Indentation

When control statements (if, while etc.) are too long or exceed the maximum line length, each (grouped) condition could be put into a new line. The logical operator should begin the line. Requiring operators at the beginning of the line keeps the operators aligned and follows a pattern similar to method chaining. This also improves readability by making it easier to visually follow complex logic.

Examples

⇣ Incorrect code for this rule:

if ((season === "winter" || snowflakes === 20) && aVeryLongMethodNameThatExceedsTheLineLength() && anotherLongNamedMethod()) {
  snow();
}

if (snowflakes === 20 &&
  season === "winter") {
  snow();
}

if (snowflakes === 20
  && season === "winter") {
  snow();
}

if (
  snowflakes === 20 &&
  season === "winter"
) {
  snow();
}

⇡ Correct code for this rule:

if (snowflakes === 20 && season === "winter") {
  snow();
}

if (
  (snowflakes === 20 || season === "winter") &&
  aVeryLongMethodNameThatExceedsTheLineLength() &&
  anotherLongNamedMethod()
) {
  snow();
}

if (snowflakes === 20 && season === "winter") {
  snow();
}

Selection Operators

Prefer to use control statements instead of selection operators.

Examples

⇣ Incorrect code for this rule:

!hasSnow && buildSnowblocks();

⇡ Correct code for this rule:

if (!hasSnow) {
  buildSnowblocks();
}