allow customizable RenderMode for txt

This commit enables a user to provide a `mode` keyword
to `@test_reference` for "txt" files, which overwrites
the default `RenderMode`.

This is useful if the text contains ANSII colors and
should not be displayed as a `Diff`, but rather as
a `BeforeAfter` (e.g. for testing UnicodePlots).

src/core.jl

@@ -89,7 +89,7 @@ function _test_reference(equiv, rendermode, file::File, actual::T) where T
             if isinteractive()
                 if input_bool("Replace reference with actual result (path: $path)?")
                     savefile(file, actual)
-                    warn("Please run the tests again for any changes to take effect")
+                    @warn("Please run the tests again for any changes to take effect")
                 else
                     @test false
                 end
@@ -108,7 +108,7 @@ function _test_reference(equiv, rendermode, file::File, actual::T) where T
                 if input_bool("Create reference file with above content (path: $path)?")
                     mkpath(dir)
                     savefile(file, actual)
-                    warn("Please run the tests again for any changes to take effect")
+                    @warn("Please run the tests again for any changes to take effect")
                 else
                     @test false
                 end

src/handlers.jl

@@ -1,13 +1,13 @@
 # --------------------------------------------------------------------
 # plain TXT
 
-function test_reference(file::File{format"TXT"}, actual)
-    _test_reference(Diff(), file, string(actual))
+function test_reference(file::File{format"TXT"}, actual; mode = Diff())
+    _test_reference(mode, file, string(actual))
 end
 
-function test_reference(file::File{format"TXT"}, actual::AbstractArray{<:AbstractString})
+function test_reference(file::File{format"TXT"}, actual::AbstractArray{<:AbstractString}; mode = Diff())
     str = join(actual, '\n')
-    _test_reference(Diff(), file, str)
+    _test_reference(mode, file, str)
 end
 
 # ---------------------------------
@@ -29,10 +29,10 @@ function test_reference(file::File, actual::AbstractArray{<:Colorant}; sigma=one
 end
 
 # Image as txt using ImageInTerminal
-function test_reference(file::File{format"TXT"}, actual::AbstractArray{<:Colorant}; size = (20,40))
+function test_reference(file::File{format"TXT"}, actual::AbstractArray{<:Colorant}; size = (20,40), mode = BeforeAfterFull())
     strs = @withcolor ImageInTerminal.encodeimg(ImageInTerminal.SmallBlocks(), ImageInTerminal.TermColor256(), actual, size...)[1]
     str = join(strs,'\n')
-    _test_reference(BeforeAfterFull(), file, str)
+    _test_reference(mode, file, str)
 end
 
 # --------------------------------------------------------------------

src/utils.jl

@@ -28,7 +28,7 @@ end
 io2str_impl(arg) = :(throw(ArgumentError("Invalid use of `@io2str` macro: The given argument `$($(string(arg)))` is not an expression.")))
 
 function io2str_impl(expr::Expr)
-    nvar = Symbol("#io#", randstring(4))
+    nvar = gensym("io")
     if replace_expr!(expr, :(::IO), nvar)
         esc(quote
             $nvar = Base.IOBuffer()

test/references/ansii.txt

@@ -0,0 +1 @@
+this should be blue

test/runtests.jl

@@ -77,6 +77,19 @@ end
     @test_reference "references/lena.txt" lena
 end
 
+@testset "plain ansi string" begin
+    @test_reference(
+        "references/ansii.txt",
+        @io2str(printstyled(IOContext(::IO, :color=>true), "this should be blue", color=:blue)),
+        mode = ReferenceTests.BeforeAfterFull()
+    )
+    @test_throws ErrorException @test_reference(
+        "references/ansii.txt",
+        @io2str(printstyled(IOContext(::IO, :color=>true), "this should be red", color=:red)),
+        mode = ReferenceTests.BeforeAfterFull()
+    )
+end
+
 @testset "string as SHA" begin
     @test_reference "references/number1.sha256" 1337
     foo = "foo"