Prevent repo.Lookup() to accept GitLink as a target type

nulltoken · nulltoken · commit 023eaf4ff434 · 2013-04-29T19:27:05.000+02:00
diff --git a/LibGit2Sharp.Tests/RepositoryFixture.cs b/LibGit2Sharp.Tests/RepositoryFixture.cs
@@ -412,6 +412,15 @@ public void LookingUpWithATooShortShaThrows()
             }
         }
 
+        [Fact]
+        public void LookingUpAGitLinkThrows()
+        {
+            using (var repo = new Repository(BareTestRepoPath))
+            {
+                Assert.Throws<ArgumentException>(() => repo.Lookup<GitLink>("e90810b"));
+            }
+        }
+
         [Fact]
         public void CanDiscoverABareRepoGivenTheRepoPath()
         {
diff --git a/LibGit2Sharp/RepositoryExtensions.cs b/LibGit2Sharp/RepositoryExtensions.cs
@@ -21,6 +21,8 @@ public static class RepositoryExtensions
         /// <returns></returns>
         public static T Lookup<T>(this IRepository repository, string objectish) where T : GitObject
         {
+            EnsureNoGitLink<T>();
+
             return (T)repository.Lookup(objectish, GitObject.TypeToTypeMap[typeof (T)]);
         }
 
@@ -33,9 +35,21 @@ public static T Lookup<T>(this IRepository repository, string objectish) where T
         /// <returns></returns>
         public static T Lookup<T>(this IRepository repository, ObjectId id) where T : GitObject
         {
+            EnsureNoGitLink<T>();
+
             return (T)repository.Lookup(id, GitObject.TypeToTypeMap[typeof(T)]);
         }
 
+        private static void EnsureNoGitLink<T>() where T : GitObject
+        {
+            if (typeof(T) != typeof(GitLink))
+            {
+                return;
+            }
+
+            throw new ArgumentException("A GitObject of type 'GitLink' cannot be looked up.");
+        }
+
         /// <summary>
         ///   Creates a lightweight tag with the specified name. This tag will point at the commit pointed at by the <see cref = "Repository.Head" />.
         /// </summary>

Original file line number	Diff line number	Diff line change
`@@ -412,6 +412,15 @@ public void LookingUpWithATooShortShaThrows()`
`412`	`412`	`}`
`413`	`413`	`}`
`414`	`414`
	`415`	`+ [Fact]`
	`416`	`+ public void LookingUpAGitLinkThrows()`
	`417`	`+ {`
	`418`	`+ using (var repo = new Repository(BareTestRepoPath))`
	`419`	`+ {`
	`420`	`+ Assert.Throws<ArgumentException>(() => repo.Lookup<GitLink>("e90810b"));`
	`421`	`+ }`
	`422`	`+ }`
	`423`	`+`
`415`	`424`	`[Fact]`
`416`	`425`	`public void CanDiscoverABareRepoGivenTheRepoPath()`
`417`	`426`	`{`