Adding target and source branch env variables for pull requests

docs/user-guide/Templating.md

@@ -13,6 +13,8 @@ DotCi provides the following global variables:
 * `GIT_URL` - git url
 * `DOTCI_PUSHER` - github username whose git push triggred this build
 * `DOTCI_PULL_REQUEST` - pull request number being built
+* `DOTCI_PULL_REQUEST_SOURCE_BRANCH` - the pull request branch
+* `DOTCI_PULL_REQUEST_TARGET_BRANCH` - the branch the pull request is targeting
 
 ## Groovy templating
 

src/main/java/com/groupon/jenkins/dynamic/build/cause/BuildCause.java

@@ -25,14 +25,9 @@ of this software and associated documentation files (the "Software"), to deal
 
 import com.groupon.jenkins.git.GitBranch;
 import com.groupon.jenkins.github.Payload;
-import com.jcraft.jsch.jce.MD5;
 import hudson.model.Cause;
 
-import java.io.UnsupportedEncodingException;
 import java.math.BigInteger;
-import java.nio.charset.StandardCharsets;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -56,6 +51,7 @@ public abstract class BuildCause extends Cause {
     public abstract String getPullRequestNumber();
 
     public abstract CommitInfo getCommitInfo();
+
     @Exported
     public abstract String getName();
 
@@ -67,7 +63,7 @@ public Map<String, String> getEnvVars() {
         return vars;
     }
 
-    private static void putIfNotNull(Map<String, String> vars, String key, String value) {
+    protected static void putIfNotNull(Map<String, String> vars, String key, String value) {
         if (value != null) {
             vars.put(key, value);
         }
@@ -88,6 +84,7 @@ public static class CommitInfo{
         private String branch;
         private final String sha;
         private String commitUrl;
+
         //for backward compat
         private CommitInfo(){
             this.committerEmail = "[email protected]";

src/main/java/com/groupon/jenkins/dynamic/build/cause/GitHubPullRequestCause.java

@@ -25,15 +25,29 @@ of this software and associated documentation files (the "Software"), to deal
 
 import com.groupon.jenkins.github.Payload;
 
+import java.util.Map;
+
 public class GitHubPullRequestCause extends GithubCause {
     private final String label;
     private final String number;
+    private final String targetBranch;
+    private final String sourceBranch;
 
-    public GitHubPullRequestCause(Payload payload, String sha, String label, String number) {
+    public GitHubPullRequestCause(Payload payload, String sha, String label, String number, String sourceBranch, String targetBranch) {
         super(payload, sha);
         this.label = label;
         this.number = number;
+        this.targetBranch = targetBranch;
+        this.sourceBranch = sourceBranch;
+
+    }
 
+    @Override
+    public Map<String, String> getEnvVars() {
+        Map vars = super.getEnvVars();
+        putIfNotNull(vars, "DOTCI_PULL_REQUEST_TARGET_BRANCH", getTargetBranch());
+        putIfNotNull(vars, "DOTCI_PULL_REQUEST_SOURCE_BRANCH", getSourceBranch());
+        return vars;
     }
 
     @Override
@@ -45,4 +59,12 @@ public String getShortDescription() {
     public String getName() {
         return "GITHUB_PULL_REQUEST";
     }
+
+    public String getTargetBranch() {
+        return targetBranch;
+    }
+
+    public String getSourceBranch() {
+        return sourceBranch;
+    }
 }

src/main/java/com/groupon/jenkins/github/GithubWebhook.java

@@ -28,7 +28,6 @@ of this software and associated documentation files (the "Software"), to deal
 import com.groupon.jenkins.dynamic.build.DynamicProject;
 import com.groupon.jenkins.dynamic.build.repository.DynamicProjectRepository;
 import hudson.Extension;
-import hudson.model.AbstractProject;
 import hudson.model.Job;
 import hudson.model.ParameterDefinition;
 import hudson.model.ParameterValue;

src/main/java/com/groupon/jenkins/github/Payload.java

@@ -50,8 +50,7 @@ public Cause getCause() {
             JSONObject pullRequest = getPullRequest();
             final String label = pullRequest.getJSONObject("head").getString("label");
             String number = pullRequest.getString("number");
-            return new GitHubPullRequestCause(this, getSha(), label, number);
-
+            return new GitHubPullRequestCause(this, getSha(), label, number, getPullRequestSourceBranch(), getPullRequestTargetBranch());
         } else {
             final String pusherName = payloadJson.getJSONObject("pusher").getString("name");
             final String email = payloadJson.getJSONObject("pusher").getString("email");
@@ -97,6 +96,20 @@ private boolean isPullRequestFromWithinSameRepo() {
         return headRepoUrl.equals(pullRequestRepoUrl);
     }
 
+    public String getPullRequestSourceBranch() {
+        if (!isPullRequest()) {
+            return null;
+        }
+        return getPullRequest().getJSONObject("head").getString("ref");
+    }
+
+    public String getPullRequestTargetBranch() {
+        if (!isPullRequest()) {
+            return null;
+        }
+        return getPullRequest().getJSONObject("base").getString("ref");
+    }
+
     public String getBranchDescription() {
         if (isPullRequest()) {
             return "Pull Request " + getPullRequestNumber();

src/test/java/com/groupon/jenkins/dynamic/build/cause/BuildCauseTest.java

@@ -51,6 +51,19 @@ public void should_export_env_vars() {
         assertEquals("44", cause.getEnvVars().get("DOTCI_PULL_REQUEST"));
     }
 
+    @Test
+    public void should_export_pr_env_vars() {
+        GitHubPullRequestCause cause = mock(GitHubPullRequestCause.class);
+        doCallRealMethod().when(cause).getEnvVars();
+
+        doReturn("feature").when(cause).getSourceBranch();
+        doReturn("master").when(cause).getTargetBranch();
+
+        assertNotNull(cause.getEnvVars());
+        assertEquals("feature", cause.getEnvVars().get("DOTCI_PULL_REQUEST_SOURCE_BRANCH"));
+        assertEquals("master", cause.getEnvVars().get("DOTCI_PULL_REQUEST_TARGET_BRANCH"));
+    }
+
     @Test
     public void should_export_not_export_null_env_vars() {
         BuildCause cause = mock(BuildCause.class);