Prevent duplicate migrations when running telescope:install

[JoshSalway]

Summary

Running telescope:install multiple times creates duplicate migration files with different timestamps, causing "table already exists" errors on php artisan migrate.

Fixes #1589

Prior attempts

This issue has been submitted twice before, and both were closed:

• fix: prevent duplicate migrations on telescope:install #1634 (Sept 2025) — Closed by Taylor: "need to be very careful regarding the amount of code we include"
• hotfix: prevent duplicate migration creation during telescope:install. #1678 (Jan 2026) — Closed by Taylor: "lacks sufficient explanation, tests, or both"

This PR directly addresses both concerns.

Problem

Each run of telescope:install publishes migration files with fresh timestamps. After running it twice:

database/migrations/2026_03_19_000000_create_telescope_entries_table.php
database/migrations/2026_03_19_000001_create_telescope_entries_table.php

Running php artisan migrate then fails:

SQLSTATE: Table 'telescope_entries' already exists

This commonly happens when developers re-run the install command after pulling updates or when setting up a project from scratch with existing migrations.

Solution

Addressing #1634 (code volume concern): The entire fix is a single migrationExists() method — one glob() call using the *_create_telescope_entries_table.php pattern. This is the same pattern Laravel's own framework uses in its install commands (e.g., Pulse, Pennant). The check is added with a single if guard around the existing vendor:publish call. No new dependencies, no architectural changes.

Addressing #1678 (lacking explanation and tests): This PR includes 3 automated tests covering the detection logic:

1. test_migration_exists_returns_false_when_no_migration_present — fresh install proceeds normally
2. test_migration_exists_returns_true_when_migration_present — repeat install skips migration publishing
3. test_migration_exists_returns_false_when_directory_does_not_exist — edge case where migrations directory doesn't exist yet

Before / After

Scenario	Before	After
First telescope:install	Migration published	Migration published (unchanged)
Second telescope:install	Duplicate migration created	Migration publishing skipped
php artisan migrate after double install	"table already exists" error	Runs cleanly

Why this doesn't break anything

• The check only runs during telescope:install, not during normal application execution
• If the migration file exists (regardless of timestamp prefix), publishing is skipped — this is purely additive
• If the migrations directory doesn't exist yet, the check returns false and publishing proceeds as normal
• The glob pattern matches Laravel's own convention used across first-party packages

[github-actions]

Thanks for submitting a PR!

Note that draft PRs are not reviewed. If you would like a review, please mark your pull request as ready for review in the GitHub user interface.

Pull requests that are abandoned in draft may be closed due to inactivity.