Merge pull request #310 from qmfrederik/features/travis

Add Travis CI support

Author: AArnott

src/NerdBank.GitVersioning/CloudBuild.cs

@@ -19,6 +19,7 @@ public static class CloudBuild
             new AtlassianBamboo(), 
             new Jenkins(),
             new GitLab(),
+            new Travis(),
         };
 
         /// <summary>

src/NerdBank.GitVersioning/CloudBuildServices/Travis.cs

@@ -0,0 +1,37 @@
+namespace Nerdbank.GitVersioning.CloudBuildServices
+{
+    using System;
+    using System.Collections.Generic;
+    using System.IO;
+
+    /// <summary>
+    /// Travis CI build support.
+    /// </summary>
+    /// <remarks>
+    /// The Travis CI environment variables referenced here are documented here:
+    /// https://docs.travis-ci.com/user/environment-variables/#default-environment-variables
+    /// </remarks>
+    internal class Travis: ICloudBuild
+    {
+        // TRAVIS_BRANCH can reference a branch or a tag, so make sure it starts with refs/heads
+        public string BuildingBranch => CloudBuild.ShouldStartWith(Environment.GetEnvironmentVariable("TRAVIS_BRANCH"), "refs/heads/");
+
+        public string BuildingTag => Environment.GetEnvironmentVariable("TRAVIS_TAG");
+
+        public string GitCommitId => Environment.GetEnvironmentVariable("TRAVIS_COMMIT");
+
+        public bool IsApplicable => !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("TRAVIS"));
+
+        public bool IsPullRequest => !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("TRAVIS_PULL_REQUEST_BRANCH"));
+
+        public IReadOnlyDictionary<string, string>  SetCloudBuildNumber(string buildNumber, TextWriter stdout, TextWriter stderr)
+        {
+            return new Dictionary<string, string>();
+        }
+
+        public IReadOnlyDictionary<string, string> SetCloudBuildVariable(string name, string value, TextWriter stdout, TextWriter stderr)
+        {
+            return new Dictionary<string, string>();
+        }
+    }
+}