AgentSkillsCN

use-guard-clauses

在编写 TypeScript 函数时，使用 guard clause（提前返回）来避免 if 语句中的深层嵌套。

SKILL.md
--- frontmatter
name: use-guard-clauses
description: Use guard clauses (early returns) to avoid deep nesting in if statements when writing TypeScript functions.

Use Guard Clauses

Pattern

Return early from functions to avoid nested if statements.

✅ Good (Guard Clauses)

typescript
function processFile(file: File | null): string | null {
  if (!file) return null;
  if (file.size === 0) return null;
  if (!file.name.endsWith(".mp3")) return null;

  return transcribeFile(file);
}

❌ Bad (Nested Ifs)

typescript
function processFile(file: File | null): string | null {
  if (file) {
    if (file.size > 0) {
      if (file.name.endsWith(".mp3")) {
        return transcribeFile(file);
      }
    }
  }
  return null;
}

When to Use

  • •Functions with multiple validation conditions
  • •Error checking before main logic
  • •Null/undefined checks
  • •Permission/authentication checks

Benefits

  • •Flatter code structure
  • •Easier to read and maintain
  • •Clearer error paths
  • •Reduces cognitive load