fix(admin-vite-plugin): Normalize file paths and add tests (#9595)

**What**
- #9338 had a regression which caused the import path in some virtual modules to be invalid on Windows.
- This PR fixes the issue so we now again create the correct import paths, and adds tests to prevent this from slipping in again.

packages/admin/admin-vite-plugin/src/routes/__tests__/generate-menu-items.spec.ts

@@ -0,0 +1,113 @@
+import { describe, expect, it, vi } from "vitest"
+
+import fs from "fs/promises"
+import * as utils from "../../utils"
+import { generateMenuItems } from "../generate-menu-items"
+
+vi.mock("../../utils", async () => {
+  const actual = await vi.importActual("../../utils")
+  return {
+    ...actual,
+    crawl: vi.fn(),
+  }
+})
+
+vi.mock("fs/promises", () => ({
+  default: {
+    readFile: vi.fn(),
+  },
+}))
+
+const mockFileContents = [
+  `
+    import { defineRouteConfig } from "@medusajs/admin-sdk"
+
+    const Page = () => {
+        return <div>Page 1</div>
+    }
+
+    export const config = defineRouteConfig({
+        label: "Page 1",
+        icon: "icon1",
+    })
+
+    export default Page
+    `,
+  `
+    import { defineRouteConfig } from "@medusajs/admin-sdk"
+
+    const Page = () => {
+        return <div>Page 2</div>
+    }
+
+    export const config = defineRouteConfig({
+        label: "Page 2",
+    })
+
+    export default Page
+  `,
+]
+
+const expectedMenuItems = `
+        menuItems: [
+          {
+            label: RouteConfig0.label,
+            icon: RouteConfig0.icon,
+            path: "/one",
+          },
+          {
+            label: RouteConfig1.label,
+            icon: undefined,
+            path: "/two",
+          }
+        ]
+      `
+
+describe("generateMenuItems", () => {
+  it("should generate menu items", async () => {
+    const mockFiles = [
+      "Users/user/medusa/src/admin/routes/one/page.tsx",
+      "Users/user/medusa/src/admin/routes/two/page.tsx",
+    ]
+    vi.mocked(utils.crawl).mockResolvedValue(mockFiles)
+
+    vi.mocked(fs.readFile).mockImplementation(async (file) =>
+      Promise.resolve(mockFileContents[mockFiles.indexOf(file as string)])
+    )
+
+    const result = await generateMenuItems(
+      new Set(["Users/user/medusa/src/admin"])
+    )
+
+    expect(result.imports).toEqual([
+      `import { config as RouteConfig0 } from "Users/user/medusa/src/admin/routes/one/page.tsx"`,
+      `import { config as RouteConfig1 } from "Users/user/medusa/src/admin/routes/two/page.tsx"`,
+    ])
+    expect(utils.normalizeString(result.code)).toEqual(
+      utils.normalizeString(expectedMenuItems)
+    )
+  })
+
+  it("should handle windows paths", async () => {
+    // Setup mocks
+    const mockFiles = [
+      "C:\\medusa\\src\\admin\\routes\\one\\page.tsx",
+      "C:\\medusa\\src\\admin\\routes\\two\\page.tsx",
+    ]
+    vi.mocked(utils.crawl).mockResolvedValue(mockFiles)
+
+    vi.mocked(fs.readFile).mockImplementation(async (file) =>
+      Promise.resolve(mockFileContents[mockFiles.indexOf(file as string)])
+    )
+
+    const result = await generateMenuItems(new Set(["C:\\medusa\\src\\admin"]))
+
+    expect(result.imports).toEqual([
+      `import { config as RouteConfig0 } from "C:/medusa/src/admin/routes/one/page.tsx"`,
+      `import { config as RouteConfig1 } from "C:/medusa/src/admin/routes/two/page.tsx"`,
+    ])
+    expect(utils.normalizeString(result.code)).toEqual(
+      utils.normalizeString(expectedMenuItems)
+    )
+  })
+})

