Add File.same?(path1, path2) with follow_symlinks option (#6161)

crystal-lang · Jun 4, 2018 · 4e48495 · 4e48495
1 parent 94bd7bf
commit 4e48495
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Showing 4 changed files with 30 additions and 5 deletions.
diff --git a/spec/std/file_spec.cr b/spec/std/file_spec.cr
@@ -230,21 +230,40 @@ describe "File" do
         File.link(in_path, out_path)
         File.exists?(out_path).should be_true
         File.symlink?(out_path).should be_false
-        File.info(in_path).should eq(File.info(out_path))
+        File.same?(in_path, out_path).should be_true
       ensure
         File.delete(out_path) if File.exists?(out_path)
       end
     end
   end
 
+  describe "same?" do
+    it "compares following symlinks only if requested" do
+      file = "#{__DIR__}/data/test_file.txt"
+      symlink = "#{__DIR__}/data/test_file_symlink.txt"
+      other = "#{__DIR__}/data/test_file.ini"
+
+      begin
+        File.symlink(file, symlink)
+
+        File.same?(file, symlink).should be_false
+        File.same?(file, symlink, follow_symlinks: true).should be_true
+        File.same?(file, symlink, follow_symlinks: false).should be_false
+        File.same?(file, other).should be_false
+      ensure
+        File.delete(symlink) if File.exists?(symlink)
+      end
+    end
+  end
+
   describe "symlink" do
     it "creates a symbolic link" do
       in_path = "#{__DIR__}/data/test_file.txt"
       out_path = "#{__DIR__}/data/test_file_symlink.txt"
       begin
         File.symlink(in_path, out_path)
         File.symlink?(out_path).should be_true
-        File.info(in_path).should eq(File.info(out_path))
+        File.same?(in_path, out_path, follow_symlinks: true).should be_true
       ensure
         File.delete(out_path) if File.exists?(out_path)
       end

diff --git a/src/crystal/system/unix/file_info.cr b/src/crystal/system/unix/file_info.cr
@@ -54,7 +54,7 @@ struct Crystal::System::FileInfo < ::File::Info
     @stat.st_gid.to_u32
   end
 
-  def ==(other : ::File::Info) : Bool
+  def same_file?(other : ::File::Info) : Bool
     @stat.st_dev == other.@stat.st_dev && @stat.st_ino == other.@stat.st_ino
   end
 end
diff --git a/src/file.cr b/src/file.cr
@@ -82,6 +82,12 @@ class File < IO::FileDescriptor
     Crystal::System::File.exists?(path)
   end
 
+  # Returns `true` if *path1* and *path2* represents the same file.
+  # The comparison take symlinks in consideration if *follow_symlinks* is `true`.
+  def self.same?(path1 : String, path2 : String, follow_symlinks = false) : Bool
+    info(path1, follow_symlinks).same_file? info(path2, follow_symlinks)
+  end
+
   # Returns the size of *filename* bytes. Raises `Errno` if the file at *path*
   # does not exist.
   #

diff --git a/src/file/info.cr b/src/file/info.cr
@@ -99,11 +99,11 @@ class File
     # The group ID that the file belongs to.
     abstract def group : UInt32
 
-    # Two `File::Info`s are equal if and only if they are of the same file.
+    # Returns true if this `Info` and *other* are of the same file.
     #
     # On unix, this compares device and inode fields, and will compare equal for
     # hard linked files.
-    abstract def ==(other : File::Info)
+    abstract def same_file?(other : File::Info) : Bool
 
     # Returns true if this `Info` represents a standard file. Shortcut for
     # `type.file?`.