no-unenclosed-multiline-block.md

no-unenclosed-multiline-block

Curly braces can be omitted from a one-line block, such as with an if statement or for loop, but doing so can be misleading and induce bugs.

This rule raises an issue when the whitespacing of the lines after a one line block indicates an intent to include those lines in the block, but the omission of curly braces means the lines will be unconditionally executed once.

Noncompliant Code Example

if (condition)
  firstActionInBlock();
  secondAction();  // Noncompliant; executed unconditionally
thirdAction();

if (condition) firstActionInBlock(); secondAction();  // Noncompliant; secondAction executed unconditionally

if (condition) firstActionInBlock();  // Noncompliant
  secondAction();  // Executed unconditionally

if (condition); secondAction();  // Noncompliant; secondAction executed unconditionally

let str: string|null = null;
for (let i = 0; i < array.length; i++) 
  str = array[i];
  doTheThing(str);  // Noncompliant; executed only on last array element

Compliant Solution

if (condition) {
  firstActionInBlock();
  secondAction();
}
thirdAction();

str: string|null = null;
for (let i = 0; i < array.length; i++) {
  str = array[i];
  doTheThing(str);
}