Show evaluated expr when @test isequal(...) fails

[omus]

Support showing the evaluated version of the expression when using @test with isequal:

julia> using Base.Test

julia> x, y = 1, 2
(1, 2)

julia> @test isequal(x, y)
Test Failed
  Expression: isequal(x, y)
   Evaluated: isequal(1, 2)
ERROR: There was an error during testing

[tkelman]

ex.args[1] in (:isequal, :isapprox, :≈) would also be useful if that comes out looking right

[omus]

The ≈ operator is evaluated already. Unfortunately it isn't quite right:

julia> @test x ≈ y
Test Failed
  Expression: x ≈ y
   Evaluated: 1 isapprox 2

[omus]

Seems like this wasn't tested very thoroughly:

julia> @test x ≈ y ≈ z
Test Failed
  Expression: $(Expr(:escape, :x)) $(Expr(:escape, :≈)) $(Expr(:escape, :y)) $(Expr(:escape, :≈)) $(Expr(:escape, :z))
   Evaluated: 1 isapprox 2 isapprox 3

I'll try to address this.

[omus]

Addressed all of the above mentioned issues.

[omus]

Changes now include:

• Corrected @test x == y == z shown expression
• Corrected @test x ≈ y shown evaluated expression
• Added showing evaluated expression of @test isequal(...) and @test isapprox(...)
• Lots of tests

[KristofferC]

Any commits that can be backported?

[omus]

Any commits that can be backported?

I'll break this into two PRs which separates the new features from the bugfixes

[omus]

I couldn't make a clean separation between the fixes and the features. PR #22315 contains just the fixes and this PR extends that work with the features.

[omus]

Sibling PR #22315 has been merged. I've rebased this PR which now makes the diff understandable. Reviews are welcome.

[omus]

I think this is good to go. I'll merge at the end of JuliaCon unless there are objections.

[nalimilan]

This seems to have broken StatsBase tests. MWE:

julia> @test isapprox(1, 1, atol=0)
Error During Test
  Test threw an exception of type MethodError
  Expression: isapprox(1, 1, atol=0)
  MethodError: no method matching Expr(::Symbol, ::Base.#isapprox, ::Int64, ::Int64; atol=0)
  Closest candidates are:
    Expr(::ANY...) at boot.jl:193 got unsupported keyword argument "atol"
  Stacktrace:
   [1] eval(::Module, ::Any) at ./boot.jl:236
   [2] eval_user_input(::Any, ::Base.REPL.REPLBackend) at ./repl/REPL.jl:67
   [3] macro expansion at ./repl/REPL.jl:98 [inlined]
   [4] (::Base.REPL.##1#2{Base.REPL.REPLBackend})() at ./event.jl:73
ERROR: There was an error during testing

[omus]

I'll look into it.

[omus]

I just noticed that I need to some additional work to get splatting to work with the call syntax:

julia> @test isequal((1,1)...)
Error During Test
  Test threw an exception of type BoundsError
  Expression: isequal((1, 1)...)
  BoundsError: attempt to access 3-element Array{Any,1} at index [3:4]

Additionally, there is a corner case that was introduced in Julia 0.5 with ==:

julia> @test ==(1, (1, 2)...)
Error During Test
  Test threw an exception of type BoundsError
  Expression: ==(1,(1,2)...)
  BoundsError: attempt to access 4-element Array{Any,1} at index [5]

julia> ==(1, (1, 2)...)
ERROR: MethodError: no method matching ==(::Int64, ::Int64, ::Int64)

The @test is failing here as we should see the MethodError and not the BoundsError.