engineering-fundamentals

Engineering Fundamentals Review

"Code is read more than it is written. Write for the reader, not the machine."

When to Apply

Activate this skill when reviewing:

• Any code changes
• Function and variable naming
• Code organization and structure
• General refactoring decisions

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Review Checklist

Naming

• Descriptive: Can you understand the variable without context?
• No abbreviations: Are names spelled out? (user not usr)
• No generic names: No data, temp, info, stuff?
• Boolean prefix: Do booleans start with is, has, can, should?
• Function verbs: Do functions start with action verbs?

Function Design

• Single responsibility: Does each function do ONE thing?
• Size limit: Are functions under 20-30 lines?
• Parameter count: Are there fewer than 4 parameters?
• No side effects: Are pure functions actually pure?
• Early returns: Are guard clauses used instead of deep nesting?

Code Organization

• DRY: Is duplicated code extracted into functions?
• But not too DRY: Are abstractions justified (rule of three)?
• Cohesion: Are related things grouped together?
• Separation: Are unrelated things separated?

Comments & Documentation

• Why, not what: Do comments explain reasoning, not obvious code?
• No commented-out code: Is dead code deleted, not commented?
• JSDoc on public APIs: Are exported functions documented?

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Common Mistakes (Anti-Patterns)

1. Magic Numbers

❌ if (status === 2) { ... }
   setTimeout(callback, 86400000);

✅ const STATUS = { ACTIVE: 2, INACTIVE: 1 };
   if (status === STATUS.ACTIVE) { ... }

   const ONE_DAY_MS = 24 * 60 * 60 * 1000;
   setTimeout(callback, ONE_DAY_MS);

2. Unclear Naming

❌ const d = new Date();
   const temp = getUser();
   const flag = true;

✅ const createdAt = new Date();
   const currentUser = getUser();
   const isAuthenticated = true;