test: added test & refactored files

tests/fetchStats.test.js

@@ -0,0 +1,66 @@
+require("@testing-library/jest-dom");
+const axios = require("axios");
+const MockAdapter = require("axios-mock-adapter");
+const fetchStats = require("../src/fetchStats");
+
+const data = {
+  data: {
+    user: {
+      name: "Anurag Hazra",
+      repositoriesContributedTo: { totalCount: 61 },
+      contributionsCollection: { totalCommitContributions: 100 },
+      pullRequests: { totalCount: 300 },
+      issues: { totalCount: 200 },
+      repositories: {
+        nodes: [
+          { stargazers: { totalCount: 100 } },
+          { stargazers: { totalCount: 100 } },
+          { stargazers: { totalCount: 100 } },
+          { stargazers: { totalCount: 50 } },
+          { stargazers: { totalCount: 50 } },
+        ],
+      },
+    },
+  },
+};
+
+const error = {
+  errors: [
+    {
+      type: "NOT_FOUND",
+      path: ["user"],
+      locations: [],
+      message: "Could not resolve to a User with the login of 'noname'.",
+    },
+  ],
+};
+
+const mock = new MockAdapter(axios);
+
+afterEach(() => {
+  mock.reset();
+});
+
+describe("Test fetchStats", () => {
+  it("should fetch correct stats", async () => {
+    mock.onPost("https://api.github.com/graphql").reply(200, data);
+
+    let stats = await fetchStats("anuraghazra");
+    expect(stats).toStrictEqual({
+      contributedTo: 61,
+      name: "Anurag Hazra",
+      totalCommits: 100,
+      totalIssues: 200,
+      totalPRs: 300,
+      totalStars: 400,
+    });
+  });
+
+  it("should throw error", async () => {
+    mock.onPost("https://api.github.com/graphql").reply(200, error);
+
+    await expect(fetchStats("anuraghazra")).rejects.toThrow(
+      "Could not fetch user"
+    );
+  });
+});