printer-status-errors.md

Printer Status And Media Errors

This project now checks printer status before and after each print job and throws user-facing error messages when the printer reports an issue.

What Is Checked

GenericPrinter.print(job) performs:

1. A pre-flight status request before sending raster data.
2. A post-print status request after sending the final print command.

If either status response reports an error, printing fails with a descriptive Error.

User-Facing Error Messages

The printer status flags are mapped to friendly messages, including:

• REPLACE_MEDIA:
  • Example: Loaded media mismatch: printer has 24mm tape, but this job expects 9mm tape. Load 9mm tape and retry.
• NO_MEDIA:
  • No tape is loaded. Insert a tape cassette and try again.
• COVER_OPEN:
  • Printer cover is open. Close the cover and try again.
• CUTTER_JAM:
  • Printer cutter jam detected. Clear the jam and try again.
• OVERHEATING:
  • Printer is overheating. Let it cool down, then try again.
• WEAK_BATTERY:
  • Printer battery is low. Charge or power the printer and try again.

There is also a media-width/type mismatch check against the expected job media, even when a specific media error flag is not set.

Where It Is Implemented

• Status parsing and message mapping: src/printers.mjs
• Status constants: src/constants.mjs
• Coverage tests: test/printers.test.mjs

UI Behavior

The demo UI already surfaces thrown Error.message strings, so these messages are shown to the user without additional UI changes.