Add TODO tracking file for plotly.js upgrade

Tracks:
- Potential regressions to test (pie rotation, selection events, SVG export, etc.)
- Potential improvements/new features to expose in R package

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cpsievert

PLOTLYJS_UPGRADE_TODO.md

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+# plotly.js Upgrade TODO
+
+Items to address following the upgrade from v2.11.1 to v2.25.2.
+
+---
+
+## Potential Regressions to Test
+
+These changes in plotly.js could potentially cause regressions in existing R package functionality. Each should be tested to ensure the R package continues to work as expected.
+
+### HIGH PRIORITY
+
+- [ ] **Pie chart rotation behavior** (v2.15.0)
+  - Change: Updated pie chart `rotation` to use `angle` value type
+  - Risk: Existing R code using pie chart rotation may behave differently
+  - Test: Create pie charts with rotation values and compare before/after behavior
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.15.0
+
+- [ ] **Selection event changes** (v2.13.0, v2.13.1, v2.13.2, v2.13.3)
+  - Change: Major overhaul of selection handling - persistent/editable selections, `plotly_selected` event now emits on API calls and GUI edits
+  - Risk: Shiny event handlers relying on selection events may receive different/additional events
+  - Test: Test `event_data("plotly_selected")` in Shiny apps, ensure brushing behavior is unchanged
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.13.0
+
+- [ ] **SVG export scaling** (v2.18.1)
+  - Change: Removed vector-effect CSS for static plots to fix SVG export scaling
+  - Risk: Static image export via kaleido/orca may produce different results
+  - Test: Export plots to SVG and compare rendering
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.18.1
+
+### MEDIUM PRIORITY
+
+- [ ] **Multiple legend defaults** (v2.22.0, v2.24.2, v2.24.3)
+  - Change: Added multiple legend support; several fixes to legend group/trace order defaults
+  - Risk: Existing plots with legendgroups may have different default ordering
+  - Test: Create plots with multiple legend groups and verify appearance
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.22.0
+
+- [ ] **Automargin behavior changes** (v2.13.0, v2.15.0)
+  - Change: More flexible `automargin` control on cartesian axes; fixed automargin axis title updates
+  - Risk: Plot margins may differ slightly from previous versions
+  - Test: Run visual regression tests on plots with long axis labels/titles
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.13.0
+
+- [ ] **Hover label overlap fix** (v2.19.0)
+  - Change: Fixed hover label overlap for `hovermode: 'x'` or `'y'`
+  - Risk: Hover label positioning may change for existing plots
+  - Test: Create plots with multiple traces and verify hover labels don't overlap
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.19.0
+
+### LOW PRIORITY
+
+- [ ] **Bundle size changes** (v2.17.0)
+  - Change: Switched bundler from browserify to webpack
+  - Risk: Bundle size may have changed; performance characteristics may differ
+  - Test: Compare bundle sizes, check for any performance regressions
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.17.0
+
+- [ ] **Static plot interactions** (v2.15.0, v2.16.5)
+  - Change: Disabled interactions for static plot modes in treemap, icicle, sunburst; disabled slider interactions when staticPlot is true
+  - Risk: `config(staticPlot = TRUE)` may behave differently
+  - Test: Verify static plots are truly non-interactive
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.15.0
+
+- [ ] **Heatmap rendering changes** (v2.21.0, v2.23.0, v2.23.1)
+  - Change: Fixed heatmap `zsmooth: "fast"` rendering/performance; improved rendering when zsmooth is false; fixed iOS/Safari rendering
+  - Risk: Visual differences in heatmap rendering
+  - Test: Run visual tests on heatmaps with different zsmooth settings
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.21.0
+
+---
+
+## Potential Improvements / New Features
+
+These are new plotly.js features that could be exposed or better supported in the R package. Not critical, but would enhance functionality.
+
+### Legend Improvements
+
+- [ ] **Multiple legends** (v2.22.0)
+  - Feature: Support for `legend2`, `legend3`, etc. with separate positioning
+  - R Impact: Could document how to use multiple legends via `layout()`
+  - Priority: Medium - significant new capability
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.22.0
+
+- [ ] **Legend visibility control** (v2.22.0)
+  - Feature: Added `visible` option for legends
+  - R Impact: Could add to `layout()` documentation
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.22.0
+
+- [ ] **Legend entry width** (v2.15.0)
+  - Feature: `entrywidth` and `entrywidthmode` for legend items
+  - R Impact: Document in legend customization examples
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.15.0
+
+- [ ] **Shape legends** (v2.25.0)
+  - Feature: Legends can now include shapes and `newshape`
+  - R Impact: Could enhance shape documentation
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.25.0
+
+### Axis/Layout Features
+
+- [ ] **Grid dash styling** (v2.12.0)
+  - Feature: `griddash` axis property for cartesian, polar, smith, ternary, geo, carpet
+  - R Impact: Document new grid styling options
