Weekly GitHub Report for Mermaid

Thank you for subscribing to our weekly newsletter! Each week, we deliver a comprehensive summary of your GitHub project's latest activity right to your inbox, including an overview of your project's issues, pull requests, contributors, and commit activity.

Table of Contents

• I. News
  • 1.1. Recent Version Releases
  • 1.2. Other Noteworthy Updates
• II. Issues
  • 2.1. Top 5 Active Issues
  • 2.2. Top 5 Stale Issues
  • 2.3. Open Issues
  • 2.4. Closed Issues
  • 2.5. Issue Discussion Insights

• III. Pull Requests
  • 3.1. Open Pull Requests
  • 3.2. Closed Pull Requests
  • 3.3. Pull Request Discussion Insights

• IV. Contributors
  • 4.1. Contributors

I. News

1.1 Recent Version Releases:

The current version of this repository is @mermaid-js/[email protected]

1.2 Version Information:

On March 25, 2025, a minor update was released that introduced the addition of a Radar Chart, enhancing the charting capabilities of the platform. This update reflects ongoing efforts to expand visualization options.

II. Issues

2.1 Top 5 Active Issues:

We consider active issues to be issues that that have been commented on most frequently within the last week. Bot comments are omitted.

1. [STATUS: TRIAGE] C4 diagrams: unified renderer migration and c4-beta - PR series tracker: This issue tracks the comprehensive migration of the C4 diagrams in Mermaid from the legacy row-grid renderer to a unified rendering pipeline, alongside introducing a new structurizr-inspired c4-beta syntax. It organizes the work into two parallel tracks—one for in-place migration of existing syntax to the unified renderer and another for the new c4-beta syntax gated on an RFC—and provides detailed status updates, PR dependencies, open questions, and community issue triage related to this migration effort.

   • The comment section extensively documents progress updates, detailed technical reviews, CI status, merge readiness, and ongoing discussions about review dismissals and baseline approvals; it also highlights the need for maintainer decisions on open questions and the status of the c4-beta RFC track, while noting that all review threads have been addressed and the series is awaiting maintainer actions to proceed.
   • Number of comments this week: 3

2. [TYPE: BUG / ERROR] [STATUS: TRIAGE] Mermaid bundles 0.9.3 version of ELK: This issue addresses the problem that Mermaid currently bundles version 0.9.3 of ELK, which is licensed under EUPL and incompatible with Forgejo, preventing Forgejo from upgrading to newer Mermaid versions due to dependency and licensing conflicts. The user requests an upgrade to ELK 0.12.X, which has a more permissive license, to unblock Forgejo's ability to update Mermaid.

   • The comments clarify that ELK has been bundled since Mermaid 12.0 with the updated license starting at ELK 0.12.0, and a small standalone pull request is ready to bump ELK to this version; the user expresses preference for a separate PR to expedite the update process.
   • Number of comments this week: 2

3. [TYPE: BUG / ERROR] [STATUS: TRIAGE] quadrantChart: a point coordinate written as 1.0 gives a lexical error: This issue reports a lexical error occurring when parsing quadrant chart points with coordinates written as 1.0 or 1.00, which are valid according to the documentation but cause the parser to fail, while coordinates written as 1 or 0.0 parse correctly. The problem stems from lexer rules that only allow fractional parts for zero but not for one, and a proposed fix involves updating these rules to accept 1 with optional decimal zeros, with a fix and tests already prepared and submitted as a pull request.

   • The comments confirm the issue is reproducible and explain the root cause in the lexer rules; a fix has been implemented and is available in a referenced pull request.
   • Number of comments this week: 2

4. [TYPE: ENHANCEMENT] [CONTRIBUTOR NEEDED] [STATUS: APPROVED] [GOOD FIRST ISSUE!] Flowchart on hover tooltip: This issue requests the addition of hover tooltips to flowchart nodes in Mermaid diagrams, allowing users to display extra information without cluttering the diagram itself. The feature aims to generalize the tooltip functionality seen in User Journey diagrams by showing a tooltip when hovering over any flowchart node, potentially indicated by a marker and changing the cursor to a pointer, with a simple syntax inspired by sequence diagram notes.

