This is not official test data from the HELM project, but may give you some other examples for your work with HELM.
HELM examples from PDB
File from Roger.
"File containing 1000 (inline) HELM strings from ChEMBL 21.These HELM (unlike those from the EBI) use the Pistoia Alliance's monomer definitions, so any of these can be pasted into the online Pistoia HELM editor. The use of inline SMILES (in about a quarter of the examples) should push ChemDraw's parser a bit more than many of the examples on the internet. There are also examples of multiple peptide chains, and nucleic acid sequences, but alas this still doesn't cover all of the corners of the HELM v2 (or v1.1) specification."
Note: the file extension is not a HELM approved convention.