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.12.0
+
+- [ ] **Minor tick styling** (v2.12.0)
+  - Feature: `minor.tickmode`, `minor.tickvals`, `minor.tickcolor`, etc.
+  - R Impact: Could add helper functions or documentation for minor tick customization
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.12.0
+
+- [ ] **Y-axis shift/autoshift** (v2.17.0)
+  - Feature: `shift` and `autoshift` properties to avoid y-axis overlapping
+  - R Impact: Document for multi-y-axis plots
+  - Priority: Medium - useful for complex plots
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.17.0
+
+- [ ] **Sync tickmode** (v2.18.0)
+  - Feature: New `sync` tickmode option for synchronized axes
+  - R Impact: Document for subplots with shared axes
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.18.0
+
+- [ ] **Label alias** (v2.19.0)
+  - Feature: `labelalias` for various axes types
+  - R Impact: Could simplify axis label customization
+  - Priority: Medium - useful feature
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.19.0
+
+- [ ] **Title automargin** (v2.20.0)
+  - Feature: `title.automargin` for automatic top/bottom margining
+  - R Impact: Could reduce need for manual margin adjustments
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.20.0
+
+### Trace/Chart Features
+
+- [ ] **Violin quartile methods** (v2.13.0)
+  - Feature: Additional quartile computing algorithms for violin traces
+  - R Impact: Could expose new quartile method options in violin trace helpers
+  - Priority: Medium - enhances existing functionality
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.13.0
+
+- [ ] **Marker angle properties** (v2.15.0)
+  - Feature: `marker.angle`, `marker.angleref`, `marker.standoff`
+  - R Impact: Could enhance marker customization documentation or helpers
+  - Priority: Medium - useful for directional data
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.15.0
+
+- [ ] **Scatter grouping** (v2.17.0)
+  - Feature: `alignmentgroup` and `offsetgroup` for scatter traces
+  - R Impact: Could enhance grouped scatter plot support
+  - Priority: Medium - useful for grouped comparisons
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.17.0
+
+- [ ] **Sankey arrows** (v2.14.0)
+  - Feature: Support for sankey links with arrows
+  - R Impact: Document new sankey link options
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.14.0
+
+- [ ] **Treemap corner radius** (v2.17.0)
+  - Feature: `marker.cornerradius` for treemap trace
+  - R Impact: Document styling option
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.17.0
+
+- [ ] **Pattern support expansion** (v2.24.0)
+  - Feature: Pattern support for pie, funnelarea, sunburst, icicle, and treemap charts
+  - R Impact: Document pattern fill options for these chart types
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.24.0
+
+### Shape Features
+
+- [ ] **Shape labels** (v2.19.0, v2.21.0)
+  - Feature: Shape `label` attribute and `label.texttemplate` for parametric shapes
+  - R Impact: Could enhance shape annotation helpers
+  - Priority: Medium - commonly requested feature
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.19.0
+
+### Geo/Map Features
+
+- [ ] **Equal Earth projection** (v2.25.0)
+  - Feature: New "Equal Earth" projection for geo subplots
+  - R Impact: Document new projection option for `plot_geo()`
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.25.0
+
+- [ ] **Scattermapbox clustering** (v2.16.0)
+  - Feature: Clustering options and bounds support for scattermapbox
+  - R Impact: Document clustering for `plot_mapbox()`
+  - Priority: Medium - useful for large datasets
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.16.0
+
+### Selection/Interaction Features
+
+- [ ] **Editable selections** (v2.13.0, v2.14.0)
+  - Feature: Persistent and editable selections; `editSelection` config option
+  - R Impact: Could expose via `config()` and document for Shiny apps
+  - Priority: Medium - enhances interactivity
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.13.0
+
+### Indicator Features
+
+- [ ] **Delta prefix/suffix** (v2.13.0)
+  - Feature: `delta.prefix` and `delta.suffix` for indicator traces
+  - R Impact: Document for indicator trace customization
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.13.0
+
+### Parallel Coordinates
+
+- [ ] **Unselected line styling** (v2.13.0)
+  - Feature: Unselected line color/opacity options
+  - R Impact: Document for parallel coordinates customization
+  - Priority: Low
+  - Ref: https://github.com/plotly/plotly.js/releases/tag/v2.13.0
+
+---
+
+## Testing Checklist
+
+Before merging the upgrade:
+
+- [ ] Run full test suite: `devtools::test()`
+- [ ] Run visual tests: `Sys.setenv("VISUAL_TESTS" = "true"); devtools::test()`
+- [ ] Run R CMD check: `rcmdcheck::rcmdcheck()`
+- [ ] Test basic Shiny integration with event_data()
+- [ ] Manually test key plot types: scatter, bar, pie, heatmap, geo, mapbox
+- [ ] Compare bundle size before/after
+- [ ] Test static image export via kaleido
+
+---
+
+## Notes
+
+- The IE9/phantomjs compatibility patch (001-revert-ie-fallbacks.patch) continues to apply successfully through all versions
+- Security fix in v2.25.2 addresses prototype pollution - important for production use
+- Many locale updates throughout the versions (Dutch, French, Norwegian, Slovak, Croatian, etc.)