test: add hard_link_count

Author: scivision

+stdlib/hard_link_count.m

@@ -3,10 +3,10 @@
 % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#getPosixFileAttributes(java.nio.file.Path,java.nio.file.LinkOption...)
 % https://docs.oracle.com/javase/tutorial/essential/io/links.html
 arguments
-  filepath (1,1) string {mustBeFile}
+  filepath (1,1) string
 end
 
-if ispc
+if ispc || ~isfile(filepath)
   c = [];
   return
 end

test/TestFileImpure.m

@@ -5,7 +5,7 @@
 end
 
 properties(TestParameter)
-in_exists = {pwd, string(mfilename("fullpath"))+".m", "not-exists"}
+in_exists = {pwd, mfilename("fullpath") + ".m", "not-exists"}
 ref_exists = {true, true, false}
 % on CI matlabroot can be writable!
 in_is_write = {pwd, "not-exists"};
@@ -357,6 +357,17 @@ function test_java_api(tc)
 tc.verifyGreaterThanOrEqual(v, 8)
 end
 
+function test_hard_link_count(tc)
+
+fn = mfilename("fullpath") + ".m";
+
+if ispc
+  tc.verifyEmpty(stdlib.hard_link_count(fn))
+end
+tc.verifyGreaterThanOrEqual(stdlib.hard_link_count(fn), 1)
+
+tc.verifyEmpty(stdlib.hard_link_count(tempname))
+
 end
 
 end