   • The comments show interest from multiple users wanting to work on the feature, with one proposing a solution that reuses existing node metadata syntax to implement static hover tooltips without extra JavaScript, and plans to add tests and documentation; questions about naming and scope were also raised.
   • Number of comments this week: 1

5. [TYPE: ENHANCEMENT] [TYPE: NEW DIAGRAM] BPMN support: This issue requests adding support for BPMN (Business Process Model and Notation) diagrams to Mermaid, motivated by the desire to create and maintain business process definitions within tools like Notion that already support Mermaid. The discussion centers around scoping the feature to focus initially on Level 1 BPMN elements for documentation and communication purposes, with multiple community members sharing prototypes, use cases, and suggestions for syntax and integration approaches.

   • The comments reveal strong community interest in a Level 1 BPMN implementation as a practical MVP, with several independent prototype efforts and plugins shared; maintainers and contributors discuss parser choices, syntax design, integration with existing tools like Obsidian, and the trade-offs between core Mermaid support versus external plugins, while also addressing export/import capabilities and future roadmap considerations.
   • Number of comments this week: 1

2.2 Top 5 Stale Issues:

We consider stale issues to be issues that has had no activity within the last 30 days. The team should work together to get these issues resolved and closed as soon as possible.

As of our latest update, there are no stale issues for the project this week.

2.3 Open Issues

This section lists, groups, and then summarizes issues that were created within the last week in the repository.

Issues Opened This Week: 28

Summarized Issues:

• Parsing and Lexer Issues in Charts: Multiple issues describe parsing bugs and lexer errors in Mermaid's quadrantChart, xychart, Sankey, radar, and Venn diagram components. These include incorrect token consumption, improper keyword matching, invalid coordinate formats, and whitespace handling that cause silent data loss, incorrect rendering, or parse failures.
• issues/8512, issues/8525, issues/8526, issues/8527, issues/8529, issues/8535, issues/8537, issues/8539, issues/8541, issues/8542, issues/8543

• Text Styling and Markdown Parsing Problems: Issues report problems with nested bold and italic text losing outer styles when htmlLabels is false, markdown strings in xychart not parsing backticks correctly, and unquoted multi-word text losing spaces during rendering. These cause incorrect visual output and formatting inconsistencies in diagrams.
• issues/8500, issues/8530, issues/8531

• Diagram Rendering and Layout Bugs: Several issues highlight rendering bugs such as incorrect orientation in xychart due to case sensitivity, overflow causing invalid SVG paths in radar charts, and edge placement errors in swimlane-beta layouts. These bugs lead to diagrams being drawn incorrectly or with invalid SVG elements.
• issues/8528, issues/8546, issues/8568

• Error Message and Entity Decoding Problems: Multiple issues describe error messages displaying internal entity placeholders instead of decoded characters for axis labels, set identifiers, and pie chart values. This causes confusing output that does not match the rendered diagrams and complicates debugging.
• issues/8540, issues/8544, issues/8545

• Feature Requests for Diagram Enhancements: Requests include adding hypergraph visualization support, Chen notation for ER diagrams, and configurable KaTeX rendering options to improve Mermaid's diagram capabilities and customization. These proposals aim to extend Mermaid's functionality for specialized use cases.
• issues/8505, issues/8508, issues/8533

• Library and Dependency Updates: One issue requests upgrading the bundled ELK library to resolve licensing incompatibilities affecting downstream projects, ensuring compliance and enabling upgrades. Another involves updating to a new version of @zenuml/core with fixes and improvements scoped carefully to avoid unrelated changes.
• issues/8507, issues/8510

• Diagram Content and Visualization Requests: A detailed flow diagram for a crude distillation unit process is requested, describing multiple separation and treatment steps in an oil refinery. This reflects user needs for domain-specific diagram templates and examples.
• issues/8523

• Sankey Diagram Data Validation Issues: Problems include acceptance of non-numeric values rendering as NaN links and parse failures caused by improper whitespace trimming due to missing multiline regex flags. These issues cause invisible paths and incorrect node labels in Sankey diagrams.
• issues/8535, issues/8536

• HTML Escaping and Accessibility Bugs: Titles and accessibility descriptions containing < characters are incorrectly double-escaped, resulting in visible HTML entities like < instead of the intended characters. This affects multiple diagram types and their accessibility features.
• issues/8558

2.4 Closed Issues

This section lists, groups, and then summarizes issues that were closed within the last week in the repository. This section also links the associated pull requests if applicable.

