This issue is to track my progress doing plotly.js-1.52 <--> Dash QA. My goal is to build Dash apps that use these features in order to surface potential issues Dash users might have with them.

[1.52.0] -- 2020-01-08

Added

• Add uniformtext behavior to bar, funnel, waterfall, pie, funnelarea,
  sunburst and treemap traces [Consistent text mode for bar-like & pie-like traces and feature to control text orientation inside pie/sunburst slices #4420, Fix uniformtext and enable coloraxis for sunburst and treemap as well as pathbar.textfont  #4444, Improve text fit in treemap trace #4469]
• Add "pre-computed" q1/median/q3 input signature for box traces [Box pre-computed q1/median/q3 input signature + more quartile-computing methods #4432]
• Add support for legend titles [Add title feature to legend and support legend option for various traces #4386]
• Add legend items for choropleth, choroplethmapbox, cone, densitymapbox,
  heatmap, histogram2d, isosurface, mesh3d, streamtube,
  surface, volume traces [Add title feature to legend and support legend option for various traces #4386, Fix image exports for new #4386 mocks with SVG gradients #4441]
• Add "auto-fitting" behavior to geo subplots via geo.fitbounds attribute [Geo improvements: fitbounds, 'geojson-id' locationmode and 'featureidkey' #4419]
• Add support for custom geojson geometries in choropleth
  and scattergeo traces [Geo improvements: fitbounds, 'geojson-id' locationmode and 'featureidkey' #4419]
• Add "exclusive" and "inclusive" quartile-computing algorithm to box traces
  via quartilemethod attribute [Box pre-computed q1/median/q3 input signature + more quartile-computing methods #4432]
• Add insidetextorientation attribute to pie and sunburst traces [Consistent text mode for bar-like & pie-like traces and feature to control text orientation inside pie/sunburst slices #4420]
• Add intensitymode to allow cell intensity values in mesh3d traces [Add intensitymode to allow cell intensity values in mesh3d #4446]
• Add featureidkey attribute to choroplethmapbox, choropleth
  and scattergeo traces [Geo improvements: fitbounds, 'geojson-id' locationmode and 'featureidkey' #4419]
• Add geo.visible shortcut attribute [Geo improvements: fitbounds, 'geojson-id' locationmode and 'featureidkey' #4419]
• Add coordinates of mapbox subplot view as a derived property in plotly_relayout
  event data [Add coordinates of mapbox view as a derived property in plotly_relayo… #4413]
• Add modebar buttons zoomInMapbox and zoomOutMapbox [Add modebar buttons zoomInMapbox and zoomOutMapbox #4398]
• Add support for typed array in groupby transforms groups [adding support for defining groups in data.transforms.groups using ty… #4410]
• Add notifyOnLogging config option that allows log/warn/error messages
  to show up in notifiers pop-ups [Notifier logging #4464]
• Enable loading locale bundles before plotly.js bundles [enables loading locales before Plotly #4453]
• Add Korean ko locale [translation to korean #4315]

Changed

• Skip mapbox subplot map position updates while panning/zooming removing
  potential stuttering [Mapbox react updates #4418]
• Optimize mapbox raster layout layer updates [Mapbox react updates #4418]
• Improve sunburst and treemap click events behavior [Improve sunbust and treemap click events behavior #4454]
• Improve attribute description of sunburst/treemap outsidetextfont [Improve description of sunburst/treemap outsidetextfont #4463]
• Update source and dist file headers to 2020 [update 2020 headers #4457]

Fixed

• Fix streamtube traces with numeric string coordinates
  (bug introduced in 1.51.0) [Handle streamtube coordinates in string format and handle different data orders in isosurface and volume #4431]
• Correctly handle different data orders in isosurface and volume traces [Handle streamtube coordinates in string format and handle different data orders in isosurface and volume #4431]
• Fix symbol numbers in scattergl and splom traces [Fix symbol numbers in scattergl and splom traces #4465]
• Fix coloraxis colorbars for sunburst and treemap with
  values colorscales [Fix uniformtext and enable coloraxis for sunburst and treemap as well as pathbar.textfont  #4444]
• Fix inside text fitting for bar, funnel and waterfall traces with
  set textangle [Fix uniformtext and enable coloraxis for sunburst and treemap as well as pathbar.textfont  #4444]
• Fix handling of invalid values and zero totals for pie and funnelarea [Handle invalid values and zero totals for pie and funnelarea #4416]
• Fix colorbar of reversescale colorscales of heatmap-coloring contours [Fix colorbar of reversescale colorbars of heatmap-coloring contours #4437]
• Fix colorbar templating for "non-root" colorscales [Fix colorbar templating for "non-root" colorscales #4470]
• Fix event data and some hover templates for x/y/z heatmap + contour [Fix event data and some hover templates for x/y/z heatmap + contour #4472]
• Fix "toggleothers" behavior for graphs with traces not in legend [Fix *toggleothers* behavior for graphs with traces not in legend #4406]
• Fix histogram bingroup logic when calendars module is not registered [Fix histogram bingroup algo when calendars module is not registered #4439]
• Fix "almost equal" branchvalue: 'total' partial sum cases [Add ALMOST_EQUAL tolerance in branchvalue:total partial sum check #4442]
• Fix handling of treemap pathbar.textfont [Fix uniformtext and enable coloraxis for sunburst and treemap as well as pathbar.textfont  #4444]