1 files changed, 98 insertions, 0 deletions
diff --git a/__test__/github-api-helper.test.ts b/__test__/github-api-helper.test.ts
new file mode 100644
index 0000000..6319e20
--- /dev/null
+++ b/__test__/github-api-helper.test.ts
@@ -0,0 +1,98 @@
+import * as core from '@actions/core'
+import * as github from '@actions/github'
+import * as githubApiHelper from '../lib/github-api-helper'
+
+describe('github-api-helper object format', () => {
+  let getOctokitSpy: jest.SpyInstance
+  let debugSpy: jest.SpyInstance
+  let request: jest.Mock
+
+  function mockHashAlgorithmApi(hashAlgorithm: string): void {
+    request = jest.fn(async () => ({
+      data: {
+        hash_algorithm: hashAlgorithm
+      }
+    }))
+    getOctokitSpy = jest.spyOn(github, 'getOctokit').mockReturnValue({
+      request
+    } as any)
+  }
+
+  beforeEach(() => {
+    debugSpy = jest.spyOn(core, 'debug').mockImplementation(jest.fn())
+  })
+
+  afterEach(() => {
+    jest.restoreAllMocks()
+  })
+
+  it('detects SHA-256 from the repository hash algorithm endpoint', async () => {
+    mockHashAlgorithmApi('sha256')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: 'sha256', succeeded: true})
+
+    expect(getOctokitSpy).toHaveBeenCalledWith(
+      'token',
+      expect.objectContaining({baseUrl: 'https://api.github.com'})
+    )
+    expect(request).toHaveBeenCalledWith(
+      'GET /repos/{owner}/{repo}/hash-algorithm',
+      {owner: 'owner', repo: 'repo'}
+    )
+  })
+
+  it('detects SHA-1 from the repository hash algorithm endpoint', async () => {
+    mockHashAlgorithmApi('sha1')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: 'sha1', succeeded: true})
+  })
+
+  it('detects object format from an existing commit without API calls', async () => {
+    const commitSha =
+      '9422233ca7ee1b17f1e905d0e141faf0c401556c41cdc6acd71c6bd685da2e92'
+    getOctokitSpy = jest.spyOn(github, 'getOctokit')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat(
+        'token',
+        'owner',
+        'repo',
+        undefined,
+        commitSha
+      )
+    ).resolves.toEqual({format: 'sha256', succeeded: true})
+
+    expect(getOctokitSpy).not.toHaveBeenCalled()
+  })
+
+  it('returns unsuccessful when the hash algorithm endpoint value is not recognized', async () => {
+    mockHashAlgorithmApi('unknown')
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: '', succeeded: false})
+    expect(debugSpy).toHaveBeenCalledWith(
+      'Unable to determine repository object format from hash-algorithm endpoint'
+    )
+  })
+
+  it('returns unsuccessful when the hash algorithm API lookup fails', async () => {
+    request = jest.fn(async () => {
+      throw new Error('not found')
+    })
+    jest.spyOn(github, 'getOctokit').mockReturnValue({
+      request
+    } as any)
+
+    await expect(
+      githubApiHelper.tryGetRepositoryObjectFormat('token', 'owner', 'repo')
+    ).resolves.toEqual({format: '', succeeded: false})
+    expect(debugSpy).toHaveBeenCalledWith(
+      'Unable to determine repository object format from hash-algorithm endpoint: not found'
+    )
+  })
+})