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/widgets/__tests__/generate-widgets.spec.ts

@@ -0,0 +1,83 @@
+import { vi } from "vitest"
+
+import fs from "fs/promises"
+import * as utils from "../../utils"
+import { generateWidgets } from "../generate-widgets"
+
+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 { defineWidgetConfig } from "@medusajs/admin-sdk"
+
+    const Widget = () => {
+        return <div>Widget 1</div>
+    }
+
+    export const config = defineWidgetConfig({
+        zone: "product.details.after",
+    })
+
+    export default Widget
+`,
+]
+
+const expectedWidgets = `
+    widgets: [
+        {
+            Component: WidgetComponent0,
+            zone: ["product.details.after"]
+        }
+    ]
+`
+
+describe("generateWidgets", () => {
+  it("should generate widgets", async () => {
+    const mockFiles = ["Users/user/medusa/src/admin/widgets/widget.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 generateWidgets(
+      new Set(["Users/user/medusa/src/admin"])
+    )
+
+    expect(result.imports).toEqual([
+      `import WidgetComponent0, { config as WidgetConfig0 } from "Users/user/medusa/src/admin/widgets/widget.tsx"`,
+    ])
+    expect(utils.normalizeString(result.code)).toEqual(
+      utils.normalizeString(expectedWidgets)
+    )
+  })
+  it("should handle windows paths", async () => {
+    const mockFiles = ["C:\\medusa\\src\\admin\\widgets\\widget.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 generateWidgets(new Set(["C:\\medusa\\src\\admin"]))
+
+    expect(result.imports).toEqual([
+      `import WidgetComponent0, { config as WidgetConfig0 } from "C:/medusa/src/admin/widgets/widget.tsx"`,
+    ])
+    expect(utils.normalizeString(result.code)).toEqual(
+      utils.normalizeString(expectedWidgets)
+    )
+  })
+})

packages/admin/admin-vite-plugin/src/widgets/generate-widgets.ts

@@ -16,6 +16,7 @@ import {
   getConfigObjectProperties,
   getParserOptions,
   hasDefaultExport,
+  normalizePath,
 } from "../utils"
 import { getWidgetFilesFromSources } from "./helpers"
 
@@ -135,9 +136,10 @@ function generateWidgetConfigName(index: number): string {
 }
 
 function generateImport(file: string, index: number): string {
+  const path = normalizePath(file)
   return `import ${generateWidgetComponentName(
     index
-  )}, { config as ${generateWidgetConfigName(index)} } from "${file}"`
+  )}, { config as ${generateWidgetConfigName(index)} } from "${path}"`
 }
 
 function generateWidget(zone: InjectionZone[], index: number): WidgetConfig {