Weekly GitHub Report for Mermaid

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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 a new Radar Chart feature, enhancing the visualization capabilities of the platform. This addition reflects ongoing efforts to expand charting options for users.

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. [TYPE: QUESTION] [STATUS: DISCUSSION NEEDED] Feature Request: Allow subgraphs to have different directions than the main graph (e.g., LR inside TD): This issue requests the ability for subgraphs in Mermaid diagrams to have independent directional flows (such as left-to-right inside a top-down main graph), which is currently unsupported and limits diagram flexibility. Users discuss whether this limitation is a bug or a feature gap, with explanations revealing that subgraph directions are overridden when edges connect external nodes directly to internal subgraph nodes, causing inconsistent behavior.

   • The comments clarify that subgraph direction works in the flowchart syntax but is overridden when external edges connect to internal nodes rather than the subgraph itself, effectively merging directions; users confirm this is a bug or unstable feature, share examples and workarounds, and express ongoing need for a proper fix, including a shared experimental patch.
   • Number of comments this week: 2

2. [STATUS: TRIAGE] C4 diagrams: unified renderer migration and c4-beta - PR series tracker: This issue tracks the comprehensive modernization and migration of the C4 diagram rendering system in Mermaid, replacing the legacy row-grid renderer with a unified rendering pipeline that supports real layout engines, theming, tagging, icons, links, and legends, alongside introducing a new structurizr-inspired c4-beta syntax. It organizes the work into phased pull request batches covering foundational migration slices (shapes, edges, layout), new syntax and theming, legacy parity features, new C4 concepts, and final convergence, with detailed progress updates, review feedback, and community issue triage documented throughout.

   • The comment discussion provides ongoing status updates on the phased PR merges, addresses review feedback from maintainers and the C4 creator, confirms resolved conflicts, triages related community issues, and reports on CI and visual test results, with no outstanding review threads or contributor-side blockers remaining.
   • Number of comments this week: 2

3. [CONTRIBUTOR NEEDED] [STATUS: APPROVED] [TYPE: NEW DIAGRAM] Organizational Charts: This issue requests enhancements to the graph diagram type in Mermaid to better support organizational charts, specifically by allowing the addition of same-level nodes linked only to other nodes with control over their positioning, and by providing an option to force links to avoid diagonal lines for cleaner layouts. The discussion in the comments expands on these ideas, suggesting the creation of a new diagram type dedicated to org charts with features like node attributes for names, headshots, dotted reporting lines, and assistant nodes to more accurately represent organizational structures.

   • Commenters generally support the request, proposing alternatives like using flowcharts or state diagrams, and emphasize the need for features such as node attributes, dotted lines for matrix reporting, and assistant nodes; some share examples and external libraries, highlighting the demand for a specialized org chart diagram type in Mermaid.
   • Number of comments this week: 1

4. [TYPE: ENHANCEMENT] [CONTRIBUTOR NEEDED] [CLOSE AFTER 30 DAYS] [P1] Export to Powerpoint/Google Slides: This issue requests a feature to export Mermaid-generated flowcharts directly into editable PowerPoint or Google Slides files, allowing users to modify text and nodes within those applications as if the charts were created natively there. The user acknowledges the technical challenges but emphasizes the value such functionality would add by differentiating Mermaid from competitors and improving workflow efficiency.

   • The comments express strong support for the feature, discuss potential technical approaches including generating pptx files with libraries like PptxGenJS, and note limitations imposed by PowerPoint and Google Slides on SVG editing. Some contributors suggest focusing on an interchange format like JSON for easier integration, while others share existing tools that convert SVGs into editable PowerPoint shapes, highlighting both the complexity and interest in achieving editable exports.
   • Number of comments this week: 1

5. [TYPE: ENHANCEMENT] [STATUS: TRIAGE] [TYPE: NEW DIAGRAM] Causal Loop Diagrams: This issue proposes adding support for Causal Loop Diagrams (CLDs) to the Mermaid diagramming tool, highlighting their importance in visualizing dynamic systems through feedback loops and causal relationships. The proposal details specific visual and functional requirements for CLDs, such as circular edges, labeled relationships, loop annotations, and delay indicators, and includes references and examples to guide implementation.

