Add/Fix tests

Author: naqvitalha

src/FlashListProps.ts

@@ -23,6 +23,12 @@ export interface ListRenderItemInfo<TItem> {
   extraData?: any;
 }
 
+export interface OverrideProps {
+  initialDrawBatchSize?: number;
+  // rest can be string to any
+  [key: string]: any;
+}
+
 export type RenderTarget = "Cell" | "StickyHeader" | "Measurement";
 
 export const RenderTargetOptions: Record<string, RenderTarget> = {
@@ -293,7 +299,7 @@ export interface FlashListProps<TItem>
   /**
    * For debugging and exception use cases, internal props will be overriden with these values if used
    */
-  overrideProps?: object;
+  overrideProps?: OverrideProps;
 
   /**
    * Set this when offset is needed for the loading indicator to show correctly.

src/__tests__/RecyclerView.test.tsx

@@ -33,37 +33,92 @@ jest.mock("../recyclerview/utils/measureLayout", () => {
   };
 });
 
+const renderRecyclerView = (args: {
+  numColumns?: number;
+  masonry?: boolean;
+  horizontal?: boolean;
+}) => {
+  const { numColumns = 1, masonry = false, horizontal = false } = args;
+  return render(
+    <RecyclerView
+      data={[
+        0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
+        20, 21,
+      ]}
+      masonry={masonry}
+      overrideProps={{ initialDrawBatchSize: 1 }}
+      drawDistance={0}
+      numColumns={numColumns}
+      horizontal={horizontal}
+      renderItem={({ item }) => <Text>{item}</Text>}
+    />
+  );
+};
+
 describe("RecyclerView", () => {
   beforeEach(() => {
     jest.clearAllMocks();
     jest.useFakeTimers();
   });
+  describe("Linear Layout", () => {
+    it("renders items ", () => {
+      const result = renderRecyclerView({});
+
+      expect(result).toContainReactComponent(Text, { children: 0 });
+      expect(result).not.toContainReactComponent(Text, { children: 11 });
+    });
+  });
+
+  describe("Masonry Layout", () => {
+    it("renders items with masonry", () => {
+      const result = renderRecyclerView({ masonry: true });
+
+      expect(result).toContainReactComponent(Text, { children: 0 });
+    });
+    it("should not render item 20, 21 with numColumns 2", () => {
+      const result = renderRecyclerView({ numColumns: 2, masonry: true });
+
+      expect(result).toContainReactComponent(Text, {
+        children: 17,
+      });
+      expect(result).not.toContainReactComponent(Text, {
+        children: 20,
+      });
+
+      expect(result).not.toContainReactComponent(Text, {
+        children: 21,
+      });
+    });
+  });
+
+  describe("Grid Layout", () => {
+    it("renders items with numColumns 2", () => {
+      const result = renderRecyclerView({ numColumns: 2 });
+
+      expect(result).toContainReactComponent(Text, { children: 0 });
+    });
+    it("should not render item 18, 19 with numColumns 2", () => {
+      const result = renderRecyclerView({ numColumns: 2 });
+
+      expect(result).toContainReactComponent(Text, {
+        children: 17,
+      });
+      expect(result).not.toContainReactComponent(Text, {
+        children: 20,
+      });
+
+      expect(result).not.toContainReactComponent(Text, {
+        children: 21,
+      });
+    });
+  });
 
-  it("renders items ", () => {
-    const result = render(
-      <RecyclerView
-        data={[
-          "One",
-          "Two",
-          "Three",
-          "Four",
-          "Five",
-          "Six",
-          "Seven",
-          "Eight",
-          "Nine",
-          "Ten",
-          "Eleven",
-          "Twelve",
-          "Thirteen",
-          "Fourteen",
-          "Fifteen",
-        ]}
-        renderItem={({ item }) => <Text>{item}</Text>}
-      />
-    );
+  describe("Horizontal Layout", () => {
+    it("renders items with horizontal", () => {
+      const result = renderRecyclerView({ horizontal: true });
 
-    expect(result).toContainReactComponent(Text, { children: "One" });
-    expect(result).not.toContainReactComponent(Text, { children: "Eleven" });
+      expect(result).toContainReactComponent(Text, { children: 0 });
+      expect(result).not.toContainReactComponent(Text, { children: 5 });
+    });
   });
 });

src/recyclerview/RecyclerViewManager.ts

@@ -117,6 +117,9 @@ export class RecyclerViewManager<T> {
     } else {
       this.initialDrawBatchSize = (props.numColumns ?? 1) * 2;
     }
+    this.initialDrawBatchSize =
+      this.propsRef.overrideProps?.initialDrawBatchSize ??
+      this.initialDrawBatchSize;
   }
 
   /**

src/recyclerview/layout-managers/LayoutManager.ts

@@ -114,8 +114,8 @@ export abstract class RVLayoutManager {
   /**
    * Gets indices of items currently visible in the viewport.
    * Uses binary search for efficient lookup.
-   * @param unboundDimensionStart Start position of viewport
-   * @param unboundDimensionEnd End position of viewport
+   * @param unboundDimensionStart Start position of viewport (start X or start Y)
+   * @param unboundDimensionEnd End position of viewport (end X or end Y)
    * @returns ConsecutiveNumbers containing visible indices
    */
   getVisibleLayouts(