Unit tests for loading/downloading a config file

When we support the configuration file feature we have to
execute one more step in our workflow - checking if a Precaution
configuration file exists and downloading it from the repository.

Also, when we add new config options we should test them if we
use them correctly in our workflow.

Signed-off-by: Martin Vrachev <mvrachev@vmware.com>

filter.js

@@ -26,7 +26,7 @@ function isExcluded (filePath, excludes) {
 /**
  * Filters the listed files and returns only the files relevant to us
  * @param {*} rawData the raw output from list files API call
- * @param {String[]} excludes excludes globs provided by the user to filter files/folders
+ * @param {String[]} excludes array of exclusion rules in glob format provided by the user
  * @return {Promise[]<any>} the filtered GitHub response
  */
 function filterData (rawData, excludes) {
@@ -45,3 +45,4 @@ function filterData (rawData, excludes) {
 }
 
 module.exports.filterData = filterData
+module.exports.isExcluded = isExcluded

github_api_helper.js

@@ -31,10 +31,11 @@ function inProgressAPIresponse (context, headSha) {
  * Get Precaution config file contents as raw data,
  * if that file exists.
  * @param {import('probot').Context} context Probot context
+ * @param {String} customConfigPath Optional (default value config.configFilePath)
  * @return {Promise<any>} GitHub response
  * See https://developer.github.com/v3/repos/contents/#get-contents
  */
-async function getConfigFile (context) {
+async function getConfigFile (context, customConfigPath = config.configFilePath) {
   let { owner, repo } = context.repo()
   // GitHub doesn't provide "checkIfFileExists" API endpoint.
   // That's why we should try to download the file and if we have
@@ -43,7 +44,7 @@ async function getConfigFile (context) {
     return await context.github.repos.getContents({
       owner,
       repo,
-      path: config.configFilePath,
+      path: customConfigPath,
       headers: { accept: rawMediaType }
     })
   } catch (error) {

test/fixtures/pull_request.files.mix.json

@@ -27,6 +27,15 @@
     {
       "filename": "executable",
       "status": "added"
+    },
+    {
+      "filename":"tests/func/funcTest.go"
+    },
+    {
+      "filename":"src/commands/command_test.go"
+    },
+    {
+      "filename":"src/cmd/main.py"
     }
   ]
 }

test/index.test.js

@@ -118,6 +118,40 @@ describe('Precaution workflow', () => {
       }))
     })
 
+    test('Checks the downloading of a config file', async () => {
+      await app.receive(pullRequestOpenedEvent)
+
+      expect(github.repos.getContents).toHaveBeenCalledWith(expect.objectContaining({
+        owner: 'owner_login',
+        repo: 'repo_name',
+        path: config.configFilePath
+      }))
+    })
+
+    test('Check for a repo without config file', async () => {
+      const { getConfigFile } = require('../github_api_helper')
+      let context = {
+        repo: jest.fn().mockResolvedValue({
+          owner: 'owner_login',
+          repo: 'repo_name'
+        }),
+        github: {
+          repos: {
+            getContents: jest.fn(({ path }) => {
+              if (mockFiles.hasOwnProperty(path)) {
+                return Promise.resolve({ data: mockFiles[path] })
+              } else {
+                let error = new Error(path + ' fixture does not exist')
+                error.code = 404
+                throw error
+              }
+            })
+          }
+        }
+      }
+      expect(await getConfigFile(context, 'customConfig.json')).toEqual(null)
+    })
+
     test('Check run rerequest event', async () => {
       await app.receive(checkRunRerequestEvent)
 
@@ -230,6 +264,15 @@ describe('Precaution workflow', () => {
       expect(github.repos.getContents).not.toHaveBeenCalledWith(expect.objectContaining({
         path: 'executable'
       }))
+      expect(github.repos.getContents).not.toHaveBeenCalledWith(expect.objectContaining({
+        path: 'tests/func/funcTest.go'
+      }))
+      expect(github.repos.getContents).not.toHaveBeenCalledWith(expect.objectContaining({
+        path: 'src/commands/command_test.go'
+      }))
+      expect(github.repos.getContents).not.toHaveBeenCalledWith(expect.objectContaining({
+        path: 'src/cmd/main.py'
+      }))
     })
 
     test('handles PRs with only deletions', async () => {