   • The comments provide additional resources and examples related to systems thinking and CLDs, discuss challenges in representing CLDs within Mermaid’s flowchart style, share existing workarounds and external tools for CLDs, and express interest in native support and integration with other platforms.
   • 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: 8

Summarized Issues:

• Rendering Bugs in Diagrams: Several issues describe rendering failures or bugs in different diagram types, including Gantt charts failing with a TypeError on tasks with many metadata items, flowcharts failing during the Dagre layout phase when edges target subgraph IDs, and treemap diagrams failing to parse due to trailing whitespace after numeric leaf values. These bugs cause either internal errors or parse failures that prevent proper rendering until corrected.
• issues/8188, issues/8202, issues/8205

• Feature Enhancements for Diagram Types: Proposals include adding native support for waveform and timing diagrams to describe signal transitions and timing relationships, and adding a configuration option to GitGraph to allow branch lane reuse when branches merge without new commits. These enhancements aim to improve diagram expressiveness and reduce visual complexity in specific use cases.
• issues/8187, issues/8208

• Configuration and Documentation Improvements: One issue highlights a silent omission of default keys in the defaultConfig.class configuration causing schema and runtime discrepancies, while another requests adding an Agent-Friendly Score badge to the README to showcase the project's score. These address maintenance clarity and project presentation respectively.
• issues/8195, issues/8218

• Diagram Labeling and Layout Issues: An issue reports improper handling of long labels in the database shape actor of sequence diagrams, resulting in poor centering and lack of padding. This affects the visual correctness and readability of sequence diagrams.
• issues/8215

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: 3

Summarized Issues:

• Initialization and Compatibility Issues: Mermaid version 11.17.0 fails to initialize and throws a TypeError when a global define function exists on the page, an issue not present in version 11.16.1. This problem affects the library's compatibility with certain global environments, causing unexpected crashes during startup.
• issues/8095

• Test Execution Failures in CI: Scoped end-to-end test runs fail immediately in the CI pipeline because the detectScope script emits glob patterns that Playwright misinterprets as regular expressions, resulting in syntax errors. This prevents tests from running and disrupts the continuous integration process.
• issues/8102

• Dependency and Type Checking Errors: The pnpm test:check:tsc command intermittently fails due to unpinned dependencies on type-fest and typescript, causing type errors from incompatible versions and missing types like Float16Array. The issue suggests aligning dependency versions with the main project and improving error logging to resolve these problems.
• issues/8179

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: 11

Key Open Pull Requests

1. Release/12.0.0: This pull request introduces major new features and improvements to the Mermaid diagramming library, most notably making the ELK layout engine the default and bundled layout algorithm, adding new diagram types such as UML use case and agentflow-beta diagrams, enhancing ELK layout and rendering with fixes and new configuration options, and applying the redux color palette to agentflow and block diagrams, collectively modernizing Mermaid’s layout capabilities, expanding diagram variety, and improving rendering consistency and accessibility.

• URL: pull/8211

• Associated Commits: 5d90f, 0dc0d, 5f9ce, 99525, 756ae, b134d, 7ee4c, d4bea, 1246a, 1befa, 3b092, a2448, 6f9e8, 785ca, 5e8f8, 68a70, 5099c, aa72e, fef9e, 294c3, 7f911, 8d565, 1348b, cd8b6, b4463, 9bd2e, db17c, f5af4, ce030, d1a19, 524b7, 25b2b, adc63, 31e62, b02f1, cb9e0, 5f501, 0ad30, b8325, 63440, 38024, 53f45, 721b8, 2878c, 5f8ef, 0454b, 94b02, 90534, 0ec29, e94c3, cac6b, c1c11, 2120b, 62064, 121ca, 13bd7, 48d83, 82def, 3d258, 29354, 6485d, 20afb, 22779, 813c7, 20d4a, 1eb23, 1634e, 24ddc, 6fc90, a2a62, 012e1, be6fa, b2de3, 90d57, 0afa5, 5ff81, c4b51, c5d4b, ca8fc, 8c066, e36ef, 7e284, d76e2, c8a4b, e947c, 3569e, 846fd, 5660f, ea819, 2bac3, 238c2, fef70, 828ed, 72519, b9939, 44f65, 563d1, f8037, cbc68, bfc03, 1cebd, d2274, 9018d, 1d01a, a240b, b8e6f, b4253, 59c61, 91036, 7a804, 29597, 23a12, 236a9, 78001, e5287, 8cc33, 9b3fc, d6a4f, cf8d2, 32775, a3788, 4e00c, fa6a8, a7831, b9fa6, 0d75e, 03204, ee33b, fe0e2, a31ec, 93edd, 1488b, 9cbba, e23d0, 9d618, 3d010, 3a8b3, d46cb, 21304, 66420, f4d14, e1fb5, 92876, 24068, 4ec49, b979e, 503b5, a19bd, 33cf3

