Review Codebase for Improper Prisma `where` Usage

Created by: deepakduggirala

Description:

We've identified a potential issue where undefined values in Prisma where conditions are causing unintended behavior. This can lead to queries returning unexpected results, including retrieving unintended records when a filter is missing.

Problem Explanation:

Current Behavior:

• If a value in the where clause is undefined, Prisma removes the entire condition instead of treating it as NULL or an ignored filter.
• If a value is explicitly null, Prisma correctly applies WHERE key IS NULL.

Example of Unexpected Behavior:

const value = undefined;

const result = await prisma.user.findFirst({
  where: { email: value }
});

What actually happens?
Prisma removes the where clause entirely, making the query equivalent to:

SELECT * FROM "User" LIMIT 1;

This could return any user, which is not the expected behavior.

---

const value = null;

const result = await prisma.user.findFirst({
  where: { email: value }
});

What happens here?
Prisma translates it to:

SELECT * FROM "User" WHERE "email" IS NULL LIMIT 1;

This behaves as expected, returning only users with NULL emails.

Impact of This Issue:

• Unexpected Query Behavior: If filters are dynamically set, unintended records may be retrieved if a value happens to be undefined.
• Security Risk: If critical filters are unintentionally removed, data exposure issues may arise.
• Logical Errors: If business logic assumes a filter is applied when it isn't, incorrect results may be used in application decisions.

Tasks:

1. Audit the codebase for all instances of prisma.findFirst, findMany, findUnique, deleteMany, or any other query using where.
2. Ensure filters are correctly applied, using one of the following approaches:
   • Explicitly construct the where clause only if values are defined:

     const whereClause: any = {};
     if (value !== undefined) whereClause.email = value;
     
     const result = await prisma.user.findFirst({ where: whereClause });

   • Use ?? null to ensure Prisma doesn’t remove the condition:

     const result = await prisma.user.findFirst({
       where: { email: value ?? null }
     });

3. Write tests to ensure that undefined values do not cause Prisma to drop where conditions unexpectedly.
4. Document the best practice for handling optional filters in Prisma queries.

Priority: High

This issue could lead to incorrect data retrieval and security concerns. Fixing it ensures predictable query behavior across the application.