Issues Closed This Week: 4

Summarized Issues:

• Diagram Rendering and Notation Issues: Several issues focus on improving the visual representation and notation accuracy in Mermaid diagrams. One issue proposes animating link styles with new syntax and CSS keyframe animations, while another addresses the need for UML guillemets («include» and «extend») in use case diagrams to conform with UML standards without changing source syntax.
• [issues/5574, issues/8392]

• Dependency Updates and Feature Integration: There is a concern about updating the repository to incorporate the new @zenuml/core version 4.7.0, which introduces a split on-canvas participant editor and various fixes. The update must be carefully scoped, tested, and integrated without enabling the new editor by default to maintain stability.
• [issues/8440]

• Connector Style Regression: An update to version 12.2.0 caused a regression where all rounded connectors in flowcharts were replaced by angular connectors, disrupting layout and color schemes. This change negatively affected the appearance and arrangement of most charts, indicating a significant rendering issue.
• [issues/8496]

2.5 Issue Discussion Insights

This section will analyze the tone and sentiment of discussions within this project's open and closed issues that occurred within the past week. It aims to identify potentially heated exchanges and to maintain a constructive project environment.

Based on our analysis, there are no instances of toxic discussions in the project's open or closed issues from the past week.

III. Pull Requests

3.1 Open Pull Requests

This section provides a summary of pull requests that were opened in the repository over the past week. The top three pull requests with the highest number of commits are highlighted as 'key' pull requests. Other pull requests are grouped based on similar characteristics for easier analysis. Up to 25 pull requests are displayed in this section, while any remaining pull requests beyond this limit are omitted for brevity.

Pull Requests Opened This Week: 38

Key Open Pull Requests

1. feat(flowchart): add tooltip key to node metadata: This pull request adds a tooltip key to flowchart node metadata in Mermaid, enabling nodes to display hover tooltips without requiring a click event or JavaScript callback, while ensuring tooltip text is properly sanitized, supporting numeric values, maintaining existing click-tooltip behavior, and including comprehensive tests and documentation.

• URL: pull/8511

• Associated Commits: 3c822, f966b, 4a225

2. fix(kanban): reject unsupported style statements: This pull request fixes the Kanban parser to reject unsupported style <id> <css> statements with an explicit parser error instead of treating them as node declarations, adds regression tests covering various indentation and case scenarios including CSS custom properties, removes unsupported style statements from sample diagrams, and documents the changes while ensuring existing valid uses of the word "style" remain unaffected.

• URL: pull/8538

• Associated Commits: 6e73b, 44d54, 6a31f

3. fix: decode entity placeholders in pie, radar and venn error messages: This pull request introduces a decodeEntityPlaceholders helper function to properly decode internal entity placeholders in error messages for pie, radar, and venn diagrams, ensuring that these messages display human-readable text instead of raw placeholders without altering validation logic or error formats.

• URL: pull/8549

• Associated Commits: a188e, 3e50c, 39d5f

Other Open Pull Requests

• Rendering fixes and improvements: Multiple pull requests address rendering issues across various diagram types and browsers. These include fixing flaky Gantt diagram tests by stabilizing timestamps and timezone settings, resolving Safari-specific sequence diagram label and note box rendering bugs, correcting radar chart NaN coordinate issues, and improving sequence diagram self-call rendering with proper activation boundaries.
• [pull/8566, pull/8509, pull/8522, pull/8517]

• Diagram parsing and lexer enhancements: Several pull requests improve parsing robustness and lexer behavior for Mermaid diagrams. Fixes include handling trailing whitespace in treemap parsing, updating quadrant chart lexer to accept fractional zeros, fixing inline comment handling in quadrant and XY charts, and correcting Venn diagram lexer keyword matching to allow hyphenated identifiers.
• [pull/8524, pull/8514, pull/8559, pull/8561]

• State and flowchart diagram stability fixes: Pull requests fix critical bugs causing rendering hangs or infinite loops in state and flowchart diagrams. These include preventing invalid parent-child state assignments to avoid layout cycles, disallowing empty state IDs after "as" to prevent rendering errors, and removing cyclic ancestor memberships in subgraphs to stop infinite render loops.
• [pull/8516, pull/8498, pull/8503]

• Community integrations documentation additions: Multiple pull requests add new tools and editors to the community integrations documentation. These include the Moxie Docs Mermaid editor with SQL-to-ER diagram generation, the MarkView Markdown reader with Mermaid rendering, the terminal markdown viewer "termd," and the Essential Designs Process Mapper integration.
• [pull/8519, pull/8520, pull/8550, pull/8554]

