new file mode 100644
--- /dev/null
+++ b/tests/test_externals.py
@@ -0,0 +1,87 @@
+import cStringIO
+import os
+import shutil
+import sys
+import tempfile
+import unittest
+
+from mercurial import hg
+from mercurial import ui
+from mercurial import node
+
+import fetch_command
+import svnexternals
+import test_util
+
+
+class TestFetchExternals(test_util.TestBase):
+    def test_externalsfile(self):
+        f = svnexternals.externalsfile()
+        f['t1'] = 'dir1 -r10 svn://foobar'
+        f['t 2'] = 'dir2 -r10 svn://foobar'
+        f['t3'] = ['dir31 -r10 svn://foobar', 'dir32 -r10 svn://foobar']
+        
+        refext = """\
+[t 2]
+ dir2 -r10 svn://foobar
+[t1]
+ dir1 -r10 svn://foobar
+[t3]
+ dir31 -r10 svn://foobar
+ dir32 -r10 svn://foobar
+"""
+        value = f.write()
+        self.assertEqual(refext, value)
+
+        f2 = svnexternals.externalsfile()
+        f2.read(value)
+        self.assertEqual(sorted(f), sorted(f2))
+        for t in f:
+            self.assertEqual(f[t], f2[t])
+
+    def test_externals(self, stupid=False):
+        repo = self._load_fixture_and_fetch('externals.svndump', stupid=stupid)
+
+        ref0 = """\
+[.]
+ ../externals/project1 deps/project1
+"""
+        self.assertEqual(ref0, repo[0]['.hgsvnexternals'].data())
+        ref1 = """\
+[.]
+ ../externals/project1 deps/project1
+ ../externals/project2 deps/project2
+"""
+        self.assertEqual(ref1, repo[1]['.hgsvnexternals'].data())
+
+        ref2 = """\
+[.]
+ ../externals/project2 deps/project2
+[subdir]
+ ../externals/project1 deps/project1
+[subdir2]
+ ../externals/project1 deps/project1
+"""
+        self.assertEqual(ref2, repo[2]['.hgsvnexternals'].data())
+
+        ref3 = """\
+[.]
+ ../externals/project2 deps/project2
+[subdir2]
+ ../externals/project1 deps/project1
+"""
+        self.assertEqual(ref3, repo[3]['.hgsvnexternals'].data())
+
+        ref4 = """\
+[.]
+ ../externals/project2 deps/project2
+"""
+        self.assertEqual(ref4, repo[4]['.hgsvnexternals'].data())
+
+    def test_externals_stupid(self):
+        self.test_externals(True)
+
+def suite():
+    all = [unittest.TestLoader().loadTestsFromTestCase(TestFetchExternals),
+          ]
+    return unittest.TestSuite(all)