Preview: A new nucleotide should not be added to the end of a cyclic sequence, if the last nucleotide of the sequence does not have a free AP R1 or R2

[ViktoriaTkacheva]

Steps to Reproduce

1. Switch to the Macro mode

2. Draw a cyclic sequence, consisting of any 4 nucleotides, for example:

   

3. Switch to the Sequence mode - the Text-editing mode

   

4. Add any nucleotide to the end of this sequence

5. Switch to the Flex mode and move all nucleotides apart from each other so that all bonds are visible

Actual behavior
A new nucleotide is added to the end of a cyclic sequence. The bond, that provided and displayed cyclicity, disappears in the Sequence mode and the Flex mode

Expected behavior
A new nucleotide should not be added to the end of a cyclic sequence, if the last nucleotide of the sequence does not have a free AP R1 or R2. An error message appears on the canvas (From BA):

Error Message:
It is impossible to merge fragments. Attachment point to establish bonds are not available.

Screenshots

2024-05-28_19h34_16.mp4

Desktop (please complete the following information):

• OS: Windows 10 Pro (version 22H2) x64
• Browser: Сhrome
• Version: (125.0.6422.61) x64

Ketcher version 2.21.0-rc.2, Build at 2024-05-28; 14:29:04

related with

• Cyclic chains disappear from canvas when try to Edit in the sequence mode #4548

[NadezhdaPeskun]

Should be verified with next Issues: (#4708, #4575, #4506, #4706) + #4328
Error Message should appear:
Error Message:
It is impossible to merge fragments. Attachment point to establish bonds are not available.

[AlexeyGirin]

Verified.

• Indigo Toolkit Version 1.21.0-rc.1.0-g9194599b2-wasm32-wasm-clang-19.0.0
• Ketcher Version 2.22.0-rc.2 Build at 2024-06-03; 18:43:00
• Chrome Version 125.0.6422.142 (Official Build) (64-bit)
• Windows 10

[Zhirnoff]

Automated.