Crazy sort using eval

sortBy-spec.coffee

describe "#sortBy", ->

  it "sorts on simple props", ->
    sorted   = [ {name: "bar"}, {name: "baz"}, {name: "foo"} ]
    unsorted = [ {name: "foo"}, {name: "bar"}, {name: "baz"} ]
  
    expect(unsorted.sort(sortBy("name"))).toEqual(sorted)
  
  it "sorts in nested objects", ->
    unsorted = [ {name: first: "foo"}, {name: first: "bar"}, {name: first: "baz"} ]
    sorted   = [ {name: first: "bar"}, {name: first: "baz"}, {name: first: "foo"} ]
  
    expect(unsorted.sort(sortBy("name.first"))).toEqual(sorted)
  
  it "sorts by function output", ->
    foo = -> "foo"
    bar = -> "bar"
    baz = -> "baz"
  
    unsorted = [ {name: foo}, {name: bar}, {name: baz} ]
    sorted   = [ {name: bar}, {name: baz}, {name: foo} ]
  
    expect(unsorted.sort(sortBy("name()"))).toEqual(sorted)

sortBy.coffee

sortBy: (prop) ->
  (a, b) ->
    if eval("a.#{prop} > b.#{prop}")
       1
    else if eval("a.#{prop} < b.#{prop}")
      -1
    else
       0