some maintenance

Project.toml

@@ -17,3 +17,9 @@ Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
 Reexport = "^1"
 Suppressor = "^0.2.0"
 julia = "^1"
+
+[extras]
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[targets]
+test = ["Test"]

src/DisplayTricks.jl

@@ -4,13 +4,12 @@
 
 export as_mime
 
-struct AsMIME
-    mime::MIME
+struct AsMIME{M <: MIME}
+    mime::M
     x::Any
 end
 
-Base.showable(m::MIME, am::AsMIME) = m == am.mime
-Base.show(io::IO, m::MIME, am::AsMIME) = Base.show(io, m, am.x)
+Base.show(io::IO, m::M, am::AsMIME{M}) where M <: MIME = Base.show(io, m, am.x)
 
 function as_mime(m::MIME)
     x -> as_mime(m, x)
@@ -76,13 +75,12 @@ repr(MIME"text/latex"(), s) == "\\\\frac{hello}{world}"
 ```
 
 """
-struct Show
-    mime::MIME
+struct Show{M <: MIME}
+    mime::M
     data
 end
 
-Base.showable(m::MIME, x::Show) = x.mime == m
-Base.show(io::IO, ::MIME, x::Show) = write(io, x.data)
+Base.show(io::IO, ::M, x::Show{M}) where M <: MIME = write(io, x.data)
 
 
 """
@@ -116,18 +114,20 @@ large_df = DataFrame(rand(100,100))
 WithIOContext(large_df, :displaysize => (9999,9999))
 ```
 """
-struct WithIOContext
-    x
-    context_properties
-    WithIOContext(x, props::Pair...; moreprops...) = new(x, [props..., moreprops...])
+struct WithIOContext{T}
+    x::T
+    context::IOContext{Base.DevNull}
+    WithIOContext(x::T, props::Pair...; moreprops...) where T = new{T}(x, IOContext(devnull, props..., moreprops...))
 end
 
+Base.:(==)(w1::WithIOContext, w2::WithIOContext) = w1.x == w2.x && w1.context == w2.context
+
 function Base.show(io::IO, m::MIME, w::WithIOContext)
-	Base.show(IOContext(io, w.context_properties...), m, w.x)
+	Base.show(IOContext(io, w.context), m, w.x)
 end
 # we need to add a more specific method for text/plain because Julia base has a fallback method here
 function Base.show(io::IO, m::MIME"text/plain", w::WithIOContext)
-	Base.show(IOContext(io, w.context_properties...), m, w.x)
+	Base.show(IOContext(io, w.context), m, w.x)
 end
 
 Base.showable(m::MIME, w::WithIOContext) = Base.showable(m, w.x)

test/runtests.jl

@@ -0,0 +1,68 @@
+using PlutoUI
+using Test
+
+
+@testset "DisplayTricks" begin
+
+    x = "asdf"
+
+    # Show
+
+    @test repr(MIME"derp1"(), Show(MIME"derp1"(), x)) == codeunits(x)
+
+    Base.istextmime(::MIME"derp2") = true
+
+    @test repr(MIME"derp2"(), Show(MIME"derp2"(), codeunits(x))) == x
+
+
+    s = Show(MIME"cool1"(), x)
+
+
+    @test Base.showable(MIME"text/plain"(), x)
+    @test !Base.showable(MIME"cool1"(), x)
+    # everything is plaintext showable
+    @test Base.showable(MIME"text/plain"(), s)
+    @test Base.showable(MIME"cool1"(), s)
+
+
+    # AsMIME
+
+    mimer = as_mime(MIME"cool2"())
+    am = mimer(s)
+
+    @test Base.showable(MIME"cool1"(), s)
+    @test !Base.showable(MIME"cool2"(), s)
+    @test Base.showable(MIME"text/plain"(), s)
+
+    @test !Base.showable(MIME"cool1"(), am)
+    @test Base.showable(MIME"cool2"(), am)
+    @test Base.showable(MIME"text/plain"(), am)
+
+
+    # WithIOContext
+
+    @test WithIOContext(s, :a => 1, :b => 2) ==
+        WithIOContext(s, :a => 1; b = 2) ==
+        WithIOContext(s, a = 1; b = 2) ==
+        WithIOContext(s; a = 1, b = 2)
+
+
+    @test repr(MIME"text/plain"(), WithIOContext(1.345234523452, compact=true)) == "1.34523"
+    @test repr(MIME"text/plain"(), WithIOContext(1.345234523452, compact=false)) == "1.345234523452"
+
+
+    struct Uhm end
+    m = MIME"hello"()
+    Base.istextmime(::MIME"hello") = true
+
+    Base.show(io::IO, ::MIME"hello", ::Uhm) = print(io, get(io, :prop, missing))
+
+    u = Uhm()
+
+    @test repr(m, WithIOContext(u, prop=1)) == "1"
+end
+
+
+
+
+