rewrite show as writemime for Julia v0.4

README.md

@@ -75,6 +75,10 @@ Currently, the `@compat` macro supports the following syntaxes:
 
 * `@compat withenv(f, "a" => a, "b" => b...)` on 0.3.
 
+* `@compat import Base.show => Base.writemime` because writemime is deprecated in Julia 0.5 ([#16563]).
+
+* `@compat function show(args...) => writemime` because writemime is deprecated in Julia 0.5 ([#16563]).
+
 ## Type Aliases
 
 * `String` has undergone multiple changes: in Julia 0.3 it was an abstract type and then got renamed to `AbstractString` in 0.4; in 0.5, `ASCIIString` and `ByteString` were deprecated, and `UTF8String` was renamed to the (now concrete) type `String`.

src/Compat.jl

@@ -187,6 +187,14 @@ if VERSION < v"0.5.0-dev+961"
     end
 end
 
+function rewrite_show(ex)
+    argtypes = ex.args[2:end]
+    if length(argtypes) == 2
+        insert!(argtypes, 2, Expr(:(::), :macrocall, MIME"text/plain"))
+    end
+    return Expr(:call, :writemime, argtypes...)
+end
+
 function rewrite_dict(ex)
     length(ex.args) == 1 && return ex
 
@@ -438,6 +446,8 @@ function _compat(ex::Expr)
             rewrite_pairs_to_tuples!(ex)
         elseif VERSION < v"0.4.0-dev+1246" && f == :String
             ex = Expr(:call, :bytestring, ex.args[2:end]...)
+        elseif VERSION < v"0.5.0-dev+4340" && length(ex.args) > 2 && ex.args[1] === :show
+            ex = rewrite_show(ex)
         end
         if VERSION < v"0.5.0-dev+4305"
             rewrite_iocontext!(ex)
@@ -516,6 +526,10 @@ function _compat(ex::Expr)
             # f.(arg) -> broadcast(f, arg)
             return Expr(:call, :broadcast, _compat(ex.args[1]), _compat(ex.args[2]))
         end
+    elseif ex.head === :import
+        if VERSION < v"0.5.0-dev+4340" && length(ex.args) == 2 && ex.args[1] === :Base && ex.args[2] === :show
+            ex.args[2] = :writemime
+        end
     end
     return Expr(ex.head, map(_compat, ex.args)...)
 end

test/runtests.jl

@@ -1,10 +1,31 @@
 using Compat
 import Compat.String
+@compat import Base.show
 using Base.Test
 
 v = 1
 @test_throws AssertionError @assert(v < 1)
 
+type TestCustomShowType end
+@compat function show(io::IO, ::MIME"text/plain", ::TestCustomShowType)
+    print(io, "MyTestCustomShowType")
+end
+myio = IOBuffer()
+display(TextDisplay(myio), MIME"text/plain"(), TestCustomShowType())
+@test @compat String(myio) == "MyTestCustomShowType"
+
+type TestCustomShowType2 end
+@compat show(io::IO, ::MIME"text/plain", ::TestCustomShowType2) = print(io, "MyTestCustomShowType2")
+myio = IOBuffer()
+display(TextDisplay(myio), MIME"text/plain"(), TestCustomShowType2())
+@test @compat String(myio) == "MyTestCustomShowType2"
+
+type TestCustomShowType3 end
+@compat show(io::IO, ::TestCustomShowType3) = print(io, "2-Argument-show")
+myio = IOBuffer()
+display(TextDisplay(myio), TestCustomShowType3())
+@test @compat String(myio) == "2-Argument-show"
+
 d = Dict{Int,Int}()
 d[1] = 1
 @test Compat.@Dict(1 => 1) == d