clean up coverage files generated by test (#522)

* clean up coverage files generated by test
* delete coverage files more nicely

test/code_coverage/code_coverage.jl

@@ -1,32 +1,59 @@
-# delete any present coverage files
-let
+function cleanup_coverage_files(pid)
+    # clean up coverage files for source code
+    dir, _, files = first(walkdir(normpath(@__DIR__, "..", "..", "src")))
+    for file in files
+        reg = Regex(string(".+\\.jl\\.$pid\\.cov"))
+        if occursin(reg, file)
+            rm(joinpath(dir, file))
+        end
+    end
+
+    # clean up coverage files for this file
     dir, _, files = first(walkdir(@__DIR__))
     for file in files
-        if occursin(r"coverage_example\.jl\.\d+\.cov", file)
+        reg = Regex(string("coverage_example\\.jl\\.$pid\\.cov"))
+        if occursin(reg, file)
             rm(joinpath(dir, file))
         end
     end
 end
 
-#using DiffUtils
+# using DiffUtils
 
-@testset "code coverage" begin
-    out = read(`$(Base.julia_cmd()) --startup=no --project=$(dirname(dirname(@__DIR__))) --code-coverage=user
-                $(joinpath(@__DIR__(), "coverage_example.jl"))`, String)
-    @test out == "1 2 fizz 4 "
-
-    dir, _, files = first(walkdir(@__DIR__))
-    i = findfirst(contains(r"coverage_example\.jl\.\d+\.cov"), files)
-    i === nothing && error("no coverage files found in $dir: $files")
-    cov_file = joinpath(dir, files[i])
-    cov_data = read(cov_file, String)
-    expected = read(joinpath(dir, "coverage_example.jl.cov"), String)
-    if Sys.iswindows()
-        cov_data = replace(cov_data, "\r\n" => "\n")
-        expected = replace(cov_data, "\r\n" => "\n")
+let
+    local pid
+    try
+        @testset "code coverage" begin
+            io = IOBuffer()
+            filepath = normpath(@__DIR__, "coverage_example.jl")
+            cmd = `$(Base.julia_cmd()) --startup=no --project=$(dirname(dirname(@__DIR__)))
+                --code-coverage=user $filepath`
+            p = run(pipeline(cmd; stdout=io); wait=false)
+            pid = Libc.getpid(p)
+            wait(p)
+            out = String(take!(io))
+            @test out == "1 2 fizz 4 "
+
+            dir, _, files = first(walkdir(@__DIR__))
+            i = findfirst(contains(r"coverage_example\.jl\.\d+\.cov"), files)
+            i === nothing && error("no coverage files found in $dir: $files")
+            cov_file = joinpath(dir, files[i])
+            cov_data = read(cov_file, String)
+            expected = read(joinpath(dir, "coverage_example.jl.cov"), String)
+            if Sys.iswindows()
+                cov_data = replace(cov_data, "\r\n" => "\n")
+                expected = replace(cov_data, "\r\n" => "\n")
+            end
+
+            # if cov_data != expected
+            #     DiffUtils.diff(cov_data, expected)
+            # end
+            @test cov_data == expected
+        end
+    finally
+        if @isdefined(pid)
+            # clean up generated files
+            cleanup_coverage_files(pid)
+        end
     end
-    #if cov_data != expected
-    #    DiffUtils.diff(cov_data, expected)
-    #end
-    @test cov_data == expected
 end