refactor(insights): share workbook export and ai defaults

apps/web/src/lib/workbook-export.test.ts

@@ -0,0 +1,53 @@
+import { describe, expect, it } from "vitest";
+import {
+  createWorkbookArrayBuffer,
+  createWorkbookArrayBufferFromSheets,
+} from "./workbook-export.js";
+
+describe("workbook export helpers", () => {
+  it("writes a single-sheet workbook with primitive values", async () => {
+    const buffer = await createWorkbookArrayBuffer("Skills", [
+      ["Skill", "Count", "Active"],
+      ["TypeScript", 4, true],
+      ["Planning", 2, false],
+    ]);
+
+    const ExcelJS = await import("exceljs");
+    const workbook = new ExcelJS.Workbook();
+    await workbook.xlsx.load(Buffer.from(buffer));
+
+    const worksheet = workbook.getWorksheet("Skills");
+    expect(worksheet).toBeDefined();
+    expect(worksheet?.getRow(1).values).toEqual([, "Skill", "Count", "Active"]);
+    expect(worksheet?.getRow(2).values).toEqual([, "TypeScript", 4, true]);
+    expect(worksheet?.getRow(3).values).toEqual([, "Planning", 2, false]);
+  });
+
+  it("writes all provided sheets into the workbook", async () => {
+    const buffer = await createWorkbookArrayBufferFromSheets([
+      {
+        name: "Overview",
+        rows: [["Metric", "Value"], ["Resources", 12]],
+      },
+      {
+        name: "People Finder",
+        rows: [["Name", "Skills"], ["Peter Parker", "Staffing, Forecasting"]],
+      },
+    ]);
+
+    const ExcelJS = await import("exceljs");
+    const workbook = new ExcelJS.Workbook();
+    await workbook.xlsx.load(Buffer.from(buffer));
+
+    expect(workbook.worksheets.map((sheet) => sheet.name)).toEqual([
+      "Overview",
+      "People Finder",
+    ]);
+    expect(workbook.getWorksheet("Overview")?.getRow(2).values).toEqual([, "Resources", 12]);
+    expect(workbook.getWorksheet("People Finder")?.getRow(2).values).toEqual([
+      ,
+      "Peter Parker",
+      "Staffing, Forecasting",
+    ]);
+  });
+});