2. feat(gitGraph): add option to reuse branch lanes: This pull request introduces a new optional configuration reuseBranchLanes for Git Graph diagrams in Mermaid, enabling the reuse of lanes from merged branches without subsequent commits to prevent ultra-wide diagrams, while adding branch lifetime tracking, lane allocation logic, comprehensive tests, documentation, and maintaining default behavior to avoid regressions.

• URL: pull/8209

• Associated Commits: 53863, 08a38, 253a2, b2e41, 192c0, 07186, b79b8, eb180, 32a86, a8d1c, 52e9a, 0163b, c2558, 25282, 4a4b3, d09c1, 52a12

3. fix(flowchart): parse CSS comments in style and linkStyle: This pull request adds lexer support to the Mermaid flowchart parser for properly tokenizing complete CSS comments within style and linkStyle declarations as NODE_STRING, ensuring that comments containing spaces, Unicode characters, commas, brackets, and quotes are preserved correctly while rejecting unterminated comments, and includes new parser tests and performance updates to resolve issue #7024.

• URL: pull/8207

• Associated Commits: d4994, e1619, a21cd, 550b5

Other Open Pull Requests

• Rendering and Diagram Fixes: Multiple pull requests address rendering issues in Mermaid diagrams, including fixing the scaling of the database participant shape's cylinder in sequence diagrams and removing leftover error diagram elements from failed parses to prevent document clutter. These fixes improve visual accuracy and error handling in the rendering process, enhancing the overall user experience.
• pull/8220, pull/8221

• Parser Improvements: Several pull requests improve the robustness of Mermaid's parsers by adding validation to the Gantt chart parser to reject invalid task metadata and updating the treemap diagram parser to allow optional trailing whitespace, preventing parse failures. These changes include clear diagnostic errors and regression tests to ensure stability and correctness.
• pull/8201, pull/8206

• Performance Optimization: A pull request replaces a quadratic backtracking regex with a linear scanner for front matter detection, significantly improving performance on hot paths while maintaining compatibility through extensive testing. This optimization enhances efficiency without sacrificing correctness.
• pull/8203

• Feature Addition - Mermaid Rendering in Node.js: A work-in-progress pull request introduces the ability to render Mermaid diagrams directly in Node.js by setting up a JSDOM environment with custom SVG text measurement estimators and exposing CSSStyleSheet for CSSOM support. It also provides CLI commands to render .mmd files to SVG and includes performance comparisons against Chromium, identifying key issues with font sizing and text-anchor handling.
• pull/8210

• Community Integration - IQ Mermaid Editor: A pull request adds IQ Mermaid, a free browser-based Mermaid editor supporting 34 interface languages and synchronized visual canvas, to the Community integrations list under Productivity tools. The editor allows .mmd file exports without server-side storage, enhancing accessibility and usability for users.
• pull/8217

• Dependency Upgrade - KaTeX: A pull request upgrades the KaTeX dependency to version 0.18.0, removes the obsolete @types/katex development dependency, and adds a minor changeset for the release. It notes that this update may break custom CSS targeting KaTeX, signaling a potential impact on styling.
• pull/8216

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: 20

Key Closed Pull Requests

1. feat(themes)!: make redux-color the default theme and neo the default look: This pull request makes the redux-color theme the new default and pairs it with the neo look as the default appearance for all diagrams rendered without explicit theme or look settings, while fixing several latent bugs exposed by this change, updating documentation, adding role-based and rotating color schemes for use case diagrams and swimlane lane coloring in redux themes, and ensuring consistent, validated theming behavior across the codebase with comprehensive tests and a major version release.

