feat: Add validation for import aliases (#1255)

* feat: do not allow invalid import aliases

* chore: add changeset

* fix: use validate instead of custom logic

* fix: update changeset to better match changes

* refactor: change naming from path alias to import alias

---------

Co-authored-by: Christopher Ehrlich <[email protected]>

Author: justasam

Diff for: .changeset/great-buckets-relate.md

@@ -0,0 +1,5 @@
+---
+"create-t3-app": minor
+---
+
+Add import alias validation

Diff for: cli/src/cli/index.ts

@@ -8,6 +8,7 @@ import { getVersion } from "~/utils/getT3Version.js";
 import { getUserPkgManager } from "~/utils/getUserPkgManager.js";
 import { logger } from "~/utils/logger.js";
 import { validateAppName } from "~/utils/validateAppName.js";
+import { validateImportAlias } from "~/utils/validateImportAlias.js";
 
 interface CliFlags {
   noGit: boolean;
@@ -322,6 +323,7 @@ const promptImportAlias = async (): Promise<string> => {
     type: "input",
     message: "What import alias would you like configured?",
     default: defaultOptions.flags.importAlias,
+    validate: validateImportAlias,
     transformer: (input: string) => {
       return input.trim();
     },

Diff for: cli/src/utils/validateImportAlias.ts

@@ -0,0 +1,7 @@
+export const validateImportAlias = (input: string) => {
+  if (input.startsWith(".") || input.startsWith("/")) {
+    return "Import alias can't start with '.' or '/'";
+  } else {
+    return true;
+  }
+};