diff --git a/app/Http/Controllers/StarTagsController.php b/app/Http/Controllers/StarTagsController.php
index 2bfcd586..2879ca68 100644
--- a/app/Http/Controllers/StarTagsController.php
+++ b/app/Http/Controllers/StarTagsController.php
@@ -12,16 +12,6 @@
 
 class StarTagsController extends Controller
 {
-    /**
-     * Display a listing of the resource.
-     *
-     * @return \Illuminate\Http\Response
-     */
-    public function index()
-    {
-        //
-    }
-
     /**
      * Store a newly created resource in storage.
      *
@@ -35,16 +25,25 @@ public function store(Request $request)
             'repos.*.nameWithOwner' => ['required', 'string'],
             'repos.*.url' => ['required', 'string', 'url'],
             'repos.*.description' => ['nullable', 'string'],
-            'tagId' => ['required', Rule::exists('tags', 'id')->where(function ($query) {
-                return $query->where('user_id', auth()->id());
-            }), ],
+            'tagId' => [
+                'required',
+                Rule::exists('tags', 'id')
+                    ->where(fn ($query) => $query->where('user_id', auth()->id())),
+            ],
         ]);
 
         $repos = $request->input('repos');
         $tagId = $request->input('tagId');
 
         foreach ($repos as $repo) {
-            $star = auth()->user()->stars()->firstOrCreate(['repo_id' => $repo['databaseId']], ['meta' => collect($repo)->except(['databaseId'])->toArray()]);
+            $star = auth()
+                ->user()
+                ->stars()
+                ->firstOrCreate(
+                    ['repo_id' => $repo['databaseId']],
+                    ['meta' => collect($repo)->except(['databaseId'])->toArray()]
+                );
+
             $star->tags()->syncWithoutDetaching([$tagId]);
         }
 
@@ -73,7 +72,13 @@ public function update(Request $request)
         $tags = $request->input('tags');
         $meta = $request->only(['nameWithOwner', 'url', 'description']);
 
-        $star = auth()->user()->stars()->firstOrCreate(['repo_id' => $repoId], ['meta' => $meta]);
+        $star = auth()
+            ->user()
+            ->stars()
+            ->firstOrCreate(
+                ['repo_id' => $repoId],
+                ['meta' => $meta]
+            );
 
         $ids = [];
 
