fix: update slug size after 2nd attempt

app/controllers/link.cr

@@ -27,12 +27,14 @@ module App::Controllers::Link
       link.url = url
       link.user = user
 
+      attempts = 0
       loop do
-        slug = Random::Secure.urlsafe_base64(5).gsub(/[^a-zA-Z0-9]/, "")
-        if !Database.get_by(Link, slug: slug)
+        slug = Random::Secure.urlsafe_base64(attempts >= 2 ? 6 : 5).gsub(/[^a-zA-Z0-9]/, "")
+        unless Database.get_by(Link, slug: slug)
           link.slug = slug
           break
         end
+        attempts += 1
       end
 
       changeset = Database.insert(link)

db/migrations/20240714215409_update_slug_size_links.sql

@@ -0,0 +1,49 @@
+-- +micrate Up
+-- SQL in section 'Up' is executed when this migration is applied
+
+-- Step 1: Create a new table with the desired column type
+CREATE TABLE links_new (
+  id TEXT PRIMARY KEY NOT NULL,
+  user_id TEXT NOT NULL,
+  slug VARCHAR(8) UNIQUE NOT NULL,
+  url TEXT NOT NULL,
+  created_at INTEGER DEFAULT CURRENT_TIMESTAMP NOT NULL,
+  updated_at INTEGER DEFAULT CURRENT_TIMESTAMP NOT NULL,
+
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+
+-- Step 2: Copy data from the old table to the new table
+INSERT INTO links_new (id, user_id, slug, url, created_at, updated_at)
+SELECT id, user_id, slug, url, created_at, updated_at FROM links;
+
+-- Step 3: Drop the old table
+DROP TABLE links;
+
+-- Step 4: Rename the new table to the old table's name
+ALTER TABLE links_new RENAME TO links;
+
+-- +micrate Down
+-- SQL section 'Down' is executed when this migration is rolled back
+
+-- Step 1: Create a new table with the original column type
+CREATE TABLE links_old (
+  id TEXT PRIMARY KEY NOT NULL,
+  user_id TEXT NOT NULL,
+  slug VARCHAR(4) UNIQUE NOT NULL,
+  url TEXT NOT NULL,
+  created_at INTEGER DEFAULT CURRENT_TIMESTAMP NOT NULL,
+  updated_at INTEGER DEFAULT CURRENT_TIMESTAMP NOT NULL,
+
+  FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+
+-- Step 2: Copy data from the current table to the old table
+INSERT INTO links_old (id, user_id, slug, url, created_at, updated_at)
+SELECT id, user_id, substr(slug, 1, 4), url, created_at, updated_at FROM links;
+
+-- Step 3: Drop the current table
+DROP TABLE links;
+
+-- Step 4: Rename the old table to the current table's name
+ALTER TABLE links_old RENAME TO links;