- add support for signed commits

- add support for required number of reviews

src/main/java/org/kohsuke/github/GHBranch.java

@@ -67,7 +67,7 @@ public URL getProtectionUrl() {
 
     @Preview @Deprecated
     public GHBranchProtection getProtection() throws IOException {
-        return root.retrieve().withPreview(LOKI).to(protection_url, GHBranchProtection.class);
+        return root.retrieve().withPreview(LOKI).to(protection_url, GHBranchProtection.class).wrap(this);
     }
 
     /**
@@ -82,7 +82,7 @@ public String getSHA1() {
      */
     @Preview @Deprecated
     public void disableProtection() throws IOException {
-        new Requester(root).method("DELETE").withPreview(LOKI).to(protection_url);
+        new Requester(root).method("DELETE").to(protection_url);
     }
 
     /**

src/main/java/org/kohsuke/github/GHBranchProtection.java

@@ -3,14 +3,21 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
+import static org.kohsuke.github.Previews.ZZZAX;
+
+import java.io.IOException;
 import java.util.Collection;
 
 @SuppressFBWarnings(value = { "UWF_UNWRITTEN_PUBLIC_OR_PROTECTED_FIELD", "UWF_UNWRITTEN_FIELD", "NP_UNWRITTEN_FIELD",
 		"URF_UNREAD_FIELD" }, justification = "JSON API")
 public class GHBranchProtection {
+    private static final String REQUIRE_SIGNATURES_URI = "/required_signatures";
+
 	@JsonProperty("enforce_admins")
 	private EnforceAdmins enforceAdmins;
 
+	private GitHub root;
+
 	@JsonProperty("required_pull_request_reviews")
 	private RequiredReviews requiredReviews;
 
@@ -23,6 +30,18 @@ public class GHBranchProtection {
 	@JsonProperty
 	private String url;
 
+	@Preview @Deprecated
+    public RequiredSignatures enabledSignedCommits() throws IOException {
+        return requester().method("POST")
+                .to(url + REQUIRE_SIGNATURES_URI, RequiredSignatures.class);
+    }
+
+	@Preview @Deprecated
+    public void disableSignedCommits() throws IOException {
+        requester().method("DELETE")
+                .to(url + REQUIRE_SIGNATURES_URI);
+    }
+
 	public EnforceAdmins getEnforceAdmins() {
         return enforceAdmins;
     }
@@ -31,6 +50,12 @@ public RequiredReviews getRequiredReviews() {
         return requiredReviews;
     }
 
+    @Preview @Deprecated
+    public RequiredSignatures getRequiredSignatures() throws IOException {
+        return requester().method("GET")
+                .to(url + REQUIRE_SIGNATURES_URI, RequiredSignatures.class);
+    }
+
     public RequiredStatusChecks getRequiredStatusChecks() {
         return requiredStatusChecks;
     }
@@ -43,6 +68,15 @@ public String getUrl() {
         return url;
     }
 
+    GHBranchProtection wrap(GHBranch branch) {
+        this.root = branch.getRoot();
+        return this;
+    }
+
+    private Requester requester() {
+        return new Requester(root).withPreview(ZZZAX);
+    }
+
     public static class EnforceAdmins {
 		@JsonProperty
 		private boolean enabled;
@@ -69,6 +103,9 @@ public static class RequiredReviews {
 		@JsonProperty("require_code_owner_reviews")
 		private boolean requireCodeOwnerReviews;
 
+		@JsonProperty("required_approving_review_count")
+		private int requiredReviewers;
+
 		@JsonProperty
 		private String url;
 
@@ -87,6 +124,27 @@ public boolean isDismissStaleReviews() {
         public boolean isRequireCodeOwnerReviews() {
             return requireCodeOwnerReviews;
         }
+
+        public int getRequiredReviewers()
+        {
+            return requiredReviewers;
+        }
+	}
+
+	public static class RequiredSignatures {
+	    @JsonProperty
+        private boolean enabled;
+
+        @JsonProperty
+        private String url;
+
+        public String getUrl() {
+            return url;
+        }
+
+        public boolean isEnabled() {
+            return enabled;
+        }
 	}
 
 	public static class RequiredStatusChecks {

src/main/java/org/kohsuke/github/GHBranchProtectionBuilder.java

@@ -44,7 +44,12 @@ public GHBranchProtectionBuilder addRequiredChecks(String... checks) {
     }
 
     public GHBranchProtectionBuilder dismissStaleReviews() {
-        getPrReviews().put("dismiss_stale_reviews", true);
+        dismissStaleReviews(true);
+        return this;
+    }
+
+    public GHBranchProtectionBuilder dismissStaleReviews(boolean v) {
+        getPrReviews().put("dismiss_stale_reviews", v);
         return this;
     }
 
@@ -54,7 +59,8 @@ public GHBranchProtection enable() throws IOException {
                 .withNullable("required_pull_request_reviews", prReviews)
                 .withNullable("restrictions", restrictions)
                 .withNullable("enforce_admins", enforceAdmins)
-                .to(branch.getProtectionUrl().toString(), GHBranchProtection.class);
+                .to(branch.getProtectionUrl().toString(), GHBranchProtection.class)
+                .wrap(branch);
     }
 
     public GHBranchProtectionBuilder includeAdmins() {
@@ -66,6 +72,11 @@ public GHBranchProtectionBuilder includeAdmins(boolean v) {
         return this;
     }
 
