add tests for chart module

tests/unit/chart.spec.js

@@ -0,0 +1,65 @@
+import { expect } from 'chai'
+import sinon from 'sinon'
+import * as chart from '@/chart'
+import * as dereference from 'react-chart-editor/lib/lib/dereference'
+
+describe('chart.js', () => {
+  it('getDataSourcesFromSqlResult', () => {
+    const sqlResult = {
+      columns: ['id', 'name'],
+      values: [
+        [1, 'foo'],
+        [2, 'bar']
+      ]
+    }
+
+    const ds = chart.getDataSourcesFromSqlResult(sqlResult)
+    expect(ds).to.eql({
+      id: [1, 2],
+      name: ['foo', 'bar']
+    })
+  })
+
+  it('getOptionsFromDataSources', () => {
+    const dataSources = {
+      id: [1, 2],
+      name: ['foo', 'bar']
+    }
+
+    const ds = chart.getOptionsFromDataSources(dataSources)
+    expect(ds).to.eql([
+      { value: 'id', label: 'id' },
+      { value: 'name', label: 'name' }
+    ])
+  })
+
+  it('getChartStateForSave', () => {
+    const state = {
+      data: {
+        foo: {},
+        bar: {}
+      },
+      layout: {},
+      frames: {}
+    }
+    const dataSources = {
+      id: [1, 2],
+      name: ['foo', 'bar']
+    }
+    sinon.stub(dereference, 'default')
+
+    const ds = chart.getChartStateForSave(state, dataSources)
+    
+    expect(dereference.default.calledOnce).to.equal(true)
+    
+    const args = dereference.default.firstCall.args
+    expect(args[0]).to.eql({
+      foo: {},
+      bar: {}
+    })
+    expect(args[1]).to.eql({
+      id: [],
+      name: []
+    })
+  })
+})