fix(prisma): throw clear error when DATABASE_URL is missing

[prathamesh04]

What does this PR do?

Adds an early validation in the Prisma client initialization that throws a descriptive error when DATABASE_URL is not set.

Previously, when DATABASE_URL was missing, the Prisma client attempted to connect with an empty string, resulting in a cryptic PostgreSQL connection error that was confusing for new contributors and self-hosters.

Changes

• packages/prisma/index.ts: Replaced process.env.DATABASE_URL || "" with an explicit check that throws a clear error message with an example connection string.

Before

Error: Error in PostgreSQL connection: error connecting to server: Connection refused

After

Error: DATABASE_URL environment variable is missing. Please set it in your .env file. Example: DATABASE_URL="postgresql://user:password@localhost:5432/calendso"

Closes #24485

cc @bandhan-majumder

[github-actions]

Welcome to Cal.diy, @prathamesh04! Thanks for opening this pull request.

A few things to keep in mind:

• This is Cal.diy, not Cal.com. Cal.diy is a community-driven, fully open-source fork of Cal.com licensed under MIT. Your changes here will be part of Cal.diy — they will not be deployed to the Cal.com production app.
• Please review our Contributing Guidelines if you haven't already.
• Make sure your PR title follows the Conventional Commits format.

A maintainer will review your PR soon. Thanks for contributing!

[coderabbitai]

📝 Walkthrough

Walkthrough

Prisma connection string initialization now requires process.env.DATABASE_URL. When the variable is missing, module initialization throws an error with guidance instead of defaulting to an empty string, preventing downstream pool and adapter setup from proceeding with an invalid connection string.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly matches the main change: adding a clear error when DATABASE_URL is missing.
Description check	✅ Passed	The description is directly related to the Prisma validation change and the missing DATABASE_URL fix.
Linked Issues check	✅ Passed	The change satisfies #24485 by failing early with a descriptive missing-DATABASE_URL error instead of a cryptic crash.
Out of Scope Changes check	✅ Passed	No out-of-scope changes are indicated; the patch stays focused on DATABASE_URL validation in Prisma initialization.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/prisma/index.ts`:
- Around line 12-15: Replace the plain Error thrown in the missing
connectionString validation with ErrorWithCode, supplying the repository’s
standard configuration error code while preserving the existing DATABASE_URL
guidance message.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: b8a8f5fa-0a7b-4222-bf89-0f939e0df48c

📥 Commits

Reviewing files that changed from the base of the PR and between f004349 and 3e955bf.

📒 Files selected for processing (1)

• packages/prisma/index.ts

[coderabbitai]

📐 Maintainability & Code Quality | 🟠 Major | ⚡ Quick win

Use ErrorWithCode for this non-tRPC configuration error.

This file is outside tRPC, so throwing new Error violates the repository error-handling contract. Replace it with ErrorWithCode, including the project’s standard error code, while preserving the guidance message.

As per coding guidelines, use ErrorWithCode for errors in non-tRPC files.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@packages/prisma/index.ts` around lines 12 - 15, Replace the plain Error
thrown in the missing connectionString validation with ErrorWithCode, supplying
the repository’s standard configuration error code while preserving the existing
DATABASE_URL guidance message.

Source: Coding guidelines