Hide code lines with `#hide` when executing Markdown, fixes #166 (#188)

CHANGELOG.md

@@ -6,6 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- Lines with trailing `#hide` are not shown in output of Markdown execution with Documenter
+  flavour. ([#188][github-188])
 
 ## [2.12.1] - 2022-02-10
 ### Fixed

src/Literate.jl

@@ -529,19 +529,19 @@ function markdown(inputfile, outputdir=pwd(); config::AbstractDict=Dict(), kwarg
                 write(iocode, "; continued = true")
             end
             write(iocode, '\n')
+            # filter out trailing #hide unless code is executed by Documenter
+            execute = config["execute"]::Bool
+            write_hide = isdocumenter(config) && !execute
+            write_line(line) = write_hide || !endswith(line, "#hide")
             for line in chunk.lines
-                # filter out trailing #hide (unless leaving it for Documenter)
-                if !(endswith(line, "#hide") && !isdocumenter(config))
-                    write(iocode, line, '\n')
+                write_line(line) && write(iocode, line, '\n')
             end
-            end
-            if isdocumenter(config) && REPL.ends_with_semicolon(chunk.lines[end])
+            if write_hide && REPL.ends_with_semicolon(chunk.lines[end])
                 write(iocode, "nothing #hide\n")
             end
             write(iocode, codefence.second, '\n')
-            write_code = !(all(l -> endswith(l, "#hide"), chunk.lines) && !isdocumenter(config))
-            write_code && write(iomd, seekstart(iocode))
-            if config["execute"]::Bool
+            any(write_line, chunk.lines) && write(iomd, seekstart(iocode))
+            if execute
                 execute_markdown!(iomd, sb, join(chunk.lines, '\n'), outputdir;
                                   inputfile=config["literate_inputfile"],
                                   flavor=config["flavor"],

test/runtests.jl

@@ -817,6 +817,11 @@ end end
                 #-
                 print("hello there")
                 nothing
+                #-
+                a = 2 + 2
+                print("a: ", a); nothing #hide
+                #-
+                47 #hide
                 """)
             Literate.markdown(inputfile, outdir; execute=true)
             markdown = read(joinpath(outdir, "inputfile.md"), String)
@@ -830,9 +835,16 @@ end end
             @test occursin("```\nPlain\n```", markdown) # text/plain, fredrikekre/Literate#187
             @test occursin("```\nhello, world\n```", markdown) # stdout/stderr
             @test occursin("```\n42\n```", markdown) # result over stdout/stderr
+            @test occursin("```julia\n123+123;\n```", markdown) # no additional `nothing #hide`, fredrikekre/Literate.jl/issues/166#issuecomment-979987878
             @test !occursin("246", markdown) # empty output because trailing ;
             @test !occursin("```\nnothing\n```", markdown) # empty output because nothing as return value
             @test occursin("```\nhello there\n```", markdown) # nothing as return value, non-empty stdout
+            @test occursin("```julia\na = 2 + 2\n```", markdown) # line with `#hide` removed
+            @test occursin("```\na: 4\n```", markdown) # nothing as return value, non-empty stdout
+            @test !occursin("```julia\n47 #hide\n```", markdown) # line with `#hide` removed
+            @test !occursin("```julia\n```", markdown) # no empty code block
+            @test occursin("```\n47\n```", markdown) # return value (even though line/block removed)
+
             # FranklinFlavor
             Literate.markdown(inputfile, outdir; execute=true, flavor=Literate.FranklinFlavor())
             markdown = read(joinpath(outdir, "inputfile.md"), String)