fix: improve error message upon unexpected module ID (#1985)

vike/utils/virtual-files.ts

@@ -2,7 +2,8 @@ export { isVirtualFileId }
 export { getVirtualFileId }
 export { resolveVirtualFileId }
 
-import { assert } from './assert.js'
+import pc from '@brillout/picocolors'
+import { assert, assertUsage } from './assert.js'
 
 const idBase = 'virtual:vike:'
 // https://vitejs.dev/guide/api-plugin.html#virtual-modules-convention
@@ -11,7 +12,13 @@ const tag = '\0'
 function isVirtualFileId(id: string): boolean {
   if (id.startsWith(idBase)) return true
   if (id.startsWith(tag + idBase)) return true
-  assert(!id.includes(idBase))
+  // https://github.com/vikejs/vike/issues/1985
+  assertUsage(
+    !id.includes(idBase),
+    `Encountered a module ID ${pc.cyan(
+      id
+    )} that is unexpected. Are you using a tool that modifies the ID of modules? For example, the baseUrl setting in tsconfig.json cannot be used.`
+  )
   return false
 }
 function getVirtualFileId(id: string): string {