Internet Explorer < 9 compatibility mode?

[Bartvds]

Is there a way to run spectacular on IE < 9 ?

Sadly clients still need this so I was wondering the Object.defineProperty is used for critical functionality or some sort of compatibility mode with reduced feature could work.

[abe33]

Hi @Bartvds, and sorry for the late reply,

There's at least the given/subject feature that will break without Object.defineProperty. Using a getter allow to have both a property like syntax and lazy init. Using a function instead will break the syntax (and all previous tests), and I'm not really fond of this solution. The other way is to replace the getters with simple properties, but in that case there's at least two issues that remains:

Actually you can do this:

context 'level 1', ->
  given 'bar', -> new Bar @foo
  given 'foo', -> {}

or this:

context 'level 1', ->
  given 'bar', -> new Bar @foo

  context 'level 2-1', ->
    given 'foo', -> {}

  context 'level 2-2', ->
    given 'foo', -> {property: 'value'}

Both cases will break using properties instead of getters as foo will not exist yet when bar is created.

There's a second situation that will no longer be possible with properties:

context 'level 1', ->
  given 'foo', -> {}
  given 'bar', -> new Bar @foo

  context 'level 2', ->
    given 'foo', -> {property: 'value'}

Actually, bar will be created with {property: 'value'} in the second context, but with properties it will always receive {}. There's a solution to that problem that involve storing the order in which given/subject blocks are defined and replace the block at the given position in case the same name is passed to given/subject, but it will still require to declare given/subject in a specific order.

These 2 issues could be addressed with a compatibility mode. It remains all the Spectacular classes that uses getters or setters and that will have to be rewritten using plain functions instead. It's not impossible but frankly I don't like the idea of changing the design midway to support an obsolete browser whose share will only decrease with time (there's already plenty of frameworks that perform well in IE<9 and this project really started as a playground for ES5 stuff and TDD learning an not really for world conquest). Ideally, I would prefer an automated solution that convert these at compile time but I have yet to figure how to do this. Maybe with some kind of static analysis, but anyway it's not a trivial change.

I leave this issue open for anyone with advice or just for discussion.

Regards