Avoid excessive output from test errors (JuliaLang#28184)

* Don't print repr of exception when backtrace is also printed in test
error output.

Save decorated repr of exception instead of full undecorated repr

* Fix handling of limited output in logging

stdlib/Logging/src/ConsoleLogger.jl

@@ -111,10 +111,8 @@ function handle_message(logger::ConsoleLogger, level, message, _module, group, i
  valbuf = IOBuffer()
  rows_per_value = max(1, dsize[1]÷(length(kwargs)+1))
  valio = IOContext(IOContext(valbuf, logger.stream),
- :displaysize=>(rows_per_value,dsize[2]-5))
- if logger.show_limited
- valio = IOContext(valio, :limit=>true)
- end
+ :displaysize => (rows_per_value,dsize[2]-5),
+ :limit => logger.show_limited)
  for (key,val) in pairs(kwargs)
  showvalue(valio, val)
  vallines = split(String(take!(valbuf)), '\n')

stdlib/Test/src/Test.jl

@@ -141,7 +141,11 @@ mutable struct Error <: Result
  else
  bt_str = ""
  end
- new(test_type, orig_expr, repr(value), bt_str, source)
+ new(test_type,
+ orig_expr,
+ sprint(show, value, context = :limit => true),
+ bt_str,
+ source)
  end
 end
 function Base.show(io::IO, t::Error)
@@ -157,7 +161,7 @@ function Base.show(io::IO, t::Error)
  println(io, " Expression: ", t.orig_expr)
  print( io, " Value: ", t.value)
  elseif t.test_type == :test_error
- println(io, " Test threw exception ", t.value)
+ println(io, " Test threw exception")
  println(io, " Expression: ", t.orig_expr)
  # Capture error message and indent to match
  print(io, join(map(line->string(" ",line),
@@ -169,7 +173,7 @@ function Base.show(io::IO, t::Error)
  println(io, " Got correct result, please change to @test if no longer broken.")
  elseif t.test_type == :nontest_error
  # we had an error outside of a @test
- println(io, " Got exception $(t.value) outside of a @test")
+ println(io, " Got exception outside of a @test")
  # Capture error message and indent to match
  print(io, join(map(line->string(" ",line),
  split(t.backtrace, "\n")), "\n"))