feat: pass some chart options to DateAdapter

src/core/core.adapters.js

@@ -26,8 +26,9 @@ function abstract() {
 
 export class DateAdapter {
 
-  constructor(options) {
+  constructor(options, chartOptions) {
     this.options = options || {};
+    this.chartOptions = chartOptions || {};
   }
 
   /**

src/scales/scale.time.js

@@ -221,7 +221,10 @@ export default class TimeScale extends Scale {
 
   init(scaleOpts, opts) {
     const time = scaleOpts.time || (scaleOpts.time = {});
-    const adapter = this._adapter = new adapters._date(scaleOpts.adapters.date);
+    const adapterChartOpts = {
+      locale: opts.locale
+    };
+    const adapter = this._adapter = new adapters._date(scaleOpts.adapters.date, adapterChartOpts);
 
     // Backward compatibility: before introducing adapter, `displayFormats` was
     // supposed to contain *all* unit/string pairs but this can't be resolved

test/specs/scale.time.tests.js

@@ -1235,4 +1235,37 @@ describe('Time scale tests', function() {
       });
     });
   });
+
+  it('should pass default locale to date adapter', function() {
+    var chart = window.acquireChart({
+      type: 'line',
+      data: {},
+      options: {
+        scales: {
+          x: {
+            type: 'time'
+          },
+        }
+      }
+    });
+
+    expect(chart.scales.x._adapter.chartOptions.locale).toBe('en-US');
+  });
+
+  it('should pass locale to date adapter from options', function() {
+    var chart = window.acquireChart({
+      type: 'line',
+      data: {},
+      options: {
+        locale: 'es',
+        scales: {
+          x: {
+            type: 'time'
+          },
+        }
+      }
+    });
+
+    expect(chart.scales.x._adapter.chartOptions.locale).toBe('es');
+  });
 });

types/adapters.d.ts

@@ -4,6 +4,9 @@ export interface DateAdapter {
   // Override one or multiple of the methods to adjust to the logic of the current date library.
   override(members: Partial<DateAdapter>): void;
   readonly options: unknown;
+  readonly chartOptions: {
+    locale?: string;
+  };
 
   /**
    * Returns a map of time formats for the supported formatting units defined