file creation tests: check path existence before & after (#29994)

Author: StefanKarpinski

test/file.jl

@@ -1015,15 +1015,28 @@ rm(dir)
 mktempdir() do dir
     name1 = joinpath(dir, "apples")
     name2 = joinpath(dir, "bannanas")
-    @test touch(name1) == name1 # when it doesn't exist
-    @test touch(name1) == name1 # when it does exist
+    @test !ispath(name1)
+    @test touch(name1) == name1
+    @test isfile(name1)
+    @test touch(name1) == name1
+    @test isfile(name1)
+    @test !ispath(name2)
     @test mv(name1, name2) == name2
+    @test !ispath(name1)
+    @test isfile(name2)
     @test cp(name2, name1) == name1
+    @test isfile(name1)
+    @test isfile(name2)
     namedir = joinpath(dir, "chalk")
     namepath = joinpath(dir, "chalk","cheese","fresh")
-    @test mkdir(namedir) == namedir # when it doesn't exist
-    @test mkpath(namepath) == namepath # when it doesn't exist
-    @test mkpath(namepath) == namepath # when it does exist
+    @test !ispath(namedir)
+    @test mkdir(namedir) == namedir
+    @test isdir(namedir)
+    @test !ispath(namepath)
+    @test mkpath(namepath) == namepath
+    @test isdir(namepath)
+    @test mkpath(namepath) == namepath
+    @test isdir(namepath)
 end