Collapse consecutive if statements with the same condition

[Rich-Harris]

E.g. if you have two computed values with the same dependencies (REPL), the generated code looks like this:

function recompute ( state, newState, oldState, isInitial ) {
  if ( isInitial || ( 'a' in newState && differs( state.a, oldState.a ) ) ) {
    state.x = newState.x = template.computed.x( state.a );
  }
	
  if ( isInitial || ( 'a' in newState && differs( state.a, oldState.a ) ) ) {
    state.y = newState.y = template.computed.y( state.a );
  }
}

It could look like this:

function recompute ( state, newState, oldState, isInitial ) {
  if ( isInitial || ( 'a' in newState && differs( state.a, oldState.a ) ) ) {
    state.x = newState.x = template.computed.x( state.a );
    state.y = newState.y = template.computed.y( state.a );
  }
}

Separately, I've been wondering about doing away with isInitial and just having a block like this at the start of the constructor:

function App ( options ) {
  options = options || {};
  this._state = options.data || {};
  this._state.x = template.computed.x( state.a );
  this._state.y = template.computed.y( state.a );

  // ...
}

// instead of this:
function App ( options ) {
  options = options || {};
  this._state = options.data || {};
  recompute( this._state, this._state, {}, true );

  // ...
}

Slightly more code, but maybe slightly less work? Not sure about this trade-off.

[Rich-Harris]

fixed in 1.14