Add TreeDefinition.Remove()

2 files changed, 85 insertions, 0 deletions

diff --git a/LibGit2Sharp.Tests/ObjectDatabaseFixture.cs b/LibGit2Sharp.Tests/ObjectDatabaseFixture.cs
index fbece8f0..b5e1735c 100644
--- a/LibGit2Sharp.Tests/ObjectDatabaseFixture.cs
+++ b/LibGit2Sharp.Tests/ObjectDatabaseFixture.cs
@@ -69,6 +69,51 @@ namespace LibGit2Sharp.Tests
         }
 
         [Fact]
+        public void CanCreateATreeByRemovingEntriesFromExistingOne()
+        {
+            TemporaryCloneOfTestRepo scd = BuildTemporaryCloneOfTestRepo();
+
+            using (var repo = new Repository(scd.RepositoryPath))
+            {
+                TreeDefinition td = TreeDefinition.From(repo.Head.Tip.Tree)
+                    .Remove("branch_file.txt")
+                    .Remove("1/branch_file.txt");
+
+                Tree tree = repo.ObjectDatabase.CreateTree(td);
+                Assert.NotNull(tree);
+
+                Assert.Null(tree["branch_file.txt"]);
+                Assert.Null(tree["1/branch_file.txt"]);
+                Assert.Null(tree["1"]);
+
+                Assert.Equal("814889a078c031f61ed08ab5fa863aea9314344d", tree.Sha);
+            }
+        }
+
+        [Fact]
+        public void RemovingANonExistingEntryFromATreeDefinitionHasNoSideEffect()
+        {
+            TemporaryCloneOfTestRepo scd = BuildTemporaryCloneOfTestRepo();
+
+            using (var repo = new Repository(scd.RepositoryPath))
+            {
+                Tree head = repo.Head.Tip.Tree;
+
+                TreeDefinition td = TreeDefinition.From(head)
+                    .Remove("123")
+                    .Remove("nope")
+                    .Remove("not/here")
+                    .Remove("neither/in/here")
+                    .Remove("README/is/a-Blob/not-a-Tree");
+
+                Tree tree = repo.ObjectDatabase.CreateTree(td);
+                Assert.NotNull(tree);
+
+                tree.ShouldEqual(head);
+            }
+        }
+
+        [Fact]
         public void CanCreateAnEmptyTree()
         {
             TemporaryCloneOfTestRepo scd = BuildTemporaryCloneOfTestRepo();
diff --git a/LibGit2Sharp/TreeDefinition.cs b/LibGit2Sharp/TreeDefinition.cs
index 8ebe90e7..e781ab11 100644
--- a/LibGit2Sharp/TreeDefinition.cs
+++ b/LibGit2Sharp/TreeDefinition.cs
@@ -46,6 +46,46 @@ namespace LibGit2Sharp
         }
 
         /// <summary>
+        ///   Removes a <see cref="TreeEntryDefinition"/> located the specified <paramref name="treeEntryPath"/> path.
+        /// </summary>
+        /// <param name="treeEntryPath">The path within this <see cref="TreeDefinition"/>.</param>
+        /// <returns>The current <see cref="TreeDefinition"/>.</returns>
+        public TreeDefinition Remove(string treeEntryPath)
+        {
+            Ensure.ArgumentNotNullOrEmptyString(treeEntryPath, "treeEntryPath");
+
+            if (this[treeEntryPath] == null)
+            {
+                return this;
+            }
+
+            Tuple<string, string> segments = ExtractPosixLeadingSegment(treeEntryPath);
+
+            if (segments.Item2 == null)
+            {
+                entries.Remove(segments.Item1);
+            }
+
+            if (!unwrappedTrees.ContainsKey(segments.Item1))
+            {
+                return this;
+            }
+
+            if (segments.Item2 != null)
+            {
+                unwrappedTrees[segments.Item1].Remove(segments.Item2);
+            }
+
+            if (unwrappedTrees[segments.Item1].entries.Count == 0)
+            {
+                unwrappedTrees.Remove(segments.Item1);
+                entries.Remove(segments.Item1);
+            }
+
+            return this;
+        }
+
+        /// <summary>
         ///   Adds or replaces a <see cref="TreeEntryDefinition"/> at the specified <paramref name="targetTreeEntryPath"/> location.
         /// </summary>
         /// <param name="targetTreeEntryPath">The path within this <see cref="TreeDefinition"/>.</param>