Code Style

All code checked in to the roster must conform to the code style guide. Please make sure this is true before you send it for review to save everyone time.

Core

In general, we use the Google Javascript Style Guide, with the following reiterations / additions.

Highlights

• Indent with spaces, not tabs
• 2 spaces per indent
• 80 characters per line
• Use single quote, ', or backtick for string literals, not double-quote, ".
• K&R-style brackets:

  function foo() {
    // ...
  }

• Two indents when breaking a line. Break lines at highest syntactic level possible.

  const foo =
      reallyLongObjectName.doReallyLongMethod(
          param1, param2, param3);

• Spaces after control flow keywords (if, when, else)

  if (foo) {
    // ...
  } else {
    // ...
  }

• Spaces on both sides of arithmetic operators

  // Yes
  let foo = a + b / 3;
  // No
  let foo = a+b/3;

Typescript additions

• Type annotations are of the form symbol: type.

  // Yes
  const foo: Bar;
  
  // No
  const foo:Bar;
  const foo : Bar;
  const foo :Bar;

• Type union or intersection operators have spaces on both sides:

  // Yes
  const foo: Bar | undefined;
  
  // No
  const foo: Bar|undefined;

• Functions whose arguments/return type cannot fit on one line should put one parameter on each line, with the closing brace/return type on its own line as well. Use trailing commas for the parameter list.

  function veryLongFunctionHeader(
      param1: type1,
      param2: type2,
      param3: type3,
      param4: type4,
  ): number | undefined  {
    // ...
  }

Modifications

• When using chained promise calls, do not indent chained .then() and .catch() calls

  return Promise.resolve()
  .then(() => {
    console.log('First step');
  })
  .catch(e => {
    console.error(e.message);
  });