Introduce minBarThickness on a bar chart

docs/charts/bar.md

@@ -89,6 +89,7 @@ Only the `data` option needs to be specified in the dataset namespace.
 | [`inflateAmount`](#inflateamount) | `number`\|`'auto'` | Yes | Yes | `'auto'`
 | [`maxBarThickness`](#maxbarthickness) | `number` | - | - | |
 | [`minBarLength`](#styling) | `number` | - | - | |
+| [`minBarThickness`](#minBarThickness) | `number` | - | - | |
 | [`label`](#general) | `string` | - | - | `''`
 | [`order`](#general) | `number` | - | - | `0`
 | [`pointStyle`](../configuration/elements.md#point-styles) | [`pointStyle`](../configuration/elements.md#types) | Yes | - | `'circle'`
@@ -107,6 +108,7 @@ data: {
         barPercentage: 0.5,
         barThickness: 6,
         maxBarThickness: 8,
+        minBarThickness: 1,
         minBarLength: 2,
         data: [10, 20, 30, 40, 50, 60, 70]
     }]
@@ -215,6 +217,10 @@ If not set (default), the base sample widths are calculated using the smallest i
 
 Set this to ensure that bars are not sized thicker than this.
 
+### minBarThickness
+
+Set this to ensure that bars have at least the specified thickness. When `maxBarThickness` and `minBarThickness` have conflicting values, `maxBarThickness` is used.
+
 ## Scale Configuration
 
 The bar chart sets unique default values for the following configuration from the associated `scale` options:

src/controllers/controller.bar.js

@@ -617,6 +617,7 @@ export default class BarController extends DatasetController {
     const options = this.options;
     const skipNull = options.skipNull;
     const maxBarThickness = valueOrDefault(options.maxBarThickness, Infinity);
+    const minBarThickness = valueOrDefault(options.minBarThickness, -Infinity);
     let center, size;
     if (ruler.grouped) {
       const stackCount = skipNull ? this._getStackCount(index) : ruler.stackCount;
@@ -626,11 +627,11 @@ export default class BarController extends DatasetController {
 
       const stackIndex = this._getStackIndex(this.index, this._cachedMeta.stack, skipNull ? index : undefined);
       center = range.start + (range.chunk * stackIndex) + (range.chunk / 2);
-      size = Math.min(maxBarThickness, range.chunk * range.ratio);
+      size = Math.min(maxBarThickness, Math.max(minBarThickness, range.chunk * range.ratio));
     } else {
       // For non-grouped bar charts, exact pixel values are used
       center = scale.getPixelForValue(this.getParsed(index)[scale.axis], index);
-      size = Math.min(maxBarThickness, ruler.min * ruler.ratio);
+      size = Math.min(maxBarThickness, Math.max(minBarThickness, ruler.min * ruler.ratio));
     }
 
     return {

src/types/index.d.ts

@@ -128,6 +128,11 @@ export interface BarControllerDatasetOptions
    */
   maxBarThickness: number;
 
+  /**
+   * Set this to ensure that bars have at least the specified thickness.
+   */
+  minBarThickness: number;
+
   /**
    * Set this to ensure that bars have a minimum length in pixels.
    */

test/specs/controller.bar.tests.js

@@ -1531,6 +1531,21 @@ describe('Chart.controllers.bar', function() {
             expect(meta.data[1].width).toBeCloseToPixel(10);
           }
         });
+
+        it('should correctly set bar width if minBarThickness is specified', function() {
+          var chart = this.chart;
+          var i, ilen, meta;
+
+          chart.data.datasets[0].minBarThickness = 1000;
+          chart.data.datasets[1].minBarThickness = 1000;
+          chart.update();
+
+          for (i = 0, ilen = chart.data.datasets.length; i < ilen; ++i) {
+            meta = chart.getDatasetMeta(i);
+            expect(meta.data[0].width).toBeCloseToPixel(1000);
+            expect(meta.data[1].width).toBeCloseToPixel(1000);
+          }
+        });
       });
     });
   });