fix: respect import map files containing only scopes (#495)

node/import_map.test.ts

@@ -7,6 +7,7 @@ import tmp from 'tmp-promise'
 import { describe, test, expect } from 'vitest'
 
 import { ImportMap } from './import_map.js'
+import { getLogger } from './logger.js'
 
 test('Handles import maps with full URLs without specifying a base URL', () => {
   const basePath = join(cwd(), 'my-cool-site', 'import-map.json')
@@ -176,6 +177,32 @@ test('Writes import map file to disk', async () => {
   expect(imports['alias:pets']).toBe(pathToFileURL(expectedPath).toString())
 })
 
+test('Respects import map when it has only scoped key', async () => {
+  const file = await tmp.file()
+  const importMap = {
+    scopes: {
+      './foo': {
+        'alias:pets': './heart/pets/file.ts',
+      },
+    },
+  }
+  await fs.writeFile(file.path, JSON.stringify(importMap))
+  const map = new ImportMap()
+  await map.addFile(file.path, getLogger())
+
+  expect(map.getContents()).toEqual({
+    imports: {
+      'netlify:edge': 'https://edge.netlify.com/v1/index.ts?v=legacy',
+      '@netlify/edge-functions': 'https://edge.netlify.com/v1/index.ts',
+    },
+    scopes: {
+      [pathToFileURL(join(file.path, '../foo')).href]: {
+        'alias:pets': pathToFileURL(join(file.path, '../heart/pets/file.ts')).href,
+      },
+    },
+  })
+})
+
 test('Clones an import map', () => {
   const basePath = join(cwd(), 'my-cool-site', 'import-map.json')
   const inputFile1 = {

node/import_map.ts

@@ -17,7 +17,7 @@ type Imports = Record<string, string>
 
 export interface ImportMapFile {
   baseURL: URL
-  imports: Imports
+  imports?: Imports
   scopes?: Record<string, Imports>
 }
 
@@ -47,10 +47,6 @@ export class ImportMap {
   async addFile(path: string, logger: Logger) {
     const source = await ImportMap.readFile(path, logger)
 
-    if (Object.keys(source.imports).length === 0) {
-      return
-    }
-
     return this.add(source)
   }