No Error Thrown When a Non-Image File Is Used as a Costume

[aspizu]

Summary

Specifying a non-image file in the costumes directive produces no error. Only image files should be accepted.

Steps to Reproduce

costumes "project.json";

Expected Behavior

A compile error should be raised indicating that the file is not a valid image.

error: invalid costume: "project.json" is not an image file
 --> playground/main.gs:1:10
  |
1 |     costumes "project.json";
  |              ^^^^^^^^^^^^^^^
  |

Actual Behavior

No error is produced.

[aspizu]

Glob patterns e.g. costumes "*" should also error if any matched file is not an image file.

[aspizu]

This whole issue applies to sounds as well.