Start v3 migration guide (#6639)

docs/SUMMARY.md

@@ -6,6 +6,7 @@
   * [Installation](getting-started/installation.md)
   * [Integration](getting-started/integration.md)
   * [Usage](getting-started/usage.md)
+  * [Migration Guide](getting-started/v3-migration.md)
 * [General](general/README.md)
   * [Accessibility](general/accessibility.md)
   * [Responsive](general/responsive.md)

docs/getting-started/v3-migration.md

@@ -0,0 +1,70 @@
+# Chart.js 3.x Migration Guide
+
+Chart.js 3.0 introduces a number of breaking changes. Chart.js 2.0 was released in April 2016. In the years since then, as Chart.js has grown in popularity and feature set, we've learned some lessons about how to better create a charting library. In order to improve performance, offer new features, and improve maintainability it was necessary to break backwards compatibility, but we aimed to do so only when necessary.
+
+## Eng user migration
+
+### Ticks
+
+* `options.ticks.userCallback` was renamed to `options.ticks.callback`
+
+### Tooltip
+
+* `xLabel` and `yLabel` were removed. Please use `index` and `value`
+
+### Interactions
+
+* `options.onClick` is now limited to the chart area
+* `{mode: 'single'}` was replaced with `{mode: 'nearest', intersect: true}`
+* `{mode: 'label'}` was replaced with `{mode: 'index'}`
+* `modes['X-axis']` was replaced with `{mode: 'index', intersect: false}`
+
+### Customizability
+
+* `custom` attribute of elements was removed. Please use scriptable options
+
+### Options
+
+* `scales.[x/y]Axes.barPercentage` was moved to dataset option `barPercentage`
+* `scales.[x/y]Axes.barThickness` was moved to dataset option `barThickness`
+* `scales.[x/y]Axes.categoryPercentage` was moved to dataset option `categoryPercentage`
+* `scales.[x/y]Axes.minBarLength` was moved to dataset option `minBarLength`
+* `scales.[x/y]Axes.maxBarThickness` was moved to dataset option `maxBarThickness`
+* `scales.[x/y]Axes.time.format` was renamed to `scales.[x/y]Axes.time.parser`
+* `scales.[x/y]Axes.time.min` was renamed to `scales.[x/y]Axes.ticks.min`
+* `scales.[x/y]Axes.time.max` was renamed to `scales.[x/y]Axes.ticks.max`
+
+## Developer migration
+
+### Removed
+
+* `afterScaleUpdate`
+* `helpers.addEvent`
+* `helpers.aliasPixel`
+* `helpers.configMerge`
+* `helpers.indexOf`
+* `helpers.numberOfLabelLines`
+* `helpers.removeEvent`
+* `helpers.scaleMerge`
+* `scale.mergeTicksOptions`
+* `Chart.Controller`
+* `Chart.chart.chart`
+* `Chart.types`
+
+### Renamed
+
+* `helpers.clear` was renamed to `helpers.canvas.clear`
+* `helpers.drawRoundedRectangle` was renamed to `helpers.canvas.roundedRect`
+* `helpers.callCallback` was renamed to `helpers.callback`
+* `helpers.getValueOrDefault` was renamed to `helpers.valueOrDefault`
+* `helpers.getValueAtIndexOrDefault` was renamed to `helpers.valueAtIndexOrDefault`
+* `helpers.easingEffects` was renamed to `helpers.easing.effects`
+* `helpers.log10` was renamed to `helpers.math.log10`
+* `Chart.Animation.animationObject` was renamed to `Chart.Animation`
+* `Chart.Animation.chartInstance` was renamed to `Chart.Animation.chart`
+
+### Changed
+
+#### Time Scale
+
+* `getValueForPixel` now returns milliseconds since the epoch

src/helpers/helpers.easing.js

@@ -2,7 +2,7 @@
 
 /**
  * Easing functions adapted from Robert Penner's easing equations.
- * @namespace Chart.helpers.effects
+ * @namespace Chart.helpers.easing.effects
  * @see http://www.robertpenner.com/easing/
  */
 var effects = {