fileio.samepath: correct validation, add test

Author: scivision

+stdlib/+fileio/private/mustBeScalarOrEmpty.m

@@ -0,0 +1,7 @@
+function mustBeScalarOrEmpty(x)
+
+if ~(isempty(x) || isscalar(x))
+  throwAsCaller(MException('MATLAB:validators:mustBeScalarOrEmpty', "must be scalar or empty"))
+end
+
+end

+stdlib/+fileio/samepath.m

@@ -1,9 +1,14 @@
 function issame = samepath(path1, path2)
 %% samepath(path1, path)
 % true if inputs resolve to same path
+% files need not exist
+%%% Inputs
+% * path1, path2: paths to compare
+%%% Outputs
+% issame: logical
 arguments
-  path1 (1,1) string {mustBeNonzeroLengthText}
-  path2 (1,1) string {mustBeNonzeroLengthText}
+  path1 string {mustBeScalarOrEmpty}
+  path2 string {mustBeScalarOrEmpty}
 end
 
 import stdlib.fileio.absolute_path

+stdlib/+test/TestFilePure.m

@@ -12,6 +12,16 @@ function test_posix(tc)
   tc.verifyFalse(contains(posix("c:\foo"), "\"))
   tc.verifyFalse(all(contains(posix(["x:\123", "d:\abc"]), "\")))
 end
+end
+
+function test_samepath(tc)
+import stdlib.fileio.samepath
+
+tc.verifyEmpty(samepath(string.empty, string.empty))
+tc.verifyTrue(samepath("", ""))
+tc.verifyFalse(samepath("a", "b"))
+tc.verifyTrue(samepath("a/b/..", "a/c/.."))
+tc.verifyTrue(samepath(".", "a/.."))
 
 end