add some windows handling

Author: mortenpi

src/MultiDocumenter.jl

@@ -74,13 +74,9 @@ function walk_outputs(f, root, docs::Vector{MultiDocRef}, dirs::Vector{String})
         p = joinpath(root, ref.path)
         for dir in dirs
             dirpath = joinpath(p, dir)
-            # Symlinks do not really work on Windows. There are permissions problems and we can not
-            # actually traverse them.
-            if Sys.iswindows() && islink(dirpath)
-                @warn "[WINDOWS] Symlink encountered at $(dirpath) -- excluding from search index, since symlinks are not properly supported on Windows."
+            if !_windows_symlink_wrapper(isdir, dirpath)
                 continue
             end
-            isdir(dirpath) || continue
             DocumenterTools.walkdocs(dirpath, DocumenterTools.isdochtml) do fileinfo
                 f(relpath(dirname(fileinfo.fullpath), root), fileinfo.fullpath)
             end
@@ -487,4 +483,27 @@ function inject_styles_and_global_navigation(
     end
 end
 
+function _windows_symlink_wrapper(f::Base.Callable, path::AbstractString)
+    if Sys.iswindows() && islink(path)
+        if isinteractive()
+            @warn """
+            A symlink was ignored for $(f) at $(path)
+            This only happens when running interactive on Windows."""
+            return false
+        else
+            throw(SymlinkOnWindowsError())
+        end
+    end
+    return f(path)
+end
+
+struct SymlinkOnWindowsError <: Exception end
+function Base.showerror(io::IO, err::SymlinkOnWindowsError)
+    print(io, """
+    SymlinkOnWindowsError: this builds requires symlinks, but these are not properly supported in Windows
+     You can still run the build interactively for debugging/testing (i.e. in the REPL), but the
+     build will not exactly match the full build.""")
+    print(io, err.msg)
+end
+
 end

test/runtests.jl

@@ -107,8 +107,16 @@ MultiDocumenter.make(
     @testset "structure" begin
         @test isdir(outpath, "inf")
         @test !isdir(outpath, "inf", "previews")
-        @test isdir(outpath, "inf", "stable")
-        @test isfile(outpath, "inf", "stable", "index.html")
+        if Sys.iswindows()
+            # On Windows, symlinks are either kept as simple files, or are in fact
+            # symlinks, but then you would run into permission errors with isdir().
+            # So we need to have platform-specific test logic here.
+            path = joinpath(outpath, "inf", "stable")
+            @test islink(path) || isdir(path)
+        else
+            @test isdir(outpath, "inf", "stable")
+            @test isfile(outpath, "inf", "stable", "index.html")
+        end
 
         @test read(joinpath(outpath, "inf", "index.html"), String) == """
         <!--This file is automatically generated by Documenter.jl-->