Improve shape validation of DataPipe objects (#724)

* Update validateShape.m

* Make comments wrt enforceScalarSize flag clearer

Author: ehennestad

+types/+util/checkDims.m

@@ -5,11 +5,21 @@ function checkDims(valueSize, validSizes, enforceScalarSize)
 % of valid sizes, validates that the value size matches at least one of them.
 %
 % types.util.CHECKDIMS(valsize, validSizes, enforceScalarSize) optionally
-% enforces stricter validation for vectors. By default, MATLAB vectors 
-% (column: [n,1], row: [1,n]) pass validation against a 1D size (Inf), 
-% because vector data is typically treated as 1D when written to file. 
-% However, DataPipe may write vector data as 2D. To prevent 2D sizes from 
-% being accepted as 1D, use the enforceScalarSize flag.
+% enforces stricter validation for scalar/1D shapes. By default, MATLAB 
+% vectors with shape [n,1] (column) or [1,n] (row) will pass validation 
+% against a 1D size specification of [Inf], because vector data is typically 
+% treated as 1D when written to file. However, in some cases (e.g., DataPipe 
+% maxSize), the 2D shape [n,1] or [1,n] determines the actual shape in the 
+% exported file. Set enforceScalarSize to true to reject 2D vector shapes 
+% when a 1D shape like [Inf] is specified for validSize.
+%
+% Example:
+%   % Without strict enforcement, [5,1] matches [Inf]:
+%   types.util.checkDims([5,1], {Inf}, false);  % OK
+%   
+%   % With strict enforcement, [5,1] does NOT match [Inf]:
+%   types.util.checkDims([5,1], {Inf}, true);   % Error
+%   types.util.checkDims(5, {Inf}, true);       % OK
 
 if nargin < 3 % Set default value for enforceScalarSize if not provided
     enforceScalarSize = false;

+types/+util/validateShape.m

@@ -16,11 +16,13 @@ function validateShape(propertyName, validShapes, value)
         end
     elseif isa(value, 'types.untyped.DataPipe')
         valueShape = value.internal.maxSize;
-        % For data pipes, vectors can be exported to HDF5 files as 2D arrays
-        % (columnar (n,1) or row (1,n)). The types.util.checkDims function allows
-        % this, even if the valid shape specifies that the data should be 1D.
-        % Use 'enforceScalarShape' to ensure that 2D-like vectors do not
-        % pass validation when the valid shape specifies 1D data.
+        % For DataPipe objects, vectors can be exported to HDF5 files as 2D arrays
+        % with shape [n,1] (column) or [1,n] (row). By default, types.util.checkDims 
+        % allows these 2D shapes to pass validation even when the valid shape 
+        % specifies 1D data (e.g., [Inf]). However, for DataPipe, the maxSize 
+        % property determines the actual shape in the exported file, so we need 
+        % stricter validation. Set 'enforceScalarShape' to true to ensure that 
+        % shapes like [n,1] or [1,n] are not accepted when [Inf] is specified.
         enforceScalarShape = true;
     elseif istable(value)
         valueShape = [height(value) 1];
@@ -49,7 +51,17 @@ function validateShape(propertyName, validShapes, value)
     % Check actual size of DataPipe and warn if it is not valid
     if isa(value, 'types.untyped.DataPipe')
         try
+            if enforceScalarShape
+                % Reset enforceScalarShape to false when validating the current 
+                % data size. Strict validation is only needed for maxSize, which 
+                % determines the final shape of the dataset in the exported file. 
+                % The current data size is allowed to be more flexible (e.g., 
+                % [n,1] can match [Inf]).
+                enforceScalarShape = false;
+            end
+
             valueShape = size(value);
+
             types.util.checkDims(valueShape, validShapes, enforceScalarShape);
         catch ME
             warning(...