• Diagram layout and edge rendering fixes: Pull requests improve layout and edge rendering accuracy in diagrams. Fixes include correcting dagre layout cluster extraction to prevent errors with nested clusters, preserving edge clipping points for diamond and circle nodes connecting to subgraphs, and fixing linkStyle index parsing in agentflow-beta diagrams to avoid type errors.
• [pull/8497, pull/8518, pull/8551]

• Markdown and style handling improvements: One pull request fixes nested bold and italic Markdown styles losing outer styles when htmlLabels is false by introducing a new strongEm type. Another adds support for comma-separated node IDs in flowchart style statements, applying styles individually while preserving existing attributes.
• [pull/8502, pull/8506]

3.2 Closed Pull Requests

This section provides a summary of pull requests that were closed in the repository over the past week. The top three pull requests with the highest number of commits are highlighted as 'key' pull requests. Other pull requests are grouped based on similar characteristics for easier analysis. Up to 25 pull requests are displayed in this section, while any remaining pull requests beyond this limit are omitted for brevity.

Pull Requests Closed This Week: 10

Key Closed Pull Requests

1. feat(grid): add placement and geometry engine (PR 1/5 in stack): This pull request introduces an internal grid placement and geometry engine for nested containers in the Mermaid project, providing a normalized placement model, deterministic nested grid geometry computation, transactional node commits, and focused tests while deferring edge routing, labels, public configuration, and integration with production layout registries.

• URL: pull/8356

• Associated Commits: adb53, 300d4, 9f4f8, a0b90, aefb0, 5cb54, 682eb, 7c4bd, ccdcd, d086f, 5b455, f03a5, d734d, 944d0, de0db, 3bef1, 5a6fd, 55a0c

2. feat(shapes): add the BPMN element shapes: This pull request adds nine BPMN element shape renderers—including events, gateways, activities, data objects, data stores, and annotations—implemented as individual files over a shared core, featuring fixed geometry, inline glyphs drawn from the OMG notation, precise edge docking, and comprehensive tests to ensure correct rendering and interaction within the mermaid diagramming framework.

• URL: pull/8165

• Associated Commits: 5c8aa, 30729, e2d24, c9eee, 2f5ae, 03528

3. fix(swimlanes): do not draw a lane that a shared node emptied: This pull request fixes the swimlanes layout by preventing the drawing of empty lanes that result when a node shared between multiple top-level lanes is retained only in the first lane, adds warnings to log these conflicts including cases with nested subgraphs rendered as plain boxes, and updates the documentation and tests to reflect these behaviors.

• URL: pull/8405

• Associated Commits: b4299, 42dc2, 99ac7, d3126, db938

Other Closed Pull Requests

• Diagram rendering fixes and enhancements: Multiple pull requests improve diagram rendering by fixing use-case relationship labels to display UML guillemets and adding new unfilled edge markers like open arrowheads and hollow circles for BPMN message flows. These changes enhance visual accuracy and support for various diagram notations without altering existing syntax or introducing domain-specific logic.
• pull/8402, pull/8164

• Community integrations and documentation updates: Pull requests add new tools such as Glim, a macOS file viewer for Mermaid blocks, to the community integrations and productivity tools documentation. Another pull request intended to add Visual Mermaid for Confluence was withdrawn and not merged, reflecting ongoing efforts to expand and refine community resources.
• pull/8455, pull/8534

• Bug fixes and grammar improvements: Fixes include correcting the C4 diagram detector regex to avoid false positives by ensuring it only matches diagrams starting with specific keywords, and updating the quadrant chart lexer grammar to properly parse float coordinates like 1.0 or 1.00 while rejecting invalid values. These changes improve parsing accuracy and robustness with added tests and patches.
• pull/8501, pull/8513

• GitHub workflow and label management: A pull request addresses an issue where the "run pr tests" label was not created for pull requests from fork branches by adding a new GitHub workflow to generate labels on PR creation, including retry handling and removal of redundant label jobs. This improves automation and consistency in PR labeling.
• pull/8565

3.3 Pull Request Discussion Insights

This section will analyze the tone and sentiment of discussions within this project's open and closed pull requests that occurred within the past week. It aims to identify potentially heated exchanges and to maintain a constructive project environment.

Based on our analysis, there are no instances of toxic discussions in the project's open or closed pull requests from the past week.

IV. Contributors

4.1 Contributors

Active Contributors:

We consider an active contributor in this project to be any contributor who has made at least 1 commit, opened at least 1 issue, created at least 1 pull request, or made more than 2 comments in the last month.

If there are more than 10 active contributors, the list is truncated to the top 10 based on contribution metrics for better clarity.