diff --git a/tests/Feature/Controllers/StarTagsController/StoreTest.php b/tests/Feature/Controllers/StarTagsController/StoreTest.php
new file mode 100644
index 00000000..2c281035
--- /dev/null
+++ b/tests/Feature/Controllers/StarTagsController/StoreTest.php
@@ -0,0 +1,149 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\Tag;
+use App\Models\Star;
+
+it('redirects guests to the login page')
+    ->post('/stars/tag')
+    ->assertRedirect('/login');
+
+it('creates a new `Star` record + pivot entry for each repository passed to the request', function () {
+    $repoData = [
+        [
+            'databaseId' => 1234,
+            'nameWithOwner' => 'obsproject/obs-studio',
+            'url' => 'https://github.com/obsproject/obs-studio',
+        ],
+        [
+            'databaseId' => 5678,
+            'nameWithOwner' => 'stream-labs/desktop',
+            'url' => 'https://github.com/stream-labs/desktop',
+        ],
+    ];
+
+    $this->login();
+
+    $tag = Tag::factory()->create(['name' => 'Livestreaming', 'user_id' => auth()->id()]);
+
+    $this->assertDatabaseMissing('star_tag', ['tag_id' => $tag->id]);
+
+    $this
+        ->post(route('star.tags.store'), [
+            'repos' => $repoData,
+            'tagId' => $tag->id,
+        ])
+        ->assertRedirect(route('dashboard.show'));
+
+    foreach ($repoData as $repo) {
+        $this->assertDatabaseHas('stars', [
+            'repo_id' => $repo['databaseId'],
+            'meta' => collect($repo)->except(['databaseId'])->toJson(),
+        ]);
+
+        $this->assertDatabaseHas('star_tag', [
+            'tag_id' => $tag->id,
+            'star_id' => auth()->user()->stars()->where('repo_id', $repo['databaseId'])->first()->id,
+        ]);
+    }
+});
+
+it('doesn\'t create a new `Star` if it already exists for that user', function () {
+    $repoData = [
+        [
+            'databaseId' => 1234,
+            'nameWithOwner' => 'obsproject/obs-studio',
+            'url' => 'https://github.com/obsproject/obs-studio',
+        ],
+        [
+            'databaseId' => 5678,
+            'nameWithOwner' => 'stream-labs/desktop',
+            'url' => 'https://github.com/stream-labs/desktop',
+        ],
+    ];
+
+    $this->login();
+
+    $tag = Tag::factory()->create(['name' => 'Livestreaming', 'user_id' => auth()->id()]);
+    Star::factory()->create(['repo_id' => 1234, 'user_id' => auth()->id()]);
+
+    $this
+        ->post(route('star.tags.store'), [
+            'repos' => $repoData,
+            'tagId' => $tag->id,
+        ]);
+
+    expect(auth()->user()->stars()->count())->toBe(2);
+    expect(auth()->user()->stars()->where('repo_id', 1234)->count())->toBe(1);
+});
+
+describe('Validating repository data', function () {
+    beforeEach(function () {
+        $this->login();
+
+        $this->tag = Tag::factory()->create(['name' => 'Laravel', 'user_id' => auth()->id()]);
+        $this->meta = [
+            'databaseId' => 583823,
+            'nameWithOwner' => 'astralapp/astral',
+            'url' => 'https://github.com/astralapp/astral',
+        ];
+        $this->metaWithoutDatabaseId = collect($this->meta)->except(['databaseId'])->toArray();
+        $this->metaWithoutNameWithOwner = collect($this->meta)->except(['nameWithOwner'])->toArray();
+        $this->metaWithoutUrl = collect($this->meta)->except(['url'])->toArray();
+    });
+
+    it('requires an array of repository data', function ($badData, array|string $errors) {
+        $this
+            ->post(route('star.tags.store'), ['tagId' => $this->tag->id, 'repos' => $badData])
+            ->assertInvalid($errors);
+    })->with([
+        [[], 'repos'],
+        [null, 'repos'],
+        [1234, 'repos'],
+        ['[]', 'repos'],
+    ]);
+
+    it('requires a valid `databaseId` field for each repository passed', function ($badData, array|string $errors) {
+        $this
+            ->post(route('star.tags.store'), ['tagId' => $this->tag->id, 'repos' => $badData])
+            ->assertInvalid($errors);
+    })->with([
+        fn () => [[$this->metaWithoutDatabaseId], 'repos.0.databaseId'],
+        fn () => [[[...$this->metaWithoutDatabaseId, 'databaseId' => 'foobar']], 'repos.0.databaseId'],
+        fn () => [[[...$this->metaWithoutDatabaseId, 'databaseId' => null]], 'repos.0.databaseId'],
+        fn () => [[[...$this->metaWithoutDatabaseId, 'databaseId' => []]], 'repos.0.databaseId'],
+    ]);
+
+    it('requires a valid `nameWithOwner` field for each repository passed', function ($badData, array|string $errors) {
+        $this
+            ->post(route('star.tags.store'), ['tagId' => $this->tag->id, 'repos' => $badData])
+            ->assertInvalid($errors);
+    })->with([
+        fn () => [[$this->metaWithoutNameWithOwner], 'repos.0.nameWithOwner'],
+        fn () => [[[...$this->metaWithoutNameWithOwner, 'nameWithOwner' => 12345]], 'repos.0.nameWithOwner'],
+        fn () => [[[...$this->metaWithoutNameWithOwner, 'nameWithOwner' => null]], 'repos.0.nameWithOwner'],
+        fn () => [[[...$this->metaWithoutNameWithOwner, 'nameWithOwner' => []]], 'repos.0.nameWithOwner'],
+    ]);
+
+    it('requires a valid `url` field for each repository passed', function ($badData, array|string $errors) {
+        $this
+            ->post(route('star.tags.store'), ['tagId' => $this->tag->id, 'repos' => $badData])
+            ->assertInvalid($errors);
+    })->with([
+        fn () => [[$this->metaWithoutUrl], 'repos.0.url'],
+        fn () => [[[...$this->metaWithoutUrl, 'url' => 12345]], 'repos.0.url'],
+        fn () => [[[...$this->metaWithoutUrl, 'url' => 'not-a-url-string']], 'repos.0.url'],
+        fn () => [[[...$this->metaWithoutUrl, 'url' => null]], 'repos.0.url'],
+        fn () => [[[...$this->metaWithoutUrl, 'url' => []]], 'repos.0.url'],
+    ]);
+
+    it('validates the `description` field if present', function ($badData, array|string $errors) {
+        $this
+            ->post(route('star.tags.store'), ['tagId' => $this->tag->id, 'repos' => $badData])
+            ->assertInvalid($errors);
+    })->with([
+        fn () => [[[...$this->metaWithoutUrl, 'description' => 12345]], 'repos.0.description'],
+        fn () => [[[...$this->metaWithoutUrl, 'description' => []]], 'repos.0.description'],
+    ]);
+});