• URL: pull/8148

• Associated Commits: 8603b, 775a3, 5de52, bceca, da796, c3ee3, a66a5, c831b, 4b348, 46f1c, 12823, c7697, 2d33f, dbd5a, 75e6c, 55039, 0f793, e0e29

2. feature(layout): Update tests due to elk default layout: This pull request updates the test suite to replace the default layout from elk to dagre-layout, reflecting the change in the project's default flowchart layout and ensuring tests are aligned with this new default.

• URL: pull/8182

• Associated Commits: 6f7bc, ed78b, e7068, ad75b, 644fe, 03d78, a8bff, 352ce, fa4ba, 0e2a5, fefa1, 377aa, 37c50

3. feat(layout)!: bundle ELK and make it the default layout: This pull request bundles the ELK layout algorithm into the core mermaid package and makes it the default layout for most supported diagram types—replacing dagre—while preserving explicit layout overrides and maintaining cose-bilkent as the default for mindmaps, along with various fixes, optimizations, and test updates to support this integration.

• URL: pull/8155

• Associated Commits: 81089, 1a718, 8105f, cf03e, e98b0, f3488, e46e8, 55226, afe23, 6b6d4, f229f

Other Closed Pull Requests

• ELK Layout and Package Management: Multiple pull requests fix the Unknown arrow type: arrow_open warning by correcting arrow type mappings and refactor layout-related functions out of the main Mermaid package into @mermaid-js/layout-elk. They also enhance the preview publishing workflow to include all related packages with synchronized versions, add a browser-based release verification harness, update documentation about ELK’s default status and the tiny build’s role, and manage peer dependency declarations for upcoming major releases.
• [pull/8222, pull/8223, pull/8226]

• FastDOM Compatibility and Integration: Several pull requests address initialization failures caused by FastDOM’s UMD export resolving incorrectly when a global define is present by implementing a resilient core resolution fallback to window.fastdom. They vendor the fastdom-promised wrapper locally, add a minimal local fallback core, enhance typings and error handling, bundle and patch FastDOM into an ESM-compatible module, move it to a devDependency, and update integration to use direct ESM imports for compatibility and build stability.
• [pull/8109, pull/8154]

• Environment and Browser Support Updates: Pull requests update Mermaid’s environment requirements by mandating ES2024 support, setting Safari 17.4 as the minimum browser version, adding Chromium v121 and Firefox 123 as baseline targets, and enforcing Node.js 22.12 or higher. Additionally, linting support for WebKit 15.4 is added using eslint-plugin-compat to ensure compatibility in bundled source files, targeting the release/12.0.0 branch.
• [pull/8213, pull/8212]

• Documentation and Contributor Guides: Updates include rewriting the contributor guide for adding new diagrams to align with the current DiagramDefinition workflow and review checklist, introducing a comprehensive Layout Maker’s Guide covering layout data contracts and renderer stages, and documenting per-diagram default themes and looks with fixes to the documentation site for correct display in light and dark modes. These changes improve documentation accuracy, usability, and testing coverage.
• [pull/8115, pull/8193]

• Testing and CI Improvements: Pull requests fix end-to-end test scope detection by replacing invalid glob patterns with valid regex patterns for Playwright, resolve intermittent TypeScript check failures in CI by pinning type dependencies to exact versions, and fix the continuous integration pipeline by ensuring preview packages are published with explicit public access to avoid permission errors. These changes enhance test reliability and CI stability.
• [pull/8103, pull/8180, pull/8226]

• Theme and Palette Enhancements: Multiple pull requests improve theming by fixing Venn diagram color issues under redux-color themes, adding palette-based coloring to state diagram composite states and concurrency regions, refining default theme, look, and layout settings with per-diagram-type defaults, and fixing a rendering bug where note edges incorrectly appeared solid under the neo look by applying dashed styling. These include comprehensive unit and end-to-end tests to verify correct rendering and theming behavior.
• [pull/8189, pull/8190, pull/8191, pull/8192]

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.

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