Seeding is Hard

May 24th, 2018 Code , Laravel , PHP

We've all been there... banging our heads against a wall for 20 minutes wondering why our app isn't working before we realize we forgot to seed our database when running migrations. Okay, easy fix:

$ php artisan migrate --seed
Migration table created successfully.
Migrating: 1996_02_27_123456_create_pokemon_table
Migrated:  1996_02_27_123456_create_pokemon_table
Seeding: PokemonSeederReflectionException : Class PokemonSeeder does not exist

Sigh... okay. I should have remembered to refresh the the autoload file first. My bad.

$ composer dump-autoload
$ php artisan migrate --seed
Nothing to migrate.
Seeding: PokemonSeederIlluminate\Database\QueryException  : SQLSTATE[23000]: Integrity constraint violation: 19 UNIQUE constraint failed: pokemon.id (SQL: insert into "pokemon" ("id", "name", "description") values (25, Pikachu, Whenever Pikachu comes across something new, it blasts it with a jolt of electricity.))

(╯°□°)╯︵ ┻━┻

Ugh... maybe the fix isn't as easy as I thought. I must have had some left over data there. I'm pretty sure that data is old so I'll just refresh the database.

$ php artisan migrate:fresh --seed
Dropped all tables successfully.
Migration table created successfully.
Migrating: 1996_02_27_123456_create_pokemon_table
Migrated:  1996_02_27_123456_create_pokemon_table
Seeding: PokemonSeeder

Finally things are going my way. ┬─┬ノ( º _ ºノ)

However, I should make a mental note to run the seeds individually on prod since we can't just refresh the data there. I wont forget... hopefully.

Now to make sure the tests are passing.

$ phpunit 
PHPUnit 7.1.5 by Sebastian Bergmann and contributors

...................F.                                  20 / 20 (100%)

Time: 1.33 minutes, Memory: 40.00MB

There was 1 failure:

1) Tests\Feature\PokemonTest::test_it_can_retrieve_a_pokemon_by_id
Invalid JSON was returned from the route.

┻━┻ ︵ヽ(`Д´)ノ︵ ┻━┻

In the aftermath historians identified that the tests failed due to missing $this->seed('PokemonSeeder').

The solution: Seed your initial data in your migrations.

<?php

use App\Pokemon;
use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreatePokemonTable extends Migration
{
    /** @var array Array of Pokemon */
    protected $pokemon = [
        [1, 'Bulbasaur', 'Bulbasaur can be seen napping in bright sunlight.'],
        [2, 'Ivysaur', "There is a bud on this Pokémon's back."],
        [3, 'Venusaur', "There is a large flower on Venusaur's back."]
        // ...
    ];

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('pokemon', function (Blueprint $table) {
            $table->increments('id');
            $table->string('name')->unique();
            $table->string('description');
            $table->timestamps();
        });

        $this->seed();
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('pokemon');
    }

    /**
     * Seed the pokemon table.
     *
     * @return void
     */
    protected function seed()
    {
        $pokemon = collect($this->pokemon)->map(function ($pokemon) {
            return array_combine(['id', 'name', 'description'], $pokemon);
        });

        Pokemon::insert($pokemon->toArray());
    }
}

With this, all the above troubles are alleviated and all you have to do is remember to run artisan migrate. This simple and elegant solution has several benefits:

  • Guarantees data is seeded during artisan migrate (without --seed)
  • Prevents accidental re-seeding on subsequent migrations
  • Eliminates the need for $this->seed() in your test cases
  • Avoids the annoying Class does not exist errors