add candlestick helper methods jest tests

Author: heythisispaul

packages/victory-candlestick/src/index.js

@@ -1,2 +1,3 @@
 export { default as VictoryCandlestick } from "./victory-candlestick";
 export { default as Candle } from "./candle";
+export * as helperMethods from "./helper-methods";

test/jest/victory-candlestick/helper-methods.test.js

@@ -0,0 +1,77 @@
+/* eslint max-nested-callbacks: 0 */
+import { helperMethods } from "victory-candlestick";
+import { range } from "lodash";
+import { fromJS } from "immutable";
+
+const immutableGetDataTest = {
+  createData: (x) => fromJS(x),
+  testLabel: "with immutable data"
+};
+const getDataTest = {
+  createData: (x) => x,
+  testLabel: "with js data"
+};
+
+const { getData, getDomain } = helperMethods;
+
+[getDataTest, immutableGetDataTest].forEach(({ createData, testLabel }) => {
+  describe(`victory-candlestick/helper-methods ${testLabel}`, () => {
+    describe("getData", () => {
+      it("sorts data by sortKey", () => {
+        const data = createData(
+          range(5)
+            .map((i) => ({ x: i, open: i, close: i, high: i, low: i }))
+            .reverse()
+        );
+
+        const dataResult = getData({
+          data,
+          x: "x",
+          open: "open",
+          close: "close",
+          high: "high",
+          low: "low",
+          sortKey: "x"
+        });
+
+        expect(dataResult.map((datum) => datum.x)).toEqual([0, 1, 2, 3, 4]);
+      });
+    });
+
+    describe("getDomain", () => {
+      const dataSet = createData([
+        { x: 5, open: 10, close: 20, high: 25, low: 5 },
+        { x: 10, open: 15, close: 25, high: 30, low: 10 }
+      ]);
+
+      it("returns a domain array for the x axis", () => {
+        const domainXResult = getDomain(
+          {
+            data: dataSet,
+            x: "x",
+            open: "open",
+            close: "close",
+            high: "high",
+            low: "low"
+          },
+          "x"
+        );
+        expect(domainXResult).toEqual([5, 10]);
+      });
+
+      it("returns a domain array for the y axis", () => {
+        const domainYResult = getDomain(
+          {
+            data: dataSet,
+            open: "open",
+            close: "close",
+            high: "high",
+            low: "low"
+          },
+          "y"
+        );
+        expect(domainYResult).toEqual([5, 30]);
+      });
+    });
+  });
+});