# this file contains some utilities copied from the Documenter.jl package
# (https://github.com/JuliaDocs/Documenter.jl), see LICENSE.md for license
module Documenter

function withoutput(f)
    # Save the default output streams.
    default_stdout = stdout
    default_stderr = stderr

    # Redirect both the `stdout` and `stderr` streams to a single `Pipe` object.
    pipe = Pipe()
    Base.link_pipe!(pipe; reader_supports_async = true, writer_supports_async = true)
    redirect_stdout(pipe.in)
    redirect_stderr(pipe.in)
    # Also redirect logging stream to the same pipe
    logger = Base.CoreLogging.SimpleLogger(pipe.in)

    # Bytes written to the `pipe` are captured in `output` and converted to a `String`.
    output = UInt8[]

    # Run the function `f`, capturing all output that it might have generated.
    # Success signals whether the function `f` did or did not throw an exception.
    result, success, backtrace = Base.CoreLogging.with_logger(logger) do
        try
            f(), true, Vector{Ptr{Cvoid}}()
        catch err
            err, false, catch_backtrace()
        finally
            # Force at least a single write to `pipe`, otherwise `readavailable` blocks.
            println()
            # Restore the original output streams.
            redirect_stdout(default_stdout)
            redirect_stderr(default_stderr)
            # NOTE: `close` must always be called *after* `readavailable`.
            append!(output, readavailable(pipe))
            close(pipe)
        end
    end
    return result, success, backtrace, chomp(String(output))
end

end