diff --git a/js/package.json b/js/package.json
index c6d04403a..81765325b 100644
--- a/js/package.json
+++ b/js/package.json
@@ -19,7 +19,8 @@
     "test": "vitest run",
     "test:watch": "vitest",
     "test:cov": "vitest run --coverage",
-    "type:check": "tsc --noEmit",
+    "type:check": "pnpm type:check:root && pnpm --filter @datarecce/ui type:check && pnpm --filter @datarecce/storybook type:check",
+    "type:check:root": "tsc --noEmit",
     "clean": "rimraf ../recce/data",
     "prepare": "cd .. && husky js/.husky"
   },
diff --git a/js/packages/storybook/package.json b/js/packages/storybook/package.json
index 8a058a984..91335b95b 100644
--- a/js/packages/storybook/package.json
+++ b/js/packages/storybook/package.json
@@ -8,6 +8,7 @@
     "build": "storybook build -o dist",
     "test": "vitest run",
     "test:watch": "vitest",
+    "type:check": "tsc --noEmit",
     "test:visual": "playwright test",
     "test:visual:update": "playwright test --update-snapshots"
   },
diff --git a/js/packages/storybook/tsconfig.json b/js/packages/storybook/tsconfig.json
index 1f0f53c12..88ac10412 100644
--- a/js/packages/storybook/tsconfig.json
+++ b/js/packages/storybook/tsconfig.json
@@ -8,5 +8,12 @@
       "@datarecce/ui/*": ["../ui/src/*"]
     }
   },
-  "include": ["stories/**/*", ".storybook/**/*", "vitest.config.ts"]
+  "include": [
+    "stories/**/*",
+    ".storybook/**/*",
+    "vitest.config.ts",
+    "../../mui-augmentations.d.ts",
+    "../ui/src/components/ui/mui-utils.ts",
+    "../ui/src/css.d.ts"
+  ]
 }
diff --git a/js/packages/ui/src/components/lineage/changeCategory.ts b/js/packages/ui/src/components/lineage/changeCategory.ts
index 8f9f8e26d..16666178c 100644
--- a/js/packages/ui/src/components/lineage/changeCategory.ts
+++ b/js/packages/ui/src/components/lineage/changeCategory.ts
@@ -1,3 +1,4 @@
+import { hasOwn } from "../../utils/hasOwn";
 import type { ChangeCategory } from "./nodes/LineageNode";
 
 export const CHANGE_CATEGORY_LABELS: Record<ChangeCategory, string> = {
@@ -30,7 +31,7 @@ export const CHANGE_CATEGORY_DETAILS: ReadonlyArray<{
 ];
 
 function isChangeCategory(value: string | undefined): value is ChangeCategory {
-  return value !== undefined && Object.hasOwn(CHANGE_CATEGORY_LABELS, value);
+  return value !== undefined && hasOwn(CHANGE_CATEGORY_LABELS, value);
 }
 
 export function getChangeCategoryLabel(
diff --git a/js/packages/ui/src/components/lineage/hooks/useTrackLineageRender.ts b/js/packages/ui/src/components/lineage/hooks/useTrackLineageRender.ts
index 8c0004cc8..110b3ad0e 100644
--- a/js/packages/ui/src/components/lineage/hooks/useTrackLineageRender.ts
+++ b/js/packages/ui/src/components/lineage/hooks/useTrackLineageRender.ts
@@ -22,16 +22,14 @@ export const useTrackLineageRender = () => {
       rightSidebarOpen: boolean,
     ) => {
       const lineageGraphNodesOnly = nodes.filter(isLineageGraphNode);
-      const grouped = Object.groupBy(
-        lineageGraphNodesOnly,
-        (node) => node.data.changeStatus ?? "unchanged",
-      );
       // Prefix status counts with "nodes_"
-      const statusCounts = Object.fromEntries(
-        Object.entries(grouped).map(([status, nodes]) => [
-          `nodes_${status}`,
-          nodes?.length ?? 0,
-        ]),
+      const statusCounts = lineageGraphNodesOnly.reduce<Record<string, number>>(
+        (counts, node) => {
+          const key = `nodes_${node.data.changeStatus ?? "unchanged"}`;
+          counts[key] = (counts[key] ?? 0) + 1;
+          return counts;
+        },
+        {},
       );
       const trackingData = {
         node_count: lineageGraphNodesOnly.length,
diff --git a/js/packages/ui/src/components/result/createResultView.test.tsx b/js/packages/ui/src/components/result/createResultView.test.tsx
index cc0ff04fe..a7e2be607 100644
--- a/js/packages/ui/src/components/result/createResultView.test.tsx
+++ b/js/packages/ui/src/components/result/createResultView.test.tsx
@@ -32,7 +32,7 @@ vi.mock("ag-grid-community", () => ({
 
