Prevent invalid modificationTypes from loading monomers

[Copilot]

How the feature works? / How did you fix the issue?

Invalid modificationTypes values (empty/formatting/overlong) previously allowed monomers to load into the library, contradicting the expected validation behavior. This change blocks those invalid definitions and logs a clear error, keeping the library clean.

• Monomer library validation
  • Rejects invalid modificationTypes during updateMonomersLibrary and logs a targeted error message before the monomer is inserted.
• Unit coverage
  • Adds tests for empty/formatting invalid values and a valid path to ensure acceptance remains correct.

Example validation guard:

const invalidReason = getInvalidModificationTypesReason(
  newMonomer.props?.modificationTypes,
);
if (invalidReason) {
  KetcherLogger.error(
    `Load of "${newMonomer.props.MonomerName}" monomer has failed, ` +
      `monomer definition contains invalid modificationTypes value. ${invalidReason}`,
  );
  return;
}

Screenshot: https://github.com/user-attachments/assets/7c84219d-20b0-46de-9f76-f75aea20bebe

Check list

• unit-tests written
• e2e-tests written
• documentation updated
• PR name follows the pattern #1234 – issue name
• branch name doesn't contain '#'
• PR is linked with the issue
• base branch (master or release/xx) is correct
• task status changed to "Code review"
• reviewers are notified about the pull request

Original prompt

---

This section details on the original issue you should resolve

<issue_title>System should not load monomer to the library if modificationTypes value contain inproper symbols</issue_title>
<issue_description>Steps to Reproduce

1. Open Macromolecules - Flex mode (clean canvas)
2. Go to console and execute following commands:

_Peptide1 with tab in modificationTypes value

await ketcher.updateMonomersLibrary('\n  -INDIGO-10122515372D\n\n  0  0  0  0  0  0  0  0  0  0  0 V3000\nM  V30 BEGIN CTAB\nM  V30 COUNTS 1 0 0 0 0\nM  V30 BEGIN ATOM\nM  V30 1 _Peptide1 11.975 -7.85 0.0 0 CLASS=AA SEQID=1\nM  V30 END ATOM\nM  V30 BEGIN BOND\nM  V30 END BOND\nM  V30 END CTAB\nM  V30 BEGIN TEMPLATE\nM  V30 TEMPLATE 1 AA/_Peptide1/_Peptide1/ NATREPLACE=AA/A\nM  V30 BEGIN CTAB\nM  V30 COUNTS 4 3 3 0 0\nM  V30 BEGIN ATOM\nM  V30 1 C -0.75 0.0 0.0 0\nM  V30 2 C 0.25 0.0 0.0 0\nM  V30 3 H 0.75 0.866 0.0 0\nM  V30 4 H 0.75 -0.866 0.0 0\nM  V30 END ATOM\nM  V30 BEGIN BOND\nM  V30 1 2 1 2\nM  V30 2 1 2 3\nM  V30 3 1 2 4\nM  V30 END BOND\nM  V30 BEGIN SGROUP\nM  V30 1 SUP 1 ATOMS=(1 3) XBONDS=(1 2) BRKXYZ=(9 -0.250000 -0.433000 0.00000-\nM  V30 0 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000) LABEL=H CLASS-\nM  V30 =LGRP\nM  V30 2 SUP 2 ATOMS=(1 4) XBONDS=(1 3) BRKXYZ=(9 -0.250000 0.433000 0.000000-\nM  V30  0.000000 0.000000 0.000000 0.000000 0.000000 0.000000) LABEL=H CLASS=-\nM  V30 LGRP\nM  V30 3 SUP 3 ATOMS=(2 1 2) XBONDS=(2 2 3) BRKXYZ=(9 0.250000 0.433000 0.000-\nM  V30 000 0.250000 -0.433000 0.000000 0.000000 0.000000 0.000000) LABEL=_Pep-\nM  V30 tide1 CLASS=AA SAP=(3 2 3 Al) SAP=(3 2 4 Br) NATREPLACE=AA/A\nM  V30 END SGROUP\nM  V30 END CTAB\nM  V30 END TEMPLATE\nM  END\n>  <type>\nmonomerTemplate\n\n>  <modificationTypes>\n \t ;\n\n$$$$\n', { format: 'sdf' })

Actual behavior
_Peptide1 amino acid appears in the library

Expected behavior
Monomer doesn't appear at the Library
System throws an error in console: Load of "_Peptide1" monomer has failed, monomer definition contains invalid modificationTypes value. The modificationTypes couldn't be empty

As per requirement:

• modificationTypes - string, optional. Used for aminoacids modification through the context menu.
  Format: Any symbol except formatting ones, max length 200, spaces allowed
  If value doesn't fit format - throw an error

Environment details:

• Ketcher Version 3.9.0-rc.1 Build at 2025-10-02; 16:35:40
• Indigo Version 1.37.0-rc.1.0-gca09660df-wasm32-wasm-clang-19.0.0
• Chrome Version 141.0.7390.55 (Official Build) (64-bit)
• Win10

Related issue: epam/Indigo#3161</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes System should not load monomer to the library if modificationTypes value contain inproper symbols #8357

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