fix(er): recognize '1' cardinality alias before relationship operators

[kaigritun]

Summary

Fixes #7351

The 1 alias for only one cardinality was not being recognized when directly followed by relationship operators like -- or ...

Example that failed before this fix:

erDiagram
   CUSTOMER 1--one or more DELIVERY-ADDRESS : has

Root cause

The lexer rule for the 1 alias only matched when 1 was followed by whitespace and then a letter:

"1"(?=\s+[A-Za-z_"'])           return 'ONLY_ONE';

This meant 1 to worked (space + letter) but 1-- didn't (no space, operator directly follows).

Fix

Added a new lexer rule to also recognize 1 when directly followed by the relationship operators (--, .., .-, -.):

"1"(?=(\-\-|\.\.|\.\-|\-\.))    return 'ONLY_ONE';

Tests

Added two test cases covering:

• 1-- (identifying relationship)
• 1.. (non-identifying relationship)

Checklist

• Bug fix
• Tests added
• Lint passes

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🦋 Changeset detected

Latest commit: d347f77

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Additional details and impacted files

@@            Coverage Diff             @@
##           develop   #7375      +/-   ##
==========================================
- Coverage     3.58%   3.58%   -0.01%     
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  Files          474     475       +1     
  Lines        47529   47540      +11     
  Branches       740     740              
==========================================
  Hits          1706    1706              
- Misses       45823   45834      +11     

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Build	Status	Details	Updated (UTC)
default (Inspect)	👍 Changes approved	2 added	Feb 12, 2026, 6:12 AM

[omkarht]

Suggestion: Consider adding visual rendering tests in cypress/integration/rendering/erDiagram.spec.js to verify the fix renders correctly. This would help catch any visual regressions.

Also, since the regex covers all 4 relationship operators (--, .., .-, -.), it would be good to add unit tests for 1.- and 1-. as well for completeness.

[kaigritun]

Addressed the review feedback:

1. Added unit tests for 1.- and 1-. relationship operators in erDiagram.spec.js - now tests all 4 operator styles (--, .., .-, -.)
2. Added visual rendering test that covers all 4 relationship operator styles with the 1 cardinality alias
3. Added changeset file (nine-bugs-drop.md)

Thanks for the thorough review!

[omkarht]

Thanks for this contribution, nice to see the tests covering all operators too. I see that a changeset has been included, From my side this looks good, thanks again for the fix.
Please refer #7375 (review)

[omkarht]

Kindly resolve the failing test case

[kaigritun]

Fixed the failing test - the expectation was incorrect. Per the jison grammar, -. (solid-to-dotted) returns NON_IDENTIFYING, not IDENTIFYING. Updated both the comment and the assertion.

[omkarht]

Thanks for the clarification and for aligning the test with the jison grammar.
The update looks good to me now, all tests are passing

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[DavidSeptimus]

I'm confused about this change. I can't reproduce the error described in the original issue in v11.12.2 or v11.12.3, but I am noticing that in v11.13.0, 1 followed by a space and then then the relationship operator causes a parsing error when it was previously working.

erDiagram
   %% doesn't work in v11.13.0
   CUSTOMER 1 --one or more DELIVERY-ADDRESS : has

   %% works in v11.13.0
   CUSTOMER 1--one or more DELIVERY-ADDRESS : has