packages/admin/admin-vite-plugin/src/routes/__tests__/generate-routes.spec.ts

@@ -0,0 +1,144 @@
+import { describe, expect, it, vi } from "vitest"
+
+import { Stats } from "fs"
+import fs from "fs/promises"
+import * as utils from "../../utils"
+import { generateRoutes } from "../generate-routes"
+
+// Mock the dependencies
+vi.mock("../../utils", async () => {
+  const actual = await vi.importActual("../../utils")
+  return {
+    ...actual,
+    crawl: vi.fn(),
+  }
+})
+
+vi.mock("fs/promises", () => ({
+  default: {
+    readFile: vi.fn(),
+    stat: vi.fn(),
+  },
+}))
+
+const mockFileContents = [
+  `
+    import { defineRouteConfig } from "@medusajs/admin-sdk"
+
+    const Page = () => {
+        return <div>Page 1</div>
+    }
+
+    export const config = defineRouteConfig({
+        label: "Page 1",
+        icon: "icon1",
+    })
+
+    export default Page
+    `,
+  `
+    import { defineRouteConfig } from "@medusajs/admin-sdk"
+
+    const Page = () => {
+        return <div>Page 2</div>
+    }
+
+    export const config = defineRouteConfig({
+        label: "Page 2",
+    })
+
+    export default Page
+  `,
+]
+
+const expectedRoutesWithoutLoaders = `
+    routes: [
+        {
+            Component: RouteComponent0,
+            loader: undefined,
+            path: "/one",
+        },
+        {
+            Component: RouteComponent1,
+            loader: undefined,
+            path: "/two",
+        }
+    ]
+`
+
+const expectedRoutesWithLoaders = `
+    routes: [
+        {
+            Component: RouteComponent0,
+            loader: RouteLoader0,
+            path: "/one",
+        },
+        {
+            Component: RouteComponent1,
+            loader: RouteLoader1,
+            path: "/two",
+        }
+    ]
+`
+
+describe("generateRoutes", () => {
+  it("should generate routes", async () => {
+    const mockFiles = [
+      "Users/user/medusa/src/admin/routes/one/page.tsx",
+      "Users/user/medusa/src/admin/routes/two/page.tsx",
+    ]
+    vi.mocked(utils.crawl).mockResolvedValue(mockFiles)
+
+    vi.mocked(fs.readFile).mockImplementation(async (file) =>
+      Promise.resolve(mockFileContents[mockFiles.indexOf(file as string)])
+    )
+
+    vi.mocked(fs.stat).mockRejectedValue(new Error("File not found"))
+
+    const result = await generateRoutes(
+      new Set(["Users/user/medusa/src/admin"])
+    )
+    expect(utils.normalizeString(result.code)).toEqual(
+      utils.normalizeString(expectedRoutesWithoutLoaders)
+    )
+  })
+  it("should generate routes with loaders", async () => {
+    const mockFiles = [
+      "Users/user/medusa/src/admin/routes/one/page.tsx",
+      "Users/user/medusa/src/admin/routes/two/page.tsx",
+    ]
+    vi.mocked(utils.crawl).mockResolvedValue(mockFiles)
+
+    vi.mocked(fs.readFile).mockImplementation(async (file) =>
+      Promise.resolve(mockFileContents[mockFiles.indexOf(file as string)])
+    )
+
+    vi.mocked(fs.stat).mockResolvedValue({} as Stats) // We just want to mock that the check passes
+
+    const result = await generateRoutes(
+      new Set(["Users/user/medusa/src/admin"])
+    )
+    expect(utils.normalizeString(result.code)).toEqual(
+      utils.normalizeString(expectedRoutesWithLoaders)
+    )
+  })
+  it("should handle windows paths", async () => {
+    const mockFiles = [
+      "C:\\medusa\\src\\admin\\routes\\one\\page.tsx",
+      "C:\\medusa\\src\\admin\\routes\\two\\page.tsx",
+    ]
+    vi.mocked(utils.crawl).mockResolvedValue(mockFiles)
+
+    vi.mocked(fs.readFile).mockImplementation(async (file) =>
+      Promise.resolve(mockFileContents[mockFiles.indexOf(file as string)])
+    )
+
+    vi.mocked(fs.stat).mockRejectedValue(new Error("File not found"))
+
+    const result = await generateRoutes(new Set(["C:\\medusa\\src\\admin"]))
+
+    expect(utils.normalizeString(result.code)).toEqual(
+      utils.normalizeString(expectedRoutesWithoutLoaders)
+    )
+  })
+})

packages/admin/admin-vite-plugin/src/routes/generate-menu-items.ts

@@ -2,7 +2,12 @@ import fs from "fs/promises"
 import { outdent } from "outdent"
 import { isIdentifier, isObjectProperty, parse, traverse } from "../babel"
 import { logger } from "../logger"
-import { crawl, getConfigObjectProperties, getParserOptions } from "../utils"
+import {
+  crawl,
+  getConfigObjectProperties,
+  getParserOptions,
+  normalizePath,
+} from "../utils"
 import { getRoute } from "./helpers"
 
 type MenuItem = {
@@ -90,7 +95,8 @@ async function parseFile(
 }
 
 function generateImport(file: string, index: number): string {
-  return `import { config as ${generateRouteConfigName(index)} } from "${file}"`
+  const path = normalizePath(file)
+  return `import { config as ${generateRouteConfigName(index)} } from "${path}"`
 }
 
 function generateMenuItem(