The MATLAB "Java-bridge" test program fails because of the wrong data type

[mwinkel-dev]

Affiliation
MIT PSFC

Version(s) Affected
client: alpha-7-153-5 (but likely applies to all recent MDSplus versions)
server: n/a
MATLAB: R2023b

Platform(s)
Ubuntu 24 (but likely applies to all platforms)

Installation Method(s)
Using the mdsplus.org package repository

Describe the bug
When using MATLAB with MDSplus, an early task is to make sure that the API's bridges are working. This is done by running the mdstest.m script in MATLAB. The Java bridge is tested with mdstest(0); the Python bridge with mdstest(1). Unfortunately, the Java bridge test expects a char but instead receives a string, so throws an error.

To Reproduce
Steps to reproduce the behavior:

1. After installing MATLAB set its search path to include /usr/local/mdsplus/matlab.
2. At the MATLAB >> prompt, type mdstest(0)
3. MATLAB then generates the following error.

>> mdstest(0)
Error "string test": expected class char got string

ans =

  logical

   0

>> 

Expected behavior
The mdstest(0) should pass; no errors should be generated.

Screenshots
n/a

Additional context
Presumably, there were changes in recent versions of MATLAB that changed the returned datatype. If so, the fix likely involves a minor change to the $MDSPLUS_DIR/matlab/mdstest.m script.

This issue was observed when working on Issue #2925.

[santorofer]

I also see the same issue when running the code with:
mdstest()
mdstest(1)

[mwinkel-dev]

This is likely a duplicate of Issue #2987. The pending PR #2990 should fix the issue.