Merge pull request #19 from jakewilliami/real-path-expansion

Refine real path expansion logic
jakewilliami · Sep 27, 2022 · c06777b · c06777b · jakewilliami · Sep 27, 2022
2 parents 32ae046 + 9d31a1b
commit c06777b
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diff --git a/Project.toml b/Project.toml
@@ -1,7 +1,7 @@
 name = "HiddenFiles"
 uuid = "d01c2003-3cc0-4d61-912c-b250feb01c5b"
 authors = ["Jake Ireland <[email protected]> and contributors"]
-version = "0.1.0"
+version = "0.1.1"
 
 [compat]
 julia = "1"

diff --git a/src/HiddenFiles.jl b/src/HiddenFiles.jl
@@ -14,10 +14,13 @@ Check if a file or directory is hidden.
 On Unix-like systems, a file or directory is hidden if it starts with a full stop/period (`U+002e`).  On Windows systems, this function will parse file attributes to determine if the given file or directory is hidden.
 
 !!! note
-    On macOS and BSD, this function will also check the `st_flags` field from `stat` to check if the `UF_HIDDEN` flag has been set.
+    On Unix-like systems, in order to correctly determine if the file begins with a full stop, we must first expand the path to its real path.
 
 !!! note
-    On macOS, any file or directory within a [package](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFBundles/DocumentPackages/DocumentPackages.html) or a [bundle](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFBundles/AboutBundles/AboutBundles.html) will be considered hidden.
+    On operating systems deriving from BSD (i.e., *BSD, macOS), this function will also check the `st_flags` field from `stat` to check if the `UF_HIDDEN` flag has been set.
+
+!!! note
+    On macOS, any file or directory within a [package](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFBundles/DocumentPackages/DocumentPackages.html) or a [bundle](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFBundles/AboutBundles/AboutBundles.html) will also be considered hidden.
 """
 ishidden
 
@@ -27,13 +30,14 @@ include("docs.jl")
     include("utils/zfs.jl")
     if iszfs()  # @static breaks here # ZFS
         error("not yet implemented")
-        _ishidden_zfs(f::AbstractString) = error("not yet implemented")
+        _ishidden_zfs(f::AbstractString, rp::AbstractString) = error("not yet implemented")
+        _ishidden = _ishidden_zfs
     end
 
     # Trivial Unix check
     _isdotfile(f::AbstractString) = startswith(basename(f), '.')
-    # Account for ZFS
-    _ishidden_unix(f::AbstractString) = _isdotfile(f) || (iszfs() && _ishidden_zfs())
+    # Check dotfiles, but also account for ZFS
+    _ishidden_unix(f::AbstractString, rp::AbstractString) = _isdotfile(rp) || (iszfs() && _ishidden_zfs("", ""))
 
     @static if Sys.isbsd()  # BDS-related; this is true for macOS as well
         # https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/chflags.2.html
@@ -60,7 +64,7 @@ include("docs.jl")
         # https://github.com/davidkaya/corefx/blob/4fd3d39f831f3e14f311b0cdc0a33d662e684a9c/src/System.IO.FileSystem/src/System/IO/FileStatus.Unix.cs#L88
         _isinvisible(f::AbstractString) = (_st_flags(f) & UF_HIDDEN) == UF_HIDDEN    
 
-        _ishidden_bsd_related(f::AbstractString) = _ishidden_unix(f) || _isinvisible(f)
+        _ishidden_bsd_related(f::AbstractString, rp::AbstractString) = _ishidden_unix(f, rp) || _isinvisible(rp)
     end
 
     @static if Sys.isapple()  # macOS/Darwin
@@ -137,9 +141,13 @@ include("docs.jl")
         # If a file or directory exists inside a package or bundle, then it is hidden.  Packages or bundles themselves
         # are not necessarily hidden.
         function _exists_inside_package_or_bundle(f::AbstractString)
-            # This assumes that f has already been modified with the realpath function, as if it hasn't,
+            # This function necessitates that f has is modified with the realpath function, as if it hasn't,
             # it is possible that f has a trailing slash, meaning its dirname is still itself
             f = dirname(f)
+
+            # We can't check the root directory, as this doesn't have any metadata information, so
+            # _k_mditem_content_type_tree will fail.  Otherwise, we start at the parent directory of the
+            # given file, and check if any of its parents are packages or bundles.
             while f != "/"
                 _ispackage_or_bundle(f) && return true
                 f = dirname(f)
@@ -149,10 +157,10 @@ include("docs.jl")
 
