs to be here for syntax

test/testFixture.ts

@@ -28,6 +28,18 @@ export interface DDB {
     stringTimestamp: SortKey<string>;
     somethingElse: number;
     someBoolean: boolean;
+    tuple: [
+      {
+        beer: string;
+      },
+      {
+        bar: string;
+      }
+    ];
+    cats: {
+      name: string;
+      age: number;
+    }[];
   };
 }
 
@@ -162,6 +174,24 @@ export const TEST_DATA = [
     stringTimestamp: "123",
     somethingElse: -5,
     someBoolean: true,
+    tuple: [
+      {
+        beer: "karhu",
+      },
+      {
+        bar: "oljenkorsi",
+      },
+    ],
+    cats: [
+      {
+        name: "Pekka Töpöhäntä",
+        age: 42,
+      },
+      {
+        name: "Sylvester J. Pussycat Sr.",
+        age: 78,
+      },
+    ],
   },
   {
     userId: "123",