chore: add github tests (#4)

* add github tests

This adds tests of the 'github' module.

Signed-off-by: Mike Ball <[email protected]>

* remove line break

Signed-off-by: Mike Ball <[email protected]>

---------

Signed-off-by: Mike Ball <[email protected]>

src/github.test.js

@@ -1,21 +1,145 @@
 /* eslint-env jest */
-const core = require('@actions/core')
-// const github = require('./github')
+const github = require('./github')
 
-jest.spyOn(core, 'setOutput')
+const mockOctokit = {
+  request: jest.fn()
+}
+
+jest.spyOn(mockOctokit, 'request')
+
+jest.mock('@actions/github', () => {
+  return {
+    getOctokit: jest.fn(() => mockOctokit)
+  }
+})
 
 describe('github', () => {
-  beforeEach(() => {
+  describe('getOctokit', () => {
+    it('wraps @actions/github\'s getOctokit', () => {
+      expect(github.getOctokit()).toBe(mockOctokit)
+    })
+  })
+
+  describe('getLatestTag', () => {
+    let tag
+
+    afterEach(() => {
+      tag = undefined
+    })
+
+    describe('when the targeted repo has existing tags', () => {
+      beforeEach(async () => {
+        mockOctokit.request.mockImplementation(() => {
+          return {
+            data: ['1.0.0']
+          }
+        })
 
+        tag = await github.getLatestTag(mockOctokit, 'owner', 'repo')
+      })
+
+      it('fetches the repo\'s tags via the GitHub API', () => {
+        expect(mockOctokit.request).toHaveBeenCalledWith('GET /repos/{owner}/{repo}/tags?per_page=1', {
+          owner: 'owner',
+          repo: 'repo'
+        })
+      })
+
+      it('returns the latest tag returned by the GitHub API', () => {
+        expect(tag).toBe('1.0.0')
+      })
+    })
+
+    describe('when the targeted repo has no existing tags', () => {
+      beforeEach(async () => {
+        mockOctokit.request.mockImplementation(() => {
+          return {
+            data: []
+          }
+        })
+
+        tag = await github.getLatestTag(mockOctokit, 'owner', 'repo')
+      })
+
+      it('fetches the repo\'s tags via the GitHub API', () => {
+        expect(mockOctokit.request).toHaveBeenCalledWith('GET /repos/{owner}/{repo}/tags?per_page=1', {
+          owner: 'owner',
+          repo: 'repo'
+        })
+      })
+
+      it('returns undefined', () => {
+        expect(tag).toBe(undefined)
+      })
+    })
+
+    describe('when the underlying octokit API request fails', () => {
+      it('throws an error', async () => {
+        const result = 'error'
+
+        mockOctokit.request.mockRejectedValueOnce(result)
+
+        await expect(github.getLatestTag(mockOctokit, 'owner', 'repo')).rejects.toMatch(result)
+      })
+    })
   })
 
-  afterEach(() => {
-    jest.resetAllMocks()
+  describe('compareCommits', () => {
+    let result
+
+    beforeEach(async () => {
+      mockOctokit.request.mockImplementation(() => {
+        return {
+          data: {
+            commits: [{
+              sha: 'commit-sha',
+              commit: {
+                message: 'commit-message'
+              }
+            }]
+          }
+        }
+      })
+
+      result = await github.compareCommits(mockOctokit, 'owner', 'repo', 'base', 'head')
+    })
+
+    it('fetches a comparison of the specified base and head commits via the GitHub API', () => {
+      expect(mockOctokit.request).toHaveBeenCalledWith('GET /repos/{owner}/{repo}/compare/{basehead}', {
+        owner: 'owner',
+        repo: 'repo',
+        basehead: 'base...head'
+      })
+    })
+
+    it('returns a list of commits', () => {
+      expect(result).toStrictEqual([{
+        message: 'commit-message',
+        sha: 'commit-sha'
+      }])
+    })
   })
 
-  describe('setVersionOutputs()', () => {
-    it('should set output for all values', () => {
+  describe('createRelease', () => {
+    let result
+
+    beforeEach(async () => {
+      mockOctokit.request.mockImplementation(() => 'success')
+
+      result = await github.createRelease(mockOctokit, 'owner', 'repo', '1.0.0')
+    })
+
+    it('creates a release via the GitHub API', () => {
+      expect(mockOctokit.request).toHaveBeenCalledWith('POST /repos/{owner}/{repo}/releases', {
+        owner: 'owner',
+        repo: 'repo',
+        tag_name: '1.0.0',
+        generate_release_notes: true
+      })
+    })
 
+    it('returns the result of the underlying octokit GitHub API request', () => {
+      expect(result).toBe('success')
     })
   })
 })