 
         #=== All macOS cases ===#
-        _ishidden_macos(f::AbstractString) = _ishidden_bsd_related(f) || _issystemfile(f) || _exists_inside_package_or_bundle(f)
+        _ishidden_macos(f::AbstractString, rp::AbstractString) = _ishidden_bsd_related(f, rp) || _issystemfile(f) || _exists_inside_package_or_bundle(rp)
         _ishidden = _ishidden_macos
     elseif Sys.isbsd()  # BSD; this excludes macOS through control flow (as macOS is checked for first)
-        _ishidden_bsd(f::AbstractString) = _ishidden_bsd_related(f)
+        _ishidden_bsd(f::AbstractString, rp::AbstractString) = _ishidden_bsd_related(f, rp)
         _ishidden = _ishidden_bsd
     else  # General UNIX
         _ishidden = _ishidden_unix
@@ -164,10 +172,10 @@ elseif Sys.iswindows()
     const FILE_ATTRIBUTE_HIDDEN = 0x2
     const FILE_ATTRIBUTE_SYSTEM = 0x4
 
-    function _ishidden_windows(f::AbstractString)
+    function _ishidden_windows(f::AbstractString, rp::AbstractString)
         # https://docs.microsoft.com/en-gb/windows/win32/api/fileapi/nf-fileapi-getfileattributesa
         # DWORD GetFileAttributesA([in] LPCSTR lpFileName);
-        f_attrs = ccall(:GetFileAttributesA, UInt32, (Cstring,), f)
+        f_attrs = ccall(:GetFileAttributesA, UInt32, (Cstring,), rp)
 
         # https://stackoverflow.com/a/1343643/12069968
         # https://stackoverflow.com/a/14063074/12069968
@@ -182,8 +190,26 @@ end
 # Each OS branch defines its own _ishidden function.  In the main ishidden function, we check that the path exists, expand
 # the real path out, and apply the branch's _ishidden function to that path to get a final result
 function ishidden(f::AbstractString)
-    ispath(f) || throw(Base.uv_error("ishidden($(repr(f)))", Base.UV_ENOENT))
-    return _ishidden(realpath(f))
+    # If path does not exist, `realpath` will error™
+    local rp::String
+    try
+        rp = realpath(f)
+    catch e
+        err_prexif = "ishidden($(repr(f)))"
+        # Julia < 1.3 throws a SystemError when `realpath` fails
+        isa(e, SystemError) && throw(SystemError(err_prexif, e.errnum))
+        # Julia ≥ 1.3 throws an IOError, constructed from UV Error codes
+        isa(e, Base.IOError) && throw(Base.uv_error(err_prexif, e.code))
+        # If this fails for some other reason, rethrow
+        rethrow()
+    end
+
+    # Julia < 1.2 on Windows does not error on `realpath` if path does not exist, so we
+    # must do so manually here
+    ispath(rp) || throw(Base.uv_error("ishidden($(repr(f)))", Base.UV_ENOENT))
+
+    # If we got here, the path exists, and we can continue safely with our _ishidden checks
+    return _ishidden(f, rp)
 end
 
 

diff --git a/src/docs.jl b/src/docs.jl
@@ -1,10 +1,12 @@
 """
 ```julia
-_ishidden(f::AbstractString) -> Bool
+_ishidden(f::AbstractString, rp::AbstractString) -> Bool
 ```
 
 An alias for your system's internal `_ishidden_*` function.
 
+This function also takes an expanded real path, as some internal functions neccesitate a real path.
+
 The reason this is still an internal function is because the main [`ishidden`](@ref) function also checks the validity of the path, so that all internal functions can assume that the path exists.
 