 // Mock ScreenshotDataGrid component
 vi.mock("../data/ScreenshotDataGrid", async () => {
-  const utils = await vi.importActual("@/testing-utils/resultViewTestUtils");
+  const utils = await vi.importActual("./createResultView.testUtils");
   return {
     ScreenshotDataGrid: (utils as { screenshotDataGridMock: unknown })
       .screenshotDataGridMock,
@@ -44,7 +44,7 @@ vi.mock("../data/ScreenshotDataGrid", async () => {
 
 // Mock ScreenshotBox component
 vi.mock("../ui/ScreenshotBox", async () => {
-  const utils = await vi.importActual("@/testing-utils/resultViewTestUtils");
+  const utils = await vi.importActual("./createResultView.testUtils");
   return {
     ScreenshotBox: (utils as { screenshotBoxMock: unknown }).screenshotBoxMock,
   };
@@ -62,10 +62,9 @@ vi.mock("../../hooks", () => ({
 
 import { screen } from "@testing-library/react";
 import { createRef, type ReactNode } from "react";
-import type { MockDataGridHandle } from "@/testing-utils/resultViewTestUtils";
-import { renderWithProviders } from "@/testing-utils/resultViewTestUtils";
 import type { DataGridHandle } from "../data/ScreenshotDataGrid";
 import { createResultView } from "./createResultView";
+import { renderWithProviders } from "./createResultView.testUtils";
 import type { ResultViewData } from "./types";
 
 // ============================================================================
diff --git a/js/packages/ui/src/components/result/createResultView.testUtils.tsx b/js/packages/ui/src/components/result/createResultView.testUtils.tsx
new file mode 100644
index 000000000..bd53860d8
--- /dev/null
+++ b/js/packages/ui/src/components/result/createResultView.testUtils.tsx
@@ -0,0 +1,71 @@
+import { ThemeProvider } from "@mui/material/styles";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { type RenderOptions, render } from "@testing-library/react";
+import React, { type ReactNode } from "react";
+import { theme } from "../../theme";
+
+export const screenshotBoxMock = React.forwardRef<
+  HTMLDivElement,
+  { children?: ReactNode }
+>(function MockScreenshotBox({ children }, ref) {
+  return (
+    <div ref={ref} data-testid="screenshot-box-mock">
+      {children}
+    </div>
+  );
+});
+
+export const screenshotDataGridMock = React.forwardRef<
+  {
+    api: null;
+    element: null;
+  },
+  {
+    columns?: unknown[];
+    rows?: unknown[];
+    children?: ReactNode;
+  }
+>(function MockScreenshotDataGrid({ columns, rows, children }, ref) {
+  React.useImperativeHandle(ref, () => ({
+    api: null,
+    element: null,
+  }));
+
+  const columnCount = columns?.length ?? 0;
+  const rowCount = rows?.length ?? 0;
+
+  return (
+    <div
+      data-testid="screenshot-data-grid-mock"
+      data-columns={columnCount}
+      data-rows={rowCount}
+    >
+      {children ?? `Mock Grid: ${rowCount} rows, ${columnCount} columns`}
+    </div>
+  );
+});
+
+function TestProviders({ children }: { children: ReactNode }) {
+  const queryClient = new QueryClient({
+    defaultOptions: {
+      queries: {
+        retry: false,
+        refetchOnWindowFocus: false,
+        refetchOnMount: false,
+      },
+    },
+  });
+
+  return (
+    <QueryClientProvider client={queryClient}>
+      <ThemeProvider theme={theme}>{children}</ThemeProvider>
+    </QueryClientProvider>
+  );
+}
+
+export function renderWithProviders(
+  ui: React.ReactElement,
+  options?: Omit<RenderOptions, "wrapper">,
+): ReturnType<typeof render> {
+  return render(ui, { wrapper: TestProviders, ...options });
+}
diff --git a/js/packages/ui/src/components/ui/dataGrid/dataGridFactory.tsx b/js/packages/ui/src/components/ui/dataGrid/dataGridFactory.tsx
index d7d2b912f..3b9f3f785 100644
--- a/js/packages/ui/src/components/ui/dataGrid/dataGridFactory.tsx
+++ b/js/packages/ui/src/components/ui/dataGrid/dataGridFactory.tsx
@@ -56,6 +56,7 @@ import {
   toRowCountDiffDataGrid,
   toValueDiffGridConfigured as toValueDiffGrid,
 } from "../../../utils/dataGrid";
+import { hasOwn } from "../../../utils/hasOwn";
 import { getCaseInsensitive } from "../../../utils/transforms";
 import { buildColumnTooltip, DataTypeIcon } from "../DataTypeIcon";
 import { toValueDataGrid } from "./generators/toValueDataGrid";
@@ -330,7 +331,7 @@ export function injectProfileColumnNameRenderer(
   result: DataGridResult,
 ): DataGridResult {
   const isInlineDiff =
-    result.rows.length > 0 && Object.hasOwn(result.rows[0], "base__data_type");
+    result.rows.length > 0 && hasOwn(result.rows[0], "base__data_type");
 
