Add test for clone depth

Adds test for the use of a clone depth of 1 for cases where no refspec
is used. This relies on an external source (an existing test
repository), so may break easier.

tests/test_clone_depth.py

@@ -0,0 +1,105 @@
+"""
+Test that a clone depth of 1 is used and good enough when no refspec is used
+
+Note: the tests don't actually run the container. Building the
+container requires a specific repository and commit to be checked out,
+and that is the only thing that is tested.
+
+"""
+import subprocess
+import requests
+import time
+from repo2docker.app import Repo2Docker
+
+
+URL = "https://github.com/binderhub-ci-repos/repo2docker-ci-clone-depth"
+
+
+def test_clone_depth():
+    """Test a remote repository, without a refspec"""
+
+    app = Repo2Docker()
+    argv = [URL]
+    app.initialize(argv)
+    app.debug = True
+    app.run = False
+    app.cleanup_checkout = False
+    app.start()  # This just build the image and does not run it.
+
+    # Building the image has already put us in the cloned repository directory
+    cmd = ['git', 'rev-parse', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'703322e9c6635ba1835d3b92eafbabeca0042c3e'
+    cmd = ['git', 'rev-list', '--count', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'1'
+    with open('COMMIT') as fp:
+        assert fp.read() == '100\n'
+
+
+def test_clone_depth_full():
+    """Test a remote repository, with a refspec of 'master'"""
+
+    app = Repo2Docker()
+    argv = ['--ref', 'master', URL]
+    app.initialize(argv)
+    app.debug = True
+    app.run = False
+    app.cleanup_checkout = False
+    app.start()  # This just build the image and does not run it.
+
+    # Building the image has already put us in the cloned repository directory
+    cmd = ['git', 'rev-parse', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'703322e9c6635ba1835d3b92eafbabeca0042c3e'
+    cmd = ['git', 'rev-list', '--count', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'100'
+    with open('COMMIT') as fp:
+        assert fp.read() == '100\n'
+
+
+def test_clone_depth_full2():
+    """Test a remote repository, with a refspec of the master commit hash"""
+
+    app = Repo2Docker()
+    argv = ['--ref', '703322e', URL]
+
+    app.initialize(argv)
+    app.debug = True
+    app.run = False
+    app.cleanup_checkout = False
+    app.start()  # This just build the image and does not run it.
+
+    # Building the image has already put us in the cloned repository directory
+    cmd = ['git', 'rev-parse', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'703322e9c6635ba1835d3b92eafbabeca0042c3e'
+    cmd = ['git', 'rev-list', '--count', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'100'
+    with open('COMMIT') as fp:
+        assert fp.read() == '100\n'
+
+
+def test_clone_depth_mid():
+    """Test a remote repository, with a refspec of a commit hash halfway"""
+
+    app = Repo2Docker()
+    argv = ['--ref', '8bc4f21', URL]
+
+    app.initialize(argv)
+    app.debug = True
+    app.run = False
+    app.cleanup_checkout = False
+    app.start()  # This just build the image and does not run it.
+
+    # Building the image has already put us in the cloned repository directory
+    cmd = ['git', 'rev-parse', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'8bc4f216856f86f6fc25a788b744b93b87e9ba48'
+    cmd = ['git', 'rev-list', '--count', 'HEAD']
+    p = subprocess.run(cmd, stdout=subprocess.PIPE)
+    assert p.stdout.strip() == b'50'
+    with open('COMMIT') as fp:
+        assert fp.read() == '50\n'