fix: validate required environment variables before startup

[alok-kumar0421]

Added a centralized validation step for required environment variables.

The app now checks for MONGO_URL, PORT, and REDIS_URL during initialization.
If any variable is missing, it logs a clear error and exits early, preventing unexpected runtime crashes in dependent modules.

Summary by CodeRabbit

• Chore
  • Application now validates required environment variables at startup and exits with an error if any are missing.

[vercel]

@alok-kumar0421 is attempting to deploy a commit to the Yash Pouranik's projects Team on Vercel.

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[coderabbitai]

📝 Walkthrough

Walkthrough

A new environment variable validation utility was added to enforce required configuration at server startup. The validation checks for MONGO_URL, PORT, and REDIS_URL, logging descriptive errors and exiting the process if any are missing.

Changes

Cohort / File(s)	Summary
Environment Validation backend/utils/validateEnv.js	New utility function that defines required environment variables (MONGO_URL, PORT, REDIS_URL), identifies missing variables, logs detailed errors for each missing variable, and exits the process with code 1 if validation fails.
Server Initialization backend/app.js	Integrated environment validation by importing and immediately invoking validateEnv after loading dotenv, ensuring environment checks occur before further server initialization.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Poem

🐰 A check at the start, before code takes flight,
Required variables gathered, all shining bright,
MONGO, PORT, REDIS—the trinity complete,
Or exit with haste when needs go unmet! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding environment variable validation before startup. It is concise, specific, and directly relates to the core functionality introduced in the changeset.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 2

🤖 Fix all issues with AI agents

In `@backend/utils/validateEnv.js`:
- Around line 1-11: The requiredEnvVars array in validateEnv (requiredEnvVars /
validateEnv) declares "PORT" mandatory while app.js still uses a fallback const
PORT = process.env.PORT || 1234, causing a contradiction; choose one approach
and make them consistent: either remove "PORT" from requiredEnvVars so
validateEnv won't exit when PORT is missing and keep the fallback in app.js, or
remove the || 1234 fallback in app.js and keep "PORT" in requiredEnvVars so the
app fails fast; update whichever file you change (requiredEnvVars list in
validateEnv or the PORT initialization in app.js) accordingly.
- Around line 3-11: The validateEnv function currently checks requiredEnvVars
unconditionally and exits the process, breaking tests; update validateEnv (or
its caller) to skip or relax validation when NODE_ENV === 'test' (or accept a
context flag) so tests that intentionally omit MONGO_URL/REDIS_URL won't call
process.exit(1). Locate validateEnv and the requiredEnvVars list and either add
a guard at the top of validateEnv (return early if process.env.NODE_ENV ===
'test') or allow validateEnv to accept an options param (e.g., {
allowMissingInTest: true }) and use that in app.js where NODE_ENV !== 'test' is
already checked; ensure any change references validateEnv and requiredEnvVars so
the test environment isn't forced to provide DB URLs.

🧹 Nitpick comments (1)

backend/utils/validateEnv.js (1)

4-4: Empty-string values pass silently.

!process.env[key] will catch undefined, but an env var set to an empty string ("") is also falsy and will be caught — which is good. However, a whitespace-only value like " " will slip through. If you want stricter validation, use .trim():

const missing = requiredEnvVars.filter((key) => !process.env[key]?.trim());

[yash-pouranik]

Thank you for the PR @alok-kumar0421 that solves #18

[alok-kumar0421]

Thank you!