is_readable improve test coverage

Author: scivision

+stdlib/+native/file_attributes.m

@@ -1,7 +1,4 @@
 function a = file_attributes(p)
-arguments
-  p {mustBeTextScalar}
-end
 
 assert(~stdlib.strempty(p), 'Path must not be empty.')
 

+stdlib/+native/is_readable.m

@@ -1,24 +1,15 @@
-function y = is_readable(p)
+function y = is_readable(file)
 
 y = false;
 
-if ~stdlib.exists(p), return, end
-
-if ~isMATLABReleaseOlderThan('R2025a')
-
-  props = "Readable";
-  if isunix
-    props = [props, "GroupRead", "OtherRead"];
-  end
-
-  t = getPermissions(filePermissions(p), props);
-  y = any(t{1, :});
-
-else
-
-  a = stdlib.native.file_attributes(p);
-  y = a.UserRead || a.GroupRead || a.OtherRead;
+if ~stdlib.exists(file), return, end
 
+props = "Readable";
+if isunix
+  props = [props, "GroupRead", "OtherRead"];
 end
 
+t = getPermissions(filePermissions(file), props);
+y = any(t{1, :});
+
 end

+stdlib/+native/is_readable_legacy.m

@@ -0,0 +1,10 @@
+function y = is_readable_legacy(file)
+
+if stdlib.exists(file)
+  a = stdlib.native.file_attributes(file);
+  y = a.UserRead || a.GroupRead || a.OtherRead;
+else
+  y = false;
+end
+
+end

+stdlib/is_readable.m

@@ -1,20 +1,18 @@
 %% IS_READABLE is file readable
 %
 %%% Inputs
-% p: string array of file paths
+% file: single path string
 %% Outputs
-% ok: logical array of the same size as p, true if file is readable
+% ok: true if file is readable
 
-function y = is_readable(p)
-arguments
-  p {mustBeTextScalar}
-end
+function y = is_readable(file)
 
 if stdlib.has_java()
-  y = stdlib.java.is_readable(p);
+  y = stdlib.java.is_readable(file);
+elseif isMATLABReleaseOlderThan('R2025a')
+  y = stdlib.native.is_readable_legacy(file);
 else
-  y = stdlib.native.is_readable(p);
+  y = stdlib.native.is_readable(file);
 end
 
-
 end

test/TestExists.m

@@ -8,7 +8,7 @@
 {tempname(), false}
 }
 % on CI matlabroot can be writable!
-isr_fun = {@stdlib.is_readable, @stdlib.java.is_readable, @stdlib.native.is_readable}
+isr_fun = {@stdlib.is_readable, @stdlib.java.is_readable, @stdlib.native.is_readable, @stdlib.native.is_readable_legacy}
 isw_fun = {@stdlib.is_writable, @stdlib.java.is_writable, @stdlib.native.is_writable}
 end