Merge pull request #9 from mindler-sasu/main

add support for tuples in attributes
woltsu · Mar 16, 2024 · b6cb471 · b6cb471
2 parents d447cf4 + 20e8145
commit b6cb471
Show file tree

Hide file tree

Showing 3 changed files with 43 additions and 7 deletions.
diff --git a/src/queryBuilders/getItemQueryBuilder.integration.test.ts b/src/queryBuilders/getItemQueryBuilder.integration.test.ts
@@ -76,7 +76,7 @@ describe("GetItemQueryBuilder", () => {
     expect(Object.keys(data!).length).toBe(2);
   });
 
-  it("handles selecting attributes from arrays and tuples", async () => {
+  it("handles selecting attributes from arrays", async () => {
     const data = await tsynamoClient
       .getItemFrom("myOtherTable")
       .keys({
@@ -91,6 +91,20 @@ describe("GetItemQueryBuilder", () => {
     expect(data?.cats?.length).toEqual(1);
     expect(data?.cats?.[0].age).toEqual(TEST_DATA[6].cats[1].age);
   });
+  it("handles selecting attributes from tuples", async () => {
+    const data = await tsynamoClient
+      .getItemFrom("myOtherTable")
+      .keys({
+        userId: TEST_DATA[6].userId,
+        stringTimestamp: "123",
+      })
+      .consistentRead(true)
+      .attributes(["tuplez[0]"])
+      .execute();
+
+    expect(Object.keys(data!).length).toBe(1);
+    expect(data?.tuplez?.[0]).toEqual(TEST_DATA[6].tuplez[0]);
+  });
 
   it("can't await instance directly", async () => {
     expect(

diff --git a/src/typeHelpers.ts b/src/typeHelpers.ts
@@ -181,6 +181,20 @@ export type ObjectKeyPaths<T> =
     : // Leaf value reached, don't return anything
       never;
 
+type IsTuple<T> = T extends [any, ...any] ? true : false;
+
+/**
+ * Generate union from 0 to N
+ * RangeToN<3> => 0 | 1 | 2 | 3
+ */
+type RangeToN<
+  N extends number,
+  Result extends any[] = []
+> = Result["length"] extends N
+  ? Result[number]
+  : RangeToN<N, [...Result, Result["length"]]>;
+
+//     T extends (number extends T['length'] ? [] : any[])
 export type ObjectFullPaths<T> =
   // if `T` is an object or array
   T extends Record<PropertyKey, unknown>
@@ -194,10 +208,18 @@ export type ObjectFullPaths<T> =
             `${Key}` | `${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}].${ObjectFullPaths<A[][number]>}`
+          ? IsTuple<T[Key]> extends true
+            ? // If tuple create array concatenate the key, specific array accessor for each index of the tuple, and the rest of the path recursively
+              | `${Key}`
+                | `${Key}${ObjectFullPaths<{
+                    [SpecificKey in RangeToN<
+                      T[Key]["length"]
+                    > as `[${SpecificKey}]`]: T[Key][SpecificKey];
+                  }>}`
+            : // If it's an array concatenate the key, array accessors, and the rest of the path recursively
+              | `${Key}`
+                | `${Key}[${number}]`
+                | `${Key}[${number}].${ObjectFullPaths<A[][number]>}`
           : `${Key}`
         : // unreachable branch (if key is symbol)
           never

diff --git a/test/testFixture.ts b/test/testFixture.ts
@@ -28,7 +28,7 @@ export interface DDB {
     stringTimestamp: SortKey<string>;
     somethingElse: number;
     someBoolean: boolean;
-    tuple: [
+    tuplez: [
       {
         beer: string;
       },
@@ -174,7 +174,7 @@ export const TEST_DATA = [
     stringTimestamp: "123",
     somethingElse: -5,
     someBoolean: true,
-    tuple: [
+    tuplez: [
       {
         beer: "karhu",
       },