diff --git a/pom.xml b/pom.xml
index 929f227..8f3a377 100644
--- a/pom.xml
+++ b/pom.xml
@@ -22,6 +22,7 @@
         <junit.version>5.2.0</junit.version>
         <assertj.version>3.10.0</assertj.version>
         <mon.version>0.4.0</mon.version>
+        <mockito.version>2.18.3</mockito.version>
     </properties>
 
     <dependencies>
@@ -59,6 +60,12 @@
             <artifactId>junit-jupiter-engine</artifactId>
             <scope>runtime</scope>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>${mockito.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <dependencyManagement>
diff --git a/src/main/java/net/kemitix/gitdb/GitDB.java b/src/main/java/net/kemitix/gitdb/GitDB.java
index 201f326..25d5302 100644
--- a/src/main/java/net/kemitix/gitdb/GitDB.java
+++ b/src/main/java/net/kemitix/gitdb/GitDB.java
@@ -22,9 +22,8 @@
 package net.kemitix.gitdb;
 
 import org.eclipse.jgit.api.Git;
-import org.eclipse.jgit.api.InitCommand;
-import org.eclipse.jgit.api.errors.GitAPIException;
 
+import java.nio.file.NotDirectoryException;
 import java.nio.file.Path;
 
 /**
@@ -39,12 +38,10 @@ public interface GitDB {
      *
      * @param dbDir the path to initialise the local repo in
      * @return a GitDB instance for the created local gitdb
-     * @throws GitAPIException if there is an error initialising the Git repo
+     * @throws NotDirectoryException if {@code dbDir} it is not a directory
      */
-    static GitDB initLocal(final Path dbDir) throws GitAPIException {
-        final InitCommand initCommand = Git.init().setGitDir(dbDir.toFile()).setBare(true);
-        final Git git = initCommand.call();
-        return new GitDBLocal(git);
+    static GitDB initLocal(final Path dbDir) throws NotDirectoryException {
+        return new GitDBLocal(Git.init(), dbDir.toFile());
     }
 
 }
diff --git a/src/main/java/net/kemitix/gitdb/GitDBLocal.java b/src/main/java/net/kemitix/gitdb/GitDBLocal.java
index df29913..290bccd 100644
--- a/src/main/java/net/kemitix/gitdb/GitDBLocal.java
+++ b/src/main/java/net/kemitix/gitdb/GitDBLocal.java
@@ -21,19 +21,42 @@
 
 package net.kemitix.gitdb;
 
-import lombok.RequiredArgsConstructor;
 import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.InitCommand;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.api.errors.JGitInternalException;
+
+import java.io.File;
+import java.nio.file.NotDirectoryException;
 
 /**
  * Implementation of GitDB for working with a local Repo.
  *
  * @author Paul Campbell (pcampbell@kemitix.net)
  */
-@RequiredArgsConstructor
+
 class GitDBLocal implements GitDB {
 
     private final Git git;
 
+    /**
+     * Constructors a new instance of this class.
+     *
+     * @param initCommand a JGit InitCommand
+     * @param dbDir       the path to instantiate the git repo in
+     * @throws NotDirectoryException if {@code dbDir} it is not a directory
+     */
+    @SuppressWarnings("avoidhidingcauseexception")
+    GitDBLocal(final InitCommand initCommand, final File dbDir) throws NotDirectoryException {
+        try {
+            this.git = initCommand.setGitDir(dbDir).setBare(true).call();
+        } catch (JGitInternalException e) {
+            throw new NotDirectoryException(dbDir.toString());
+        } catch (GitAPIException e) {
+            throw new UnexpectedGitDbException("Unhandled Git API Exception", e);
+        }
+    }
+
     //    @Override
     //    @SneakyThrows
     //    public <T> T get(Branch branch, Key key, Class<T> type) {
diff --git a/src/main/java/net/kemitix/gitdb/UnexpectedGitDbException.java b/src/main/java/net/kemitix/gitdb/UnexpectedGitDbException.java
new file mode 100644
index 0000000..a6a32d8
--- /dev/null
+++ b/src/main/java/net/kemitix/gitdb/UnexpectedGitDbException.java
@@ -0,0 +1,45 @@
+/*
+  The MIT License (MIT)
+
+  Copyright (c) 2018 Paul Campbell
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+  and associated documentation files (the "Software"), to deal in the Software without restriction,
+  including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+  and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so,
+  subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in all copies
+  or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
+  AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package net.kemitix.gitdb;
+
+/**
+ * Unchecked exception thrown when JGit throws a an unexpected exception.
+ *
+ * @author Paul Campbell (pcampbell@kemitix.net)
+ */
+public class UnexpectedGitDbException extends RuntimeException {
+
+    /**
+     * Constructs an instance of this class.
+     *
+     * @param message the detail message. The detail message is saved for
+     *                later retrieval by the {@link #getMessage()} method.
+     * @param cause   the cause (which is saved for later retrieval by the
+     *                {@link #getCause()} method).  (A <tt>null</tt> value is
+     *                permitted, and indicates that the cause is nonexistent or
+     *                unknown.)
+     */
+    public UnexpectedGitDbException(final String message, final Throwable cause) {
+        super(message, cause);
+    }
+
+}
diff --git a/src/test/java/net/kemitix/gitdb/GitDBTest.java b/src/test/java/net/kemitix/gitdb/GitDBTest.java
index f391bf7..325c812 100644
--- a/src/test/java/net/kemitix/gitdb/GitDBTest.java
+++ b/src/test/java/net/kemitix/gitdb/GitDBTest.java
@@ -1,17 +1,24 @@
 package net.kemitix.gitdb;
 
