Add edit-constraints command.

This allows shell editing of a constraints file, which we need to do
in devstack when installing a constrained library from git.

Change-Id: Ibdbfc786b5d2f56d2e41d329c8766bef7b2e6854

openstack_requirements/cmds/edit_constraint.py

@@ -0,0 +1,73 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import optparse
+import os.path
+import sys
+import textwrap
+
+
+from openstack_requirements import requirement
+
+
+def edit(reqs, name, replacement):
+    if not replacement:
+        reqs.pop(name, None)
+    else:
+        reqs[name] = [(requirement.Requirement('', '', '', replacement), '')]
+    result = []
+    for entries in reqs.values():
+        for entry, _ in entries:
+            result.append(entry)
+    return requirement.Requirements(sorted(result))
+
+
+# -- untested UI glue from here down.
+
+
+def _validate_options(options, args):
+    """Check that options and arguments are valid.
+
+    :param options: The optparse options for this program.
+    :param args: The args for this program.
+    """
+    if len(args) < 2:
+        raise Exception("No enough arguments given")
+    if not os.path.exists(args[0]):
+        raise Exception(
+            "Constraints file %(con)s not found."
+            % dict(con=args[0]))
+
+
+def main(argv=None, stdout=None):
+    parser = optparse.OptionParser(
+        usage="%prog [options] constraintpath name replacement",
+        epilog=textwrap.dedent("""\
+            Replaces any entries of "name" in the constraints file with
+            "replacement". If "name" is not present, it is added to the end of
+            the file. If "replacement" is missing or empty, remove "name" from
+            the file.
+            """))
+    options, args = parser.parse_args(argv)
+    if stdout is None:
+        stdout = sys.stdout
+    _validate_options(options, args)
+    args = args + [""]
+    content = open(args[0], 'rt').read()
+    reqs = requirement.parse(content)
+    out_reqs = edit(reqs, args[1], args[2])
+    out = requirement.to_content(out_reqs, prefix=False)
+    with open(args[0] + '.tmp', 'wt') as f:
+        f.write(out)
+    os.rename(args[0] + '.tmp', args[0])
+    return 0

openstack_requirements/tests/test_edit_constraint.py

@@ -0,0 +1,65 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import io
+import os
+
+import fixtures
+import testscenarios
+import testtools
+
+from openstack_requirements.cmds import edit_constraint as edit
+from openstack_requirements import requirement
+
+
+load_tests = testscenarios.load_tests_apply_scenarios
+
+
+class SmokeTest(testtools.TestCase):
+
+    def test_make_url(self):
+        stdout = io.StringIO()
+        tmpdir = self.useFixture(fixtures.TempDir()).path
+        constraints_path = os.path.join(tmpdir, 'name.txt')
+        with open(constraints_path, 'wt') as f:
+            f.write('bar===1\nfoo===1.0.2\nquux==3\n')
+        rv = edit.main(
+            [constraints_path, 'foo', '--', '-e /path/to/foo'], stdout)
+        self.assertEqual(0, rv)
+        content = open(constraints_path, 'rt').read()
+        self.assertEqual('-e /path/to/foo\nbar===1\nquux==3\n', content)
+
+
+class TestEdit(testtools.TestCase):
+
+    def test_add(self):
+        reqs = {}
+        res = edit.edit(reqs, 'foo', 'foo==1.2')
+        self.assertEqual(requirement.Requirements(
+            [requirement.Requirement('', '', '', 'foo==1.2')]), res)
+
+    def test_delete(self):
+        reqs = requirement.parse('foo==1.2\n')
+        res = edit.edit(reqs, 'foo', '')
+        self.assertEqual(requirement.Requirements([]), res)
+
+    def test_replace(self):
+        reqs = requirement.parse('foo==1.2\n')
+        res = edit.edit(reqs, 'foo', 'foo==1.3')
+        self.assertEqual(requirement.Requirements(
+            [requirement.Requirement('', '', '', 'foo==1.3')]), res)
+
+    def test_replace_many(self):
+        reqs = requirement.parse('foo==1.2;p\nfoo==1.3;q')
+        res = edit.edit(reqs, 'foo', 'foo==1.3')
+        self.assertEqual(requirement.Requirements(
+            [requirement.Requirement('', '', '', 'foo==1.3')]), res)

setup.cfg

@@ -23,5 +23,6 @@ packages =
 
 [entry_points]
 console_scripts =
+    edit-constraints = openstack_requirements.cmds.edit_constraint:main
     generate-constraints = openstack_requirements.cmds.generate:main
     update-requirements = openstack_requirements.cmds.update:main