[NEW FEAT.] Add URL validation process to avoid Google Apps Script's Exception: Invalid argument: url Error

[ttsukagoshi]

Discussed in #323

Background

There are several ways in which you can specify a spreadsheet by its URL:

1. The basic format: https://docs.google.com/spreadsheets/d/<sheet-id>/edit#gid=0
2. The basic format without specifying the worksheet ID gid: https://docs.google.com/spreadsheets/d/<sheet-id>/edit
3. Pattern 2 without edit: https://docs.google.com/spreadsheets/d/<sheet-id>/
4. Pattern 3 without the trailing /: https://docs.google.com/spreadsheets/d/<sheet-id>

Patterns 1 - 4 all work fine if you are simply entering the URL in your browser, but it is not so in Google Apps Script (GAS), which is the underlying architecture behind Group Merge. In GAS, Patterns 1 - 3 are acceptable, while Pattern 4 returns the error in the title.

Current workaround

Following the How-to-Use steps in the add-on's webpage would be the easiest way to avoid it; you can let the add-on enter the spreadsheet URL automatically at step 4.

Adding URL Validation

Since the add-on allows users to enter the spreadsheet URL freely, it would be better to have a validation step to check the URL format and add /edit to the end of the URL when necessary to avoid the error.