Improve code quality and write tests

node_modules/codecov/lib/services/azurePipelines.js

@@ -0,0 +1,23 @@
+module.exports = {
+  detect: function() {
+    return !!process.env.TF_BUILD
+  },
+
+  configuration: function() {
+    console.log('    Azure Pipelines CI Detected')
+    return {
+      service: 'azure_pipelines',
+      commit: process.env.BUILD_SOURCEVERSION,
+      branch: process.env.BUILD_SOURCEBRANCH,
+      pr: process.env.SYSTEM_PULLREQUEST_PULLREQUESTNUMBER,
+      job: process.env.SYSTEM_JOBID,
+      build: process.env.BUILD_BUILDID,
+      build_url:
+        process.env.SYSTEM_TEAMFOUNDATIONSERVERURI +
+        process.env.SYSTEM_TEAMPROJECT +
+        '/_build/results?buildId=' +
+        process.env.BUILD_BUILDID,
+      slug: process.env.BUILD_REPOSITORY_ID,
+    }
+  },
+}