   const columns = result.columns
     .filter((col) => {
diff --git a/js/packages/ui/src/components/ui/dataGrid/inlineRenderCell.tsx b/js/packages/ui/src/components/ui/dataGrid/inlineRenderCell.tsx
index 43a750689..8e26a0720 100644
--- a/js/packages/ui/src/components/ui/dataGrid/inlineRenderCell.tsx
+++ b/js/packages/ui/src/components/ui/dataGrid/inlineRenderCell.tsx
@@ -22,6 +22,7 @@ import {
   isCellChanged,
   toRenderedValue,
 } from "../../../utils/dataGrid/gridUtils";
+import { hasOwn } from "../../../utils/hasOwn";
 import { DiffText, type DiffTextProps } from "../DiffText";
 import { DiffTextWithToast } from "../DiffTextWithToast";
 
@@ -100,12 +101,12 @@ export function createInlineRenderCell(config: InlineRenderCellConfig = {}) {
     const currentKey = `current__${columnKey}`.toLowerCase();
 
     // Handle case where neither base nor current values exist
-    if (!Object.hasOwn(row, baseKey) && !Object.hasOwn(row, currentKey)) {
+    if (!hasOwn(row, baseKey) && !hasOwn(row, currentKey)) {
       return "-";
     }
 
-    const hasBase = Object.hasOwn(row, baseKey);
-    const hasCurrent = Object.hasOwn(row, currentKey);
+    const hasBase = hasOwn(row, baseKey);
+    const hasCurrent = hasOwn(row, currentKey);
 
     const [baseValue, baseGrayOut] = toRenderedValue(
       row,
diff --git a/js/packages/ui/src/css.d.ts b/js/packages/ui/src/css.d.ts
new file mode 100644
index 000000000..cbe652dbe
--- /dev/null
+++ b/js/packages/ui/src/css.d.ts
@@ -0,0 +1 @@
+declare module "*.css";
diff --git a/js/packages/ui/src/utils/hasOwn.ts b/js/packages/ui/src/utils/hasOwn.ts
new file mode 100644
index 000000000..a8df73703
--- /dev/null
+++ b/js/packages/ui/src/utils/hasOwn.ts
@@ -0,0 +1,4 @@
+export function hasOwn(object: object, property: PropertyKey): boolean {
+  // biome-ignore lint/suspicious/noPrototypeBuiltins: Storybook's ES2020 target does not provide Object.hasOwn.
+  return Object.prototype.hasOwnProperty.call(object, property);
+}