Add resolveNode param which allows data to be used for edges, not just nodes

Author: mzikherman

src/connection/__tests__/arrayconnection.js

@@ -868,6 +868,53 @@ describe('connectionFromArraySlice()', () => {
       }
     });
   });
+
+  it('can populate edges and resolve nodes from the array', () => {
+    const letterEdgeData = [
+      {
+        letter: 'A',
+        isFirst: true,
+      },
+      {
+        letter: 'B',
+        isFirst: false,
+      }
+    ];
+
+    const c = connectionFromArraySlice(
+      letterEdgeData,
+      {
+        first: 2,
+      },
+      {
+        sliceStart: 0,
+        arrayLength: 2,
+        resolveNode: ({ letter }) => letter,
+      }
+    );
+    return expect(c).to.deep.equal({
+      edges: [
+        {
+          isFirst: true,
+          node: 'A',
+          letter: 'A',
+          cursor: 'YXJyYXljb25uZWN0aW9uOjA=',
+        },
+        {
+          isFirst: false,
+          node: 'B',
+          letter: 'B',
+          cursor: 'YXJyYXljb25uZWN0aW9uOjE=',
+        },
+      ],
+      pageInfo: {
+        startCursor: 'YXJyYXljb25uZWN0aW9uOjA=',
+        endCursor: 'YXJyYXljb25uZWN0aW9uOjE=',
+        hasPreviousPage: false,
+        hasNextPage: false,
+      }
+    });
+  });
 });
 
 describe('connectionFromPromisedArraySlice()', () => {

src/connection/arrayconnection.js

@@ -21,6 +21,7 @@ import {
 type ArraySliceMetaInfo = {
   sliceStart: number;
   arrayLength: number;
+  resolveNode?: (edge: any) => {};
 };
 
 /**
@@ -68,7 +69,7 @@ export function connectionFromArraySlice<T>(
   meta: ArraySliceMetaInfo
 ): Connection<T> {
   const { after, before, first, last } = args;
-  const { sliceStart, arrayLength } = meta;
+  const { sliceStart, arrayLength, resolveNode } = meta;
   const sliceEnd = sliceStart + arraySlice.length;
   const beforeOffset = getOffsetWithDefault(before, arrayLength);
   const afterOffset = getOffsetWithDefault(after, -1);
@@ -110,10 +111,17 @@ export function connectionFromArraySlice<T>(
     arraySlice.length - (sliceEnd - endOffset)
   );
 
-  const edges = slice.map((value, index) => ({
-    cursor: offsetToCursor(startOffset + index),
-    node: value,
-  }));
+  const edges = slice.map((value, index) => {
+    const newEdge = {
+      cursor: offsetToCursor(startOffset + index),
+      node: resolveNode ? resolveNode(value) : value,
+    };
+
+    if (resolveNode) {
+      return { ...newEdge, ...value };
+    }
+    return newEdge;
+  });
 
   const firstEdge = edges[0];
   const lastEdge = edges[edges.length - 1];