fix: improve Chart component

src/components/Chart/__test__/chart.spec.js

@@ -8,6 +8,10 @@ jest.mock('../helpers/unregisterGlobalPlugins', () => jest.fn());
 
 jest.mock('../chart', () =>
     jest.fn(() => ({
+        data: {
+            labels: [],
+            datasets: [],
+        },
         update: jest.fn(),
         config: {},
     })),
@@ -25,18 +29,13 @@ describe('<Chart />', () => {
             type: 'line',
             data: {
                 labels: ['A', 'B', 'C', 'D'],
-                datasets: [expect.any(Object)],
             },
             plugins: null,
             options: expect.any(Object),
         });
     });
     it('should call ChartJS update method to update the chart when the component changes', () => {
-        const component = mount(
-            <Chart labels={['A', 'B', 'C', 'D']} type="line">
-                <Dataset values={[34, 345, 234, 234]} title="Dataset 1" />
-            </Chart>,
-        );
+        const component = mount(<Chart labels={['A', 'B', 'C', 'D']} type="line" />);
         const { chartInstance } = component.instance();
         component.setProps({
             labels: ['A', 'B', 'C', 'D', 'E'],
@@ -46,16 +45,12 @@ describe('<Chart />', () => {
     });
 
     it('should call ChartJS update method to update the chart when the children changes', () => {
-        const component = mount(
-            <Chart labels={['A', 'B', 'C', 'D']} type="line">
-                <Dataset values={[34, 345, 234, 234]} title="Dataset 1" />
-            </Chart>,
-        );
+        const component = mount(<Chart labels={['A', 'B', 'C', 'D']} type="line" />);
         const { chartInstance } = component.instance();
         component.setProps({
             children: [<Dataset values={[34, 345, 234, 234, 90]} title="Dataset 1" />],
         });
-        expect(chartInstance.update).toHaveBeenCalledTimes(1);
+        expect(chartInstance.update).toHaveBeenCalledTimes(2);
     });
 
     it('should update the chart type when changed dynamically', () => {

src/components/Chart/context.js

@@ -0,0 +1,4 @@
+import React from 'react';
+
+const ChartContext = React.createContext();
+export default ChartContext;

src/components/Chart/index.js

@@ -3,9 +3,10 @@ import PropTypes from 'prop-types';
 import { withTheme } from 'styled-components';
 import ChartJS from './chart';
 import resolveOptions from './resolveOptions';
-import resolveDatasets from './resolveDatasets';
 import StyledContainer from './styled/container';
+import DatasetContainer from './styled/datasetContainer';
 import unregisterGlobalPlugins from './helpers/unregisterGlobalPlugins';
+import ChartContext from './context';
 
 /**
  * A chart is a graphical representation of data. Charts allow users to better understand
@@ -18,36 +19,48 @@ export class Chart extends Component {
     constructor(props) {
         super(props);
         this.chartRef = React.createRef();
-        this.datasets = [];
+        this.datasets = {};
+        this.registerDataset = this.registerDataset.bind(this);
+        this.unregisterDataset = this.unregisterDataset.bind(this);
+        this.updateDataset = this.updateDataset.bind(this);
     }
 
     componentDidMount() {
-        const { children } = this.props;
-        this.datasets = resolveDatasets(children);
         this.renderChart();
     }
 
     componentDidUpdate() {
-        const { children } = this.props;
-        this.datasets = resolveDatasets(children);
         this.updateChart();
     }
 
     updateChart() {
         const { labels, type, ...conditions } = this.props;
-        this.chartInstance.data = {
-            labels,
-            datasets: this.datasets,
-        };
+        this.chartInstance.config.type = type;
+        this.chartInstance.data.labels = labels;
+        this.chartInstance.data.datasets = Object.values(this.datasets);
+        this.chartInstance.options = resolveOptions({ type, ...conditions });
+        this.chartInstance.update();
+    }
 
-        if (type && this.chartInstance.config && type !== this.chartInstance.config.type) {
-            this.chartInstance.config.type = type;
-        }
+    registerDataset(id, dataset) {
+        this.datasets[id] = dataset;
+        this.updateChart();
+    }
 
-        this.chartInstance.options = resolveOptions({ type, ...conditions });
+    unregisterDataset(id) {
+        const { [id]: remove, ...rest } = this.datasets;
+        this.datasets = rest;
         this.chartInstance.update();
     }
 
