fix(elk): scope rounded edge curve to ELK layout only by knsv-bot · Pull Request #7454 · mermaid-js/mermaid

knsv-bot · 2026-03-05T15:42:31Z

Summary

Scopes the fix from #7425 (issue #7213) so that the rounded curve is only applied when the ELK layout algorithm is used, rather than changing the global default for all flowcharts.

Reverts the global flowchart.curve default from 'rounded' back to 'basis'
Sets edge.curve = 'rounded' on each ELK edge right before insertEdge, ensuring ELK's orthogonal routes render with right-angle segments and rounded corners
Non-ELK layouts are completely unaffected

Resolves #7213

Test plan

Unit tests pass (973 flowchart + edge tests)
Config type verification passes
Build passes (no TS errors)
Visual verification — ELK edges route orthogonally with rounded corners
Cypress e2e snapshots
CI passes (lint, unit, e2e, type-check)

🤖 Generated with Claude Code

Reverts the global flowchart curve default from 'rounded' back to 'basis' and instead sets edge.curve = 'rounded' on each ELK edge right before insertEdge. This ensures ELK's orthogonal routes render with right-angle segments and rounded corners, without changing the default for non-ELK layouts. Fixes #7213 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

changeset-bot · 2026-03-05T15:42:37Z

⚠️ No Changeset found

Latest commit: 4c968e2

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codecov · 2026-03-05T15:46:51Z

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 3.53%. Comparing base (547e6d5) to head (4c968e2).
⚠️ Report is 448 commits behind head on master.

Files with missing lines	Patch %	Lines
packages/mermaid-layout-elk/src/render.ts	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #7454      +/-   ##
=========================================
- Coverage    3.59%   3.53%   -0.06%     
=========================================
  Files         475     493      +18     
  Lines       47191   49010    +1819     
  Branches      735     769      +34     
=========================================
+ Hits         1696    1734      +38     
- Misses      45495   47276    +1781

Flag	Coverage Δ
unit	`3.53% <0.00%> (-0.06%)`	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
packages/mermaid-layout-elk/src/render.ts	`0.12% <0.00%> (-0.01%)`	⬇️

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ashishjain0512

[sisyphus-bot]

Clean, focused fix — this is exactly the right scope for the ELK edge curve issue.

Note: PR targets master. This appears to be an intentional hotfix by the maintainer. Also note that PR #7452 covers this same fix bundled with other changes — worth clarifying which PR supersedes the other.

What's working well

🎉 [praise] Excellent scoping — the fix is isolated to just 3 files with no collateral changes. Reverting the global default to basis in config.schema.yaml:2160 and setting edge.curve = 'rounded' only in the ELK render path (render.ts:1073) is the cleanest possible approach.

🎉 [praise] Good explanatory comment on the edge.curve = 'rounded' line — "ELK produces orthogonal edge routes" explains the why, not just the what.

🎉 [praise] The changeset correctly scopes to both mermaid and @mermaid-js/mermaid-layout-elk packages with patch bumps. The description clearly communicates what changed and what's unaffected.

Things to address

🟡 [important] The PR checklist shows unchecked items for Cypress e2e snapshots and CI. Since this changes the rendering behavior of ELK edges, visual regression verification is important — especially to confirm that the original issue (#7213, curved ELK edges) is resolved and that non-ELK flowcharts are visually unchanged. It would be great to confirm CI passes cleanly before merge.

💡 [suggestion] Consider adding a Cypress e2e test case using the reproduction diagram from issue #7213 (the flowchart with subgraphs G1/G2 and repeated N11 --- N22 edges). This would prevent regression of this specific fix and serve as documentation that ELK edge routing is intentionally orthogonal.

Security

No XSS or injection issues. This PR only modifies a config default value and sets a string property (edge.curve) on an internal edge object. No user input handling, DOM manipulation, or sanitization changes.

