Feature/tests-for-data-fetcher (#266)

* jest config

* Create utils.test.ts

* shared and utils test

* chore: Add Run-Tests job to deploy.yml

* Revert "chore: Add Run-Tests job to deploy.yml"

This reverts commit 5ac1860.

* create workflow for unit tests

* Update unit-tests.yml

* update test file matcher

---------

Co-authored-by: Dina Basumatary <[email protected]>

.github/workflows/unit-tests.yml

@@ -0,0 +1,16 @@
+name: Unit Tests
+
+on: [push, pull_request]
+
+jobs:
+  run-unit-tests:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Install Dependencies
+      run: npm install
+
+    - name: Run Unit Tests
+      run: npm test

data/__tests__/shared.test.ts

@@ -0,0 +1,206 @@
+import { Repository, Source } from "../../types";
+import { getGitHubRepositories } from "../github";
+import { getFilteredLanguages, getFilteredTags, processSource } from "../shared";
+import { dummyRepositories } from "./test-data";
+
+jest.mock("../github");
+
+describe("shared", () => {
+  describe("processSource", () => {
+    it("returns an empty array when given an empty source", async () => {
+      const source: Source = {
+        name: "Empty Source",
+        provider: "github",
+        repositories: [],
+        labels: []
+      };
+      const result = await processSource(source);
+      expect(result).toEqual([]);
+    });
+
+    it("returns an array of repositories when given a source with repositories", async () => {
+      const source: Source = {
+        name: "React Repositories",
+        provider: "github",
+        repositories: ["facebook/react", "airbnb/react-dates"],
+        labels: []
+      };
+      (getGitHubRepositories as jest.Mock).mockResolvedValueOnce([
+        {
+          name: "React",
+          url: "https://github.com/facebook/react",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "React Dates",
+          url: "https://github.com/airbnb/react-dates",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [
+            { id: "ui", display: "UI" },
+            { id: "calendar", display: "Calendar" }
+          ]
+        }
+      ]);
+      const result = await processSource(source);
+      expect(result).toEqual([
+        {
+          name: "React",
+          url: "https://github.com/facebook/react",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "React Dates",
+          url: "https://github.com/airbnb/react-dates",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [
+            { id: "ui", display: "UI" },
+            { id: "calendar", display: "Calendar" }
+          ]
+        }
+      ]);
+    });
+  });
+
+  describe("getFilteredLanguages", () => {
+    it("returns an empty array when given an empty array of repositories", () => {
+      const result = getFilteredLanguages([]);
+      expect(result).toEqual([]);
+    });
+
+    it("returns an array of CountableLanguage objects when given an array of repositories", () => {
+      const result = getFilteredLanguages(dummyRepositories);
+      expect(result).toEqual([{ id: "python", display: "Python", count: 3 }]);
+    });
+
+    it("filters out languages with less than 3 repositories and sorts the remaining languages alphabetically", () => {
+      const repositories = [
+        {
+          name: "Angular1",
+          url: "https://github.com/angular/angular",
+          language: { id: "typescript", display: "TypeScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "Angular2",
+          url: "https://github.com/angular/angular",
+          language: { id: "typescript", display: "TypeScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "React",
+          url: "https://github.com/facebook/react",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "React Dates",
+          url: "https://github.com/airbnb/react-dates",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [
+            { id: "ui", display: "UI" },
+            { id: "calendar", display: "Calendar" }
+          ]
+        },
+        {
+          name: "Vue.js",
+          url: "https://github.com/vuejs/vue",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "Angular",
+          url: "https://github.com/angular/angular",
+          language: { id: "typescript", display: "TypeScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        }
+      ] as Repository[];
+      const result = getFilteredLanguages(repositories);
+      console.log(result);
+      expect(result).toEqual([
+        { id: "javascript", display: "JavaScript", count: 3 },
+        { id: "typescript", display: "TypeScript", count: 3 }
+      ]);
+    });
+  });
+
+  describe("getFilteredTags", () => {
+    it("returns an empty array when given an empty array of repositories", () => {
+      const result = getFilteredTags([]);
+      expect(result).toEqual([]);
+    });
+
+    it("returns an array of CountableTag objects when given an array of repositories", () => {
+      const repositories = [
+        {
+          name: "React",
+          url: "https://github.com/facebook/react",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "React Dates",
+          url: "https://github.com/airbnb/react-dates",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [
+            { id: "ui", display: "UI" },
+            { id: "calendar", display: "Calendar" }
+          ]
+        },
+        {
+          name: "Vue.js",
+          url: "https://github.com/vuejs/vue",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        }
+      ] as Repository[];
+      const result = getFilteredTags(repositories);
+      expect(result).toEqual([{ id: "ui", display: "UI", count: 3 }]);
+    });
+
+    it("filters out tags with less than 3 repositories and sorts the remaining tags by count descending", () => {
+      const repositories = [
+        {
+          name: "React",
+          url: "https://github.com/facebook/react",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [{ id: "ui", display: "UI" }]
+        },
+        {
+          name: "React Dates",
+          url: "https://github.com/airbnb/react-dates",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [
+            { id: "ui", display: "UI" },
+            { id: "calendar", display: "Calendar" }
+          ]
+        },
+        {
+          name: "Vue.js",
+          url: "https://github.com/vuejs/vue",
+          language: { id: "javascript", display: "JavaScript" },
+          tags: [
+            { id: "ui", display: "UI" },
+            { id: "calendar", display: "Calendar" }
+          ]
+        },
+        {
+          name: "Angular",
+          url: "https://github.com/angular/angular",
+          language: { id: "typescript", display: "TypeScript" },
+          tags: [
+            { id: "ui", display: "UI" },
+            { id: "calendar", display: "Calendar" },
+            { id: "angular", display: "Angular" }
+          ]
+        }
+      ] as Repository[];
+      const result = getFilteredTags(repositories);
+      expect(result).toEqual([
+        { id: "ui", display: "UI", count: 4 },
+        { id: "calendar", display: "Calendar", count: 3 }
+      ]);
+    });
+  });
+});