preflight

Preflight

Run before a production deploy, before pushing a release branch, or whenever auth or storage suddenly fails in production but works locally. It is an interactive check, not a CI gate.

Procedure

Run from the project root:

# 1. Literal \n inside a quoted env value (dotenv turns it into a real newline)
grep -nE '\\n"[[:space:]]*$' .env* 2>/dev/null

# 2. Trailing whitespace inside a quoted value
grep -nE '[[:space:]]+"$' .env* 2>/dev/null

# 3. Non-ASCII working directory with Next.js (the bundler can choke on it)
if [ -f package.json ] && jq -e '.dependencies.next // .devDependencies.next' package.json >/dev/null 2>&1; then
  pwd | LC_ALL=C grep -P '[^\x00-\x7F]' >/dev/null && echo "WARN: non-ASCII path + Next.js"
fi

# 4. Empty catch blocks (swallowed errors)
grep -rnE '\bcatch[[:space:]]*(\([^)]*\))?[[:space:]]*\{[[:space:]]*\}' src app pages 2>/dev/null | head -5

If jq or grep -P is missing on this machine, say so and skip that check rather than reporting a pass.

Output

One line per check, with file:line and a one-line fix for every failure:

preflight YYYY-MM-DD
[PASS] env: no literal \n in quoted values
[FAIL] env: .env.production:12 trailing whitespace inside quoted value
[PASS] path: ASCII-only working directory
[WARN] catch: src/api/upload.ts:42 empty catch block

Fixes

• Literal \n in a quoted value: put the value on one line. A real newline inside a JWT or signed URL corrupts it.
• Trailing whitespace inside the quotes: strip it; most parsers keep it and the API then rejects the token.
• Non-ASCII path with Next.js: move the project to an ASCII-only path.
• Empty catch {}: at minimum log the error; better, surface it to the caller.

When not to run

On a fresh repo with no env file yet, or as a CI gate (use a linter there).