+    updateDataset(id, dataset) {
+        const keys = Object.keys(dataset);
+        keys.forEach(key => {
+            this.datasets[id][key] = dataset[key];
+        });
+        this.updateChart();
+    }
+
     renderChart() {
         unregisterGlobalPlugins(ChartJS);
         const { type, labels, plugins, ...conditions } = this.props;
@@ -57,20 +70,27 @@ export class Chart extends Component {
             type,
             data: {
                 labels,
-                datasets: this.datasets,
             },
             plugins: plugins || null,
             options: resolveOptions({ type, plugins, ...conditions }),
         });
     }
 
     render() {
-        const { style, className } = this.props;
+        const { style, className, children } = this.props;
+        const context = {
+            registerDataset: this.registerDataset,
+            unregisterDataset: this.unregisterDataset,
+            updateDataset: this.updateDataset,
+        };
 
         return (
-            <StyledContainer className={className} style={style}>
-                <canvas ref={this.chartRef} />
-            </StyledContainer>
+            <ChartContext.Provider value={context}>
+                <StyledContainer className={className} style={style}>
+                    <canvas ref={this.chartRef} />
+                    <DatasetContainer>{children}</DatasetContainer>
+                </StyledContainer>
+            </ChartContext.Provider>
         );
     }
 }

src/components/Chart/styled/datasetContainer.js

@@ -0,0 +1,7 @@
+import styled from 'styled-components';
+
+const StyledDatasetContainer = styled.div`
+    display: none;
+`;
+
+export default StyledDatasetContainer;

src/components/Dataset/__test__/dataset.spec.js

@@ -0,0 +1,78 @@
+import React from 'react';
+import { mount } from 'enzyme';
+import Dataset from '..';
+
+const context = {
+    registerDataset: jest.fn(),
+    unregisterDataset: jest.fn(),
+    updateDataset: jest.fn(),
+};
+
+describe('<Dataset />', () => {
+    beforeEach(() => {
+        jest.resetAllMocks();
+        React.useContext = jest.fn().mockReturnValue(context);
+    });
+
+    it('should call registerDataset with dataset props', () => {
+        mount(
+            <Dataset
+                title="Dataset 1"
+                values={[1, 2, 3]}
+                backgroundColor="#ccc"
+                borderColor="#000"
+                stack="stack-1"
+                type="line"
+            />,
+        );
+        expect(context.registerDataset).toHaveBeenCalledWith(expect.any(String), {
+            label: 'Dataset 1',
+            data: [1, 2, 3],
+            backgroundColor: '#ccc',
+            borderColor: '#000',
+            stack: 'stack-1',
+            type: 'line',
+            fill: false,
+        });
+    });
+
+    it('should call unregisterDataset when unmounted', () => {
+        const wrapper = mount(
+            <Dataset
+                title="Dataset 1"
+                values={[1, 2, 3]}
+                backgroundColor="#ccc"
+                borderColor="#000"
+                stack="stack-1"
+                type="line"
+            />,
+        );
+        wrapper.unmount();
+        expect(context.unregisterDataset).toHaveBeenCalledTimes(1);
+    });
+
+    it('should call updateDataset when props changes', () => {
+        const wrapper = mount(
+            <Dataset
+                title="Dataset 1"
+                values={[1, 2, 3]}
+                backgroundColor="#ccc"
+                borderColor="#000"
+                stack="stack-1"
+                type="line"
+            />,
+        );
+        wrapper.setProps({
+            values: [4, 5, 6],
+        });
+        expect(context.updateDataset).toHaveBeenCalledWith(expect.any(String), {
+            label: 'Dataset 1',
+            data: [4, 5, 6],
+            backgroundColor: '#ccc',
+            borderColor: '#000',
+            stack: 'stack-1',
+            type: 'line',
+            fill: false,
+        });
+    });
+});

src/components/Dataset/index.js

@@ -1,10 +1,44 @@
 /* eslint-disable react/no-unused-prop-types */
-import React from 'react';
+import React, { useEffect, useRef } from 'react';
 import PropTypes from 'prop-types';
+import ChartContext from '../Chart/context';
+import { useUniqueIdentifier } from '../../libs/hooks';
 
 /** @category DataView */
-export default function Dataset() {
-    return <div />;
+export default function Dataset(props) {
+    const datasetId = useUniqueIdentifier('dataset');
+    const { title: label, values: data, ...rest } = props;
+    const { registerDataset, unregisterDataset, updateDataset } = React.useContext(ChartContext);
+    const isRegistered = useRef();
+
+    useEffect(() => {
+        if (isRegistered.current) {
+            updateDataset(datasetId, {
+                label,
+                data,
+                ...rest,
+            });
+        }
+    });
+
+    useEffect(() => {
+        registerDataset(datasetId, {
+            label,
+            data,
+            ...rest,
+        });
+        isRegistered.current = true;
+
+        return () => {
+            if (isRegistered.current) {
+                unregisterDataset(datasetId);
+                isRegistered.current = false;
+            }
+        };
+        // eslint-disable-next-line react-hooks/exhaustive-deps
+    }, []);
+
+    return <></>;
 }
 
 Dataset.propTypes = {