Username Suggestion Function Breakdown

Function Declaration

export async function getAvailableUsernameSuggestions(base: string, count = 3, maxTries = 10) {

What it does:

• Declares an async function (can wait for database operations)
• Takes 3 parameters:
  • base: the starting username (like "john")
  • count: how many suggestions to return (default: 3)
  • maxTries: maximum attempts to find usernames (default: 10)

---

Initialize Storage

const suggestions: string[] = [];

What it does:

• Creates an empty array to store the available usernames we find
• TypeScript notation : string[] means it only holds strings

---

Main Loop

for (let i = 1; suggestions.length < count && i < maxTries; i++) {

What it does:

• Starts a loop with counter i = 1
• Continues while BOTH conditions are true:
  • We haven't found enough suggestions yet (suggestions.length < count)
  • We haven't exceeded our attempt limit (i < maxTries)
• Increments i after each attempt

---

Generate Username Candidate

const candidate = `${base}${i}`;

What it does:

• Creates a potential username by combining the base with the current number
• Example: if base = "john" and i = 1, then candidate = "john1"

---

Check Database

const exists = await db.user.findUnique({ where: { username: candidate } });

What it does:

• Searches the database to see if this username already exists
• await pauses the function until the database responds
• Returns the user record if found, or null if not found

---

Add to Suggestions

if (!exists) suggestions.push(candidate);

What it does:

• If the username doesn't exist in the database (!exists means "not exists")
• Adds the available username to our suggestions array

---

Return Results

return suggestions;

What it does:

• Returns the array of available usernames we found

---

Example Usage

If you call getAvailableUsernameSuggestions("sarah", 3):

1. Try "sarah1" → Check database → If available, add to suggestions
2. Try "sarah2" → Check database → If available, add to suggestions
3. Try "sarah3" → Check database → If available, add to suggestions
4. Continue until we have 3 suggestions OR we've tried 10 times

Possible result: ["sarah1", "sarah3", "sarah7"] (if "sarah2" was taken)

Key Features

• Smart stopping: Stops when it finds enough suggestions, doesn't waste time
• Prevents infinite loops: Won't try forever if most usernames are taken
• Efficient: Only checks database for usernames that might work
• Flexible: You can customize how many suggestions and how many attempts