<NME> runtests.jl
<BEF> using Test
import Documenter
include("TestUtilities.jl"); using Main.TestUtilities

@testset "Documenter" begin
    # Build the example docs
    @info "Building example/make.jl"
    include("examples/make.jl")

    # Test missing docs
    @info "Building missingdocs/make.jl"
    include("missingdocs/make.jl")

    # Error reporting.
    @info "Building errors/make.jl"
    @quietly include("errors/make.jl")

    # Unit tests for module internals.
    include("except.jl")
    include("utilities.jl")
    include("remotes.jl")

    # DocChecks tests
    include("docchecks.jl")

    # NavNode tests.
    include("navnode.jl")

    # DocSystem unit tests.
    include("docsystem.jl")

    # CrossReferences
    include("crossreferences.jl")

    # DocTest unit tests.
    @info "Running tests in doctests/"
    include("doctests/docmeta.jl")
    include("doctests/doctestapi.jl")
    include("doctests/doctests.jl")
    include("doctests/fix/tests.jl")

    # DOM Tests.
    include("dom.jl")

    # MDFlatten tests.
    include("mdflatten.jl")

    # Main build pipeline (Builder and Expanders modules)
    include("pipeline.jl")

    # HTMLWriter
    include("htmlwriter.jl")

    # LaTeXWriter

    # A simple build evaluating code outside build directory
    include("workdir/tests.jl")
end

# Additional tests
    # A simple build outside of a Git repository
    @info "Building nongit/tests.jl"
    @quietly include("nongit/tests.jl")

    # A simple build evaluating code outside build directory
    @info "Building workdir/tests.jl"
    @quietly include("workdir/tests.jl")

    # Passing a writer positionally (https://github.com/JuliaDocs/Documenter.jl/issues/1046)
    @test_throws ArgumentError makedocs(sitename="", HTML())

    # Running doctest() on our own manual
    @info "doctest() Documenter's manual"
    @quietly include("manual.jl")
end

<MSG> Do not declare writers <: Plugin

Currently the HTML, Markdown and LaTeX objects can be passed as
positional arguments to makedocs, but they do not have any effect,
effectively failing silently. With this, they can only be passed via the
format keyword.

The Writer abstract type is currently not part of the public API.

<DFF> @@ -55,6 +55,9 @@ println("="^50)
 
     # A simple build evaluating code outside build directory
     include("workdir/tests.jl")
+
+    # Passing a writer positionally (https://github.com/JuliaDocs/Documenter.jl/issues/1046)
+    @test_throws ArgumentError makedocs(sitename="", HTML())
 end
 
 # Additional tests

Do not declare writers <: Plugin