+import org.assertj.core.api.WithAssertions;
+import org.eclipse.jgit.api.InitCommand;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.mockito.junit.jupiter.MockitoSettings;
+import org.mockito.quality.Strictness;
 
 import java.io.IOException;
-import java.nio.file.DirectoryStream;
-import java.nio.file.Files;
-import java.nio.file.Path;
+import java.nio.file.*;
 import java.util.List;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.*;
 
-class GitDBTest {
+@ExtendWith(MockitoExtension.class)
+class GitDBTest implements WithAssertions {
 
 //    private final Branch master = Branch.name("master");
 //    private final Message message = Message.message(UUID.randomUUID().toString());
@@ -20,13 +27,13 @@ class GitDBTest {
 
     // When initialising a repo in a dir that doesn't exist then a bare repo is created
     @Test
-    void initRepo_whenDirNotExist_thenCreateBareRepo() throws IOException, GitAPIException {
+    void initRepo_whenDirNotExist_thenCreateBareRepo() throws IOException {
         //given
         final Path dir = dirDoesNotExist();
         //when
-        final GitDB gitdb = GitDB.initLocal(dir);
+        final GitDB gitDB = GitDB.initLocal(dir);
         //then
-        assertThat(gitdb).isNotNull();
+        assertThat(gitDB).isNotNull();
         assertThatIsBareRepo(dir);
     }
 
@@ -52,19 +59,43 @@ class GitDBTest {
         return directory;
     }
 
+    // When initialising a repo and an unexpected error occurs then an exception is thrown
+    @Test
+    void initRepo_whenUnexpectedError_thenThrowException() throws IOException, GitAPIException {
+        //given
+        final Path dbDir = dirDoesNotExist();
+        final InitCommand initCommand = spy(InitCommand.class);
+        given(initCommand.call()).willThrow(mock(GitAPIException.class));
+        //then
+        assertThatExceptionOfType(UnexpectedGitDbException.class)
+                .isThrownBy(() -> new GitDBLocal(initCommand, dbDir.toFile()))
+                .withMessageContaining("Unhandled Git API Exception");
+    }
+
     // When initialising a repo in a dir that is a file then an exception is thrown
     @Test
-    void initRepo_whenDirIsFile_thenThrowException() {
+    void initRepo_whenDirIsFile_thenThrowException() throws IOException {
+        //given
+        final Path dir = fileExists();
+        //then
+        assertThatExceptionOfType(NotDirectoryException.class)
+                .isThrownBy(() -> GitDB.initLocal(dir))
+                .withMessageContaining(dir.toString());
+    }
+
+    private Path fileExists() throws IOException {
+        return Files.createTempFile("gitdb", "file");
     }
 
     // When initialising a repo in a dir is exists then an exception is thrown
-    @Test
-    void initRepo_whenDirExists_thenThrowException() {
-    }
+    //@Test
+    //void initRepo_whenDirExists_thenThrowException() {
+    //}
 
-    // When opening a repo in a dir that doesn't exist then an exception is thrown
-    // When opening a repo in a dir that is a file then an exception is thrown
     // When opening a repo in a dir that is not a bare repo then an exception is thrown
+    // When opening a repo in a dir that is a file then an exception is thrown
+    // When opening a repo in a dir that doesn't exist then an exception is thrown
+
     // When opening a repo in a dir that is a bare repo then GitDb is returned
 
     // Given a valid GitDb handle