Self-check

At least one 🎉 [praise] item exists (3)
No duplicate comments
Severity tally: 0 🔴 blocking / 1 🟡 important / 0 🟢 nit / 1 💡 suggestion / 3 🎉 praise
Verdict: COMMENT (1 🟡 — e2e verification pending)
Not a draft PR
No inline comments used
Tone check: constructive, appreciative

argos-ci · 2026-03-05T15:52:08Z

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Build	Status	Details	Updated (UTC)
default (Inspect)	👍 Changes approved	401 changed	Mar 5, 2026, 3:55 PM

knsv · 2026-03-05T16:50:26Z

The e2e test is there already

mermaid-bot · 2026-03-05T21:21:55Z

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* 'master' of https://github.com/mermaid-js/mermaid: fix(gantt): restore readable outside-text for done tasks in dark mode (#7456) fix(elk): scope rounded edge curve to ELK layout only (#7454)

* changeset-release/master: fix pnpm lock file Fix: ER diagram edge label positioning (#7453) chore: Update coupon fix(gantt): restore readable outside-text for done tasks in dark mode (#7456) fix(elk): scope rounded edge curve to ELK layout only (#7454) Version Packages fix: plausible build chore: Update plausible chore: Update release version in docs chore: Track editor picker selection fix: update broken docsy link and exclude bot-blocked domains from link checker chore: replace MERMAID_RELEASE_VERSION placeholders with current version fix: correct package name in changeset slow-lemons-know Updated Hero text Version Packages Fixed issue with hero text chore: Update banner with coupon Update link with source Updating the Hero on the docs side # Conflicts: # .changeset/rounded-edge-curves.md # .changeset/weak-tools-pay.md # cypress/integration/rendering/flowchart-v2.spec.js # packages/mermaid/CHANGELOG.md # packages/mermaid/src/rendering-util/createText.ts # packages/mermaid/src/rendering-util/rendering-elements/edges.js # packages/tiny/CHANGELOG.md # pnpm-lock.yaml

* master: (24 commits) Version Packages (#7561) Release candidate 11.14.0 (#7526) chore: Editor Picker V2 (#7497) Setting the link to Get started to the correct on Version Packages (#7466) fix: use correct package name for elk dummy commit Fix: ER diagram edge label positioning (#7453) chore: Update coupon fix(gantt): restore readable outside-text for done tasks in dark mode (#7456) fix(elk): scope rounded edge curve to ELK layout only (#7454) fix: plausible build chore: Update plausible chore: Update release version in docs chore: Track editor picker selection fix: update broken docsy link and exclude bot-blocked domains from link checker chore: replace MERMAID_RELEASE_VERSION placeholders with current version fix: correct package name in changeset slow-lemons-know Updated Hero text Version Packages ... # Conflicts: # .changeset/weak-tools-pay.md # docs/syntax/architecture.md # docs/syntax/timeline.md # docs/syntax/treeView.md # docs/syntax/wardley.md # docs/syntax/xyChart.md # packages/examples/CHANGELOG.md # packages/examples/package.json # packages/mermaid/CHANGELOG.md # packages/mermaid/package.json # packages/mermaid/src/diagrams/git/gitGraphRenderer.ts # packages/mermaid/src/docs/.vitepress/components/EditorSelectionModal.vue # packages/mermaid/src/docs/syntax/architecture.md # packages/mermaid/src/docs/syntax/timeline.md # packages/mermaid/src/docs/syntax/treeView.md # packages/mermaid/src/docs/syntax/wardley.md # packages/mermaid/src/docs/syntax/xyChart.md # packages/mermaid/src/rendering-util/rendering-elements/shapes/requirementBox.ts # packages/parser/CHANGELOG.md # packages/parser/package.json # packages/tiny/CHANGELOG.md # packages/tiny/package.json

github-actions Bot added the Type: Bug / Error Something isn't working or is incorrect label Mar 5, 2026

knsv marked this pull request as ready for review March 5, 2026 15:43

ashishjain0512 reviewed Mar 5, 2026

View reviewed changes

ashishjain0512 merged commit 0d5e35a into master Mar 5, 2026
17 of 18 checks passed

ashishjain0512 deleted the bug/7213_elk-edges-rounded-scoped-master branch March 5, 2026 21:21

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fix(elk): scope rounded edge curve to ELK layout only - #7454

fix(elk): scope rounded edge curve to ELK layout only#7454
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