+    public GHBranchProtectionBuilder requiredReviewers(int v) {
+        getPrReviews().put("required_approving_review_count", v);
+        return this;
+    }
+
     public GHBranchProtectionBuilder requireBranchIsUpToDate() {
         return requireBranchIsUpToDate(true);
     }
@@ -89,6 +100,16 @@ public GHBranchProtectionBuilder requireReviews() {
         return this;
     }
 
+    public GHBranchProtectionBuilder restrictReviewDismissals() {
+        getPrReviews();
+
+        if (!prReviews.containsKey("dismissal_restrictions")) {
+            prReviews.put("dismissal_restrictions", new Restrictions());
+        }
+
+        return this;
+    }
+
     public GHBranchProtectionBuilder restrictPushAccess() {
         getRestrictions();
         return this;
@@ -151,12 +172,7 @@ public GHBranchProtectionBuilder userReviewDismissals(GHUser... users) {
     }
 
     private void addReviewRestriction(String restriction, boolean isTeam) {
-        getPrReviews();
-
-        if (!prReviews.containsKey("dismissal_restrictions")) {
-            prReviews.put("dismissal_restrictions", new Restrictions());
-        }
-
+        restrictReviewDismissals();
         Restrictions restrictions = (Restrictions) prReviews.get("dismissal_restrictions");
 
         if (isTeam) {
@@ -188,7 +204,7 @@ private StatusChecks getStatusChecks() {
     }
 
     private Requester requester() {
-        return new Requester(branch.getRoot()).withPreview(LOKI);
+        return new Requester(branch.getRoot()).withPreview(LUKE_CAGE);
     }
 
     private static class Restrictions {

src/main/java/org/kohsuke/github/Previews.java

@@ -5,7 +5,9 @@
  */
 /*package*/ class Previews {
     static final String LOKI = "application/vnd.github.loki-preview+json";
+    static final String LUKE_CAGE = "application/vnd.github.luke-cage-preview+json";
     static final String DRAX = "application/vnd.github.drax-preview+json";
     static final String SQUIRREL_GIRL = "application/vnd.github.squirrel-girl-preview";
     static final String CLOAK = "application/vnd.github.cloak-preview";
+    static final String ZZZAX = "application/vnd.github.zzzax-preview+json";
 }

src/test/java/org/kohsuke/github/GHBranchProtectionTest.java

@@ -4,6 +4,7 @@
 import org.junit.Test;
 import org.kohsuke.github.GHBranchProtection.EnforceAdmins;
 import org.kohsuke.github.GHBranchProtection.RequiredReviews;
+import org.kohsuke.github.GHBranchProtection.RequiredSignatures;
 import org.kohsuke.github.GHBranchProtection.RequiredStatusChecks;
 
 import java.io.FileNotFoundException;
@@ -32,6 +33,12 @@ public void setUp() throws Exception {
         branch = repo.getBranch(BRANCH);
 
         if (branch.isProtected()) {
+            GHBranchProtection protection = branch.getProtection();
+            if (protection.getRequiredSignatures().isEnabled()) {
+                protection.disableSignedCommits();
+            }
+
+            assertFalse(protection.getRequiredSignatures().isEnabled());
             branch.disableProtection();
         }
 
@@ -47,6 +54,7 @@ public void testEnableBranchProtections() throws Exception {
                 .requireBranchIsUpToDate()
                 .requireCodeOwnReviews()
                 .dismissStaleReviews()
+                .requiredReviewers(2)
                 .includeAdmins()
                 .enable();
 
@@ -59,6 +67,7 @@ public void testEnableBranchProtections() throws Exception {
         assertNotNull(requiredReviews);
         assertTrue(requiredReviews.isDismissStaleReviews());
         assertTrue(requiredReviews.isRequireCodeOwnerReviews());
+        assertEquals(2, requiredReviews.getRequiredReviewers());
 
         EnforceAdmins enforceAdmins = protection.getEnforceAdmins();
         assertNotNull(enforceAdmins);
@@ -79,4 +88,22 @@ public void testEnableRequireReviewsOnly() throws Exception {
 
        assertNotNull(protection.getRequiredReviews());
     }
+
+    @Test
+    public void testSignedCommits() throws Exception {
+        GHBranchProtection protection = branch.enableProtection().enable();
+
+        RequiredSignatures signatures = protection.getRequiredSignatures();
+        assertNotNull(signatures);
+        assertFalse(signatures.isEnabled());
+
+        signatures = protection.enabledSignedCommits();
+        assertNotNull(signatures);
+        assertTrue(signatures.isEnabled());
+
+        protection.disableSignedCommits();
+        signatures = protection.getRequiredSignatures();
+        assertNotNull(signatures);
+        assertFalse(signatures.isEnabled());
+    }
 }