Refactor entity count formatting to support translations

packages/graph-explorer/src/core/StateProvider/graphSession/useRestoreGraphSession.ts

@@ -3,7 +3,8 @@ import { toast } from "sonner";
 
 import { fetchEntityDetails, notifyOnIncompleteRestoration } from "@/connector";
 import { useAddToGraph } from "@/hooks";
-import { formatEntityCounts, logger } from "@/utils";
+import { useEntityCountFormatterCallback } from "@/hooks/useEntityCountFormatter";
+import { logger } from "@/utils";
 import { createDisplayError } from "@/utils/createDisplayError";
 
 import type { GraphSessionStorageModel } from "./storage";
@@ -14,6 +15,7 @@ import type { GraphSessionStorageModel } from "./storage";
 export function useRestoreGraphSession() {
   const queryClient = useQueryClient();
   const addToGraph = useAddToGraph();
+  const formatEntityCounts = useEntityCountFormatterCallback();
 
   const mutation = useMutation({
     mutationFn: async (graph: GraphSessionStorageModel) => {

packages/graph-explorer/src/hooks/useEntityCountFormatter.test.ts

@@ -0,0 +1,89 @@
+import { vi } from "vitest";
+
+import { renderHookWithJotai } from "@/utils/testing";
+
+import {
+  useEntityCountFormatterCallback,
+  useFormattedEntityCounts,
+} from "./useEntityCountFormatter";
+
+// Mock useTranslations
+vi.mock("./useTranslations", () => ({
+  default: () => (key: string) => {
+    const translations: Record<string, string> = {
+      node: "node",
+      nodes: "nodes",
+      edge: "edge",
+      edges: "edges",
+    };
+    return translations[key] || key;
+  },
+}));
+
+describe("useFormattedEntityCounts", () => {
+  it("should format single node and single edge", () => {
+    const { result } = renderHookWithJotai(() =>
+      useFormattedEntityCounts(1, 1),
+    );
+    expect(result.current).toBe("1 node and 1 edge");
+  });
+
+  it("should format multiple nodes and multiple edges", () => {
+    const { result } = renderHookWithJotai(() =>
+      useFormattedEntityCounts(5, 3),
+    );
+    expect(result.current).toBe("5 nodes and 3 edges");
+  });
+
+  it("should format only nodes when edge count is zero", () => {
+    const { result } = renderHookWithJotai(() =>
+      useFormattedEntityCounts(2, 0),
+    );
+    expect(result.current).toBe("2 nodes");
+  });
+
+  it("should format only edges when node count is zero", () => {
+    const { result } = renderHookWithJotai(() =>
+      useFormattedEntityCounts(0, 4),
+    );
+    expect(result.current).toBe("4 edges");
+  });
+
+  it("should return empty string when both counts are zero", () => {
+    const { result } = renderHookWithJotai(() =>
+      useFormattedEntityCounts(0, 0),
+    );
+    expect(result.current).toBe("");
+  });
+
+  it("should format large numbers with locale formatting", () => {
+    const { result } = renderHookWithJotai(() =>
+      useFormattedEntityCounts(1000, 2500),
+    );
+    expect(result.current).toBe("1,000 nodes and 2,500 edges");
+  });
+});
+
+describe("useEntityCountFormatterCallback", () => {
+  it("should return a function that formats counts", () => {
+    const { result } = renderHookWithJotai(() =>
+      useEntityCountFormatterCallback(),
+    );
+
+    expect(typeof result.current).toBe("function");
+    expect(result.current(1, 1)).toBe("1 node and 1 edge");
+  });
+
+  it("should handle different count combinations", () => {
+    const { result } = renderHookWithJotai(() =>
+      useEntityCountFormatterCallback(),
+    );
+
+    const format = result.current;
+
+    expect(format(0, 0)).toBe("");
+    expect(format(1, 0)).toBe("1 node");
+    expect(format(0, 1)).toBe("1 edge");
+    expect(format(10, 5)).toBe("10 nodes and 5 edges");
+  });
+});

packages/graph-explorer/src/hooks/useEntityCountFormatter.ts

@@ -0,0 +1,29 @@
+import useTranslations from "./useTranslations";
+
+export function useFormattedEntityCounts(
+  vertexCount: number,
+  edgeCount: number,
+) {
+  const format = useEntityCountFormatterCallback();
+  return format(vertexCount, edgeCount);
+}
+
+export function useEntityCountFormatterCallback() {
+  const t = useTranslations();
+
+  const format = (vertexCount: number, edgeCount: number) => {
+    const nodeMessage =
+      vertexCount === 0
+        ? null
+        : `${vertexCount.toLocaleString()} ${vertexCount === 1 ? t("node") : t("nodes")}`.toLocaleLowerCase();
+    const edgeMessage =
+      edgeCount === 0
+        ? null
+        : `${edgeCount.toLocaleString()} ${edgeCount === 1 ? t("edge") : t("edges")}`.toLocaleLowerCase();
+
+    return [nodeMessage, edgeMessage]
+      .filter(message => message != null)
+      .join(" and ");
+  };
+  return format;
+}

packages/graph-explorer/src/modules/GraphViewer/GraphViewerEmptyState.tsx

@@ -10,7 +10,8 @@ import {
   useAvailablePreviousSession,
   useRestoreGraphSession,
 } from "@/core";
-import { cn, formatEntityCounts } from "@/utils";
+import { useFormattedEntityCounts } from "@/hooks/useEntityCountFormatter";
+import { cn } from "@/utils";
 
 export function GraphViewerEmptyState(props: ComponentPropsWithRef<"div">) {
   const availablePrevSession = useAvailablePreviousSession();
@@ -35,7 +36,7 @@ function RestorePreviousSessionEmptyState({
 } & ComponentPropsWithRef<"div">) {
   const restore = useRestoreGraphSession();
 
-  const entityCounts = formatEntityCounts(
+  const entityCounts = useFormattedEntityCounts(
     prevSession.vertices.size,
     prevSession.edges.size,
   );

packages/graph-explorer/src/modules/GraphViewer/ImportGraphButton.tsx

@@ -8,8 +8,9 @@ import { FileButton, PanelHeaderActionButton, Spinner } from "@/components";
 import { fetchEntityDetails, notifyOnIncompleteRestoration } from "@/connector";
 import { configurationAtom, type ConnectionWithId, useExplorer } from "@/core";
 import { useAddToGraph } from "@/hooks";
+import { useEntityCountFormatterCallback } from "@/hooks/useEntityCountFormatter";
 import { getTranslation } from "@/hooks/useTranslations";
-import { formatEntityCounts, logger } from "@/utils";
+import { logger } from "@/utils";
 import { fromFileToJson } from "@/utils/fileData";
 
 import {
@@ -40,6 +41,7 @@ function useImportGraphMutation() {
   const queryClient = useQueryClient();
   const explorer = useExplorer();
   const addToGraph = useAddToGraph();
+  const formatEntityCounts = useEntityCountFormatterCallback();
   const allConfigs = useAtomValue(configurationAtom);
   const allConnections = allConfigs
     .values()