Blocks

  • 16.1 Use braces with all multi-line blocks. eslint: nonblock-statement-body-position

    1. // bad
    2. if (test)
    3.   return false;
    5. // good
    6. if (test) return false;
    8. // good
    9. if (test) {
    10.   return false;
    11. }
    13. // bad
    14. function foo() { return false; }
    16. // good
    17. function bar() {
    18.   return false;
    19. }

  • 16.2 If you’re using multi-line blocks with if and else, put else on the same line as your if block’s closing brace. eslint: brace-style

    1. // bad
    2. if (test) {
    3.   thing1();
    4.   thing2();
    5. }
    6. else {
    7.   thing3();
    8. }
    10. // good
    11. if (test) {
    12.   thing1();
    13.   thing2();
    14. } else {
    15.   thing3();
    16. }

  • 16.3 If an if block always executes a return statement, the subsequent else block is unnecessary. A return in an else if block following an if block that contains a return can be separated into multiple if blocks. eslint: no-else-return

    1. // bad
    2. function foo() {
    3.   if (x) {
    4.     return x;
    5.   } else {
    6.     return y;
    7.   }
    8. }
    10. // bad
    11. function cats() {
    12.   if (x) {
    13.     return x;
    14.   } else if (y) {
    15.     return y;
    16.   }
    17. }
    19. // bad
    20. function dogs() {
    21.   if (x) {
    22.     return x;
    23.   } else {
    24.     if (y) {
    25.       return y;
    26.     }
    27.   }
    28. }
    30. // good
    31. function foo() {
    32.   if (x) {
    33.     return x;
    34.   }
    36.   return y;
    37. }
    39. // good
    40. function cats() {
    41.   if (x) {
    42.     return x;
    43.   }
    45.   if (y) {
    46.     return y;
    47.   }
    48. }
    50. // good
    51. function dogs(x) {
    52.   if (x) {
    53.     if (z) {
    54.       return y;
    55.     }
    56.   } else {
    57.     return z;
    58.   }
    59. }