 See also: [`_ishidden_unix`](@ref), [`_ishidden_windows`](@ref), [`_ishidden_macos`](@ref), [`_ishidden_bsd`](@ref), [`_ishidden_zfs`](@ref).
@@ -27,17 +29,23 @@ _isdotfile(f::AbstractString) -> Bool
 ```
 
 Determines if a file or directory is hidden from ordinary directory listings by checking if it starts with a full stop/period (`U+002E`).
+
+!!! note
+    This function expects the path given to be a normalised/real path, so that the base name of the path can be correctly assessed.
 """
 _isdotfile
 
 """
 ```julia
-_ishidden_unix(f::AbstractString) -> Bool
+_ishidden_unix(f::AbstractString, rp::AbstractString) -> Bool
 ```
 
 Determines if a file or directory is hidden from ordinary directory listings by checking if it starts with a full stop/period, or if it is a ZFS mount point on operating systems with a Unix-like interface.
 
 See also: [`_isdotfile`](@ref), [`_ishidden_zfs`](@ref).
+
+!!! note
+    This function expects the path given to be a normalised/real path, so that the base name of the path can be correctly assessed.
 """
 _ishidden_unix
 
@@ -88,12 +96,15 @@ _isinvisible(f::AbstractString) -> Bool
 Determines if the specified file or directory is invisible/hidden, as defined by the Finder flags for the path.
 
 See also: [`_st_flags`](@ref), [`UF_HIDDEN`](@ref).
+
+!!! note
+    This function expects that the file given to it is its real path.
 """
 _isinvisible
 
 """
 ```julia
-_ishidden_bsd_related(f::AbstractString) -> Bool
+_ishidden_bsd_related(f::AbstractString, rp::AbstractString) -> Bool
 ```
 
 Determines if a file or directory on a BSD-related system (i.e., macOS or BSD) is hidden from ordinary directory listings, as defined either by the Unix standard, or by user-defined flags.
@@ -154,12 +165,15 @@ _exists_inside_package_or_bundle(f::AbstractString) -> Bool
 Determines whether the given path exists inside a package or bundle on macOS.  If it does, the path will be considered hidden.
 
 See also: [`_ispackage_or_bundle`](@ref), [`_ishidden_macos`](@ref)
+
+!!! note
+    This function necessitates/expects that the file given to it is its real path, as it is possible that the file provided has a trailing slash, meaning the first "parent" this function will check is itself.  This also makes relative paths much simpler to work with.
 """
 _exists_inside_package_or_bundle
 
 """
 ```julia
-_ishidden_macos(f::AbstractString) -> Bool
+_ishidden_macos(f::AbstractString, rp::AbstractString) -> Bool
 ```
 
 Determines if the specified file or directory on macOS is hidden from ordinary directory listings.  There are a few conditions this function needs to check:
@@ -182,7 +196,7 @@ _ishidden_macos
 
 """
 ```julia
-_ishidden_bsd(f::AbstractString) -> Bool
+_ishidden_bsd(f::AbstractString, rp::AbstractString) -> Bool
 ```
 
 Determines if the specified file or directory is hidden from ordinary directory listings by checking the following conditions:
@@ -219,10 +233,13 @@ FILE_ATTRIBUTE_SYSTEM
 
 """
 ```julia
-_ishidden_windows(f::AbstractString) -> Bool
+_ishidden_windows(f::AbstractString, rp::AbstractString) -> Bool
 ```
 
 Determine if the specified file or directory is hidden from ordinary directory listings for operating systems that are derivations of Microsoft Windows NT.
+
+!!! note
+    This function necessitates/expects that the file given to it is its real path.
 """
 _ishidden_windows
 
diff --git a/test/runtests.jl b/test/runtests.jl
@@ -1,6 +1,9 @@
 using HiddenFiles
 using Test
+
 @testset "HiddenFiles.jl" begin
+    randpath(path_len::Integer = 64) = String(rand(Char, path_len))  # this path shouldn't exist
+
     @static if Sys.isunix()
         function mk_temp_dot_file(parent::String = tempdir())
             tmp_hidden = joinpath(parent, '.' * basename(tempname()))
@@ -13,7 +16,7 @@ using Test
         @testset "HiddenFiles.jl—General UNIX" begin
             @test ishidden(p)
             @test !ishidden(homedir())
-            @test_throws Base.IOError HiddenFiles.ishidden("~/$(basename(p′))")
+            @test_throws Union{Base.IOError, SystemError} HiddenFiles.ishidden("~/$(basename(p′))")
             @test HiddenFiles.ishidden(expanduser("~/$(basename(p′))"))
         end
 
@@ -38,11 +41,15 @@ using Test
                 # Case 4: Packages and bundles
                 @test !ishidden("/System/Applications/Utilities/Terminal.app")
                 @test ishidden("/System/Applications/Utilities/Terminal.app/Contents")
+                @test ishidden("/System/Applications/Utilities/Terminal.app/Contents/../../Terminal.app/Contents")
+                @test ishidden("/////System/Applications/Utilities/Terminal.app/Contents/../Contents")
+                @test ishidden("/System/Applications/Utilities/Terminal.app/Contents/../Contents///MacOS////../MacOS/../../Contents/MacOS/Terminal///")
+                @test !ishidden("/")
                 @test ishidden("/System/Applications/Utilities/Terminal.app/Contents/")  # This should be the same as above, as we expand all paths using realpath
                 @test !HiddenFiles._ispackage_or_bundle("/System/Applications/Utilities/Terminal.app/Contents/")
                 @test HiddenFiles._exists_inside_package_or_bundle("/System/Applications/Utilities/Terminal.app/Contents/")
                 @test !HiddenFiles._exists_inside_package_or_bundle("/bin/")
-                f = String(rand(Char, 32))  # this path shouldn't exist
+                f = randpath()
                 cfstr_nonexistent = HiddenFiles._cfstring_create_with_cstring(f)
                 @test_throws Exception HiddenFiles._mditem_create(cfstr_nonexistent)
                 encoding_mode_nonexistent = 0x1c000101  # this encoding mode should not exist
@@ -96,4 +103,11 @@ using Test
             @test false
         end
     end
+
+
+    @testset "HiddenFiles.jl—Path Handling" begin
+        f = randpath()
+        # Julia < 1.3 throws a SystemError when `realpath` fails
+        @test_throws Union{Base.IOError, SystemError} ishidden(f)
+    end
 end