[ADD] forwardport: tests that fw batches can vary

This tests that the new setup *does* allow both removing PRs from a
forward-ported batch (something which may have worked previously
already, anyway) and importantly *adding* PRs to a forward ported
batch.

The updated batch behaves somewhat like a new batch, but it should
retain the history via linking through the batch, and it allows
cross-repo fixes which were not necessary earlier (e.g. because we're
touching an API of repo A which was not used in repo B in earlier
branches, but now is), something which was not really possible before
the refactoring of batches & co.

forwardport/tests/test_batches.py

@@ -1,4 +1,4 @@
-from utils import Commit, make_basic
+from utils import Commit, make_basic, to_pr
 
 
 def test_single_updated(env, config, make_repo):
@@ -87,3 +87,127 @@ def test_single_updated(env, config, make_repo):
 
     assert pr22_id.source_id == pr2_id
     assert pr22_id.parent_id == pr21_id
+
+def test_closing_during_fp(env, config, make_repo, users):
+    """ Closing a PR after it's been ported once should not port it further, but
+    the rest of the batch should carry on
+    """
+    r1, _ = make_basic(env, config, make_repo)
+    r2, _ = make_basic(env, config, make_repo)
+    env['runbot_merge.repository'].search([]).required_statuses = 'default'
+
+    with r1, r2:
+        r1.make_commits('a', Commit('1', tree={'1': '0'}), ref='heads/aref')
+        pr1 = r1.make_pr(target='a', head='aref')
+        r1.post_status('aref', 'success')
+        pr1.post_comment('hansen r+', config['role_reviewer']['token'])
+
+        r2.make_commits('a', Commit('2', tree={'2': '0'}), ref='heads/aref')
+        pr2 = r2.make_pr(target='a', head='aref')
+        r2.post_status('aref', 'success')
+        pr2.post_comment('hansen r+', config['role_reviewer']['token'])
+    env.run_crons()
+
+    with r1, r2:
+        r1.post_status('staging.a', 'success')
+        r2.post_status('staging.a', 'success')
+    env.run_crons()
+
+    pr1_id = to_pr(env, pr1)
+    [pr1_1_id] = pr1_id.forwardport_ids
+    pr2_id = to_pr(env, pr2)
+    [pr2_1_id] = pr2_id.forwardport_ids
+
+    with r1:
+        r1.get_pr(pr1_1_id.number).close(config['role_user']['token'])
+
+    with r2:
+        r2.post_status(pr2_1_id.head, 'success')
+    env.run_crons()
+
+    assert env['runbot_merge.pull_requests'].search_count([]) == 5,\
+        "only one of the forward ports should be ported"
+    assert not env['runbot_merge.pull_requests'].search([('parent_id', '=', pr1_1_id.id)]),\
+        "the closed PR should not be ported"
+
+def test_add_pr_during_fp(env, config, make_repo, users):
+    """ It should be possible to add new PRs to an FP batch
+    """
+    r1, _ = make_basic(env, config, make_repo)
+    r2, fork2 = make_basic(env, config, make_repo)
+    repos = env['runbot_merge.repository'].search([])
+    repos.required_statuses = 'default'
+    # needs a "d" branch
+    repos[0].project_id.write({
+        'branch_ids': [(0, 0, {'name': 'd', 'sequence': 40})],
+    })
+    with r1, r2:
+        r1.make_ref("heads/d", r1.commit("c").id)
+        r2.make_ref("heads/d", r2.commit("c").id)
+
+    with r1, r2:
+        r1.make_commits('a', Commit('1', tree={'1': '0'}), ref='heads/aref')
+        pr1_a = r1.make_pr(target='a', head='aref')
+        r1.post_status('aref', 'success')
+        pr1_a.post_comment('hansen r+', config['role_reviewer']['token'])
+    env.run_crons()
+
+    with r1, r2:
+        r1.post_status('staging.a', 'success')
+        r2.post_status('staging.a', 'success')
+    env.run_crons()
+
+    pr1_a_id = to_pr(env, pr1_a)
+    [pr1_b_id] = pr1_a_id.forwardport_ids
+
+    with r2, fork2:
+        fork2.make_commits('b', Commit('2', tree={'2': '0'}), ref=f'heads/{pr1_b_id.refname}')
+        pr2_b = r2.make_pr(title="B", target='b', head=f'{fork2.owner}:{pr1_b_id.refname}')
+    env.run_crons()
+
+    pr2_b_id = to_pr(env, pr2_b)
+
+    assert not pr1_b_id.staging_id
+    assert not pr2_b_id.staging_id
+    assert pr1_b_id.batch_id == pr2_b_id.batch_id
+    assert pr1_b_id.state == "opened",\
+        "implicit approval from forward port should have been canceled"
+    batch = pr2_b_id.batch_id
+
+    with r1:
+        r1.post_status(pr1_b_id.head, 'success')
+        r1.get_pr(pr1_b_id.number).post_comment('hansen r+', config['role_reviewer']['token'])
+    env.run_crons()
+
+    assert batch.blocked
+    assert pr1_b_id.blocked
+
+    with r2:
+        r2.post_status(pr2_b.head, "success")
+        pr2_b.post_comment("hansen r+", config['role_reviewer']['token'])
+    env.run_crons()
+
+    assert not batch.blocked
+    assert pr1_b_id.staging_id and pr1_b_id.staging_id == pr2_b_id.staging_id
+
+    with r1, r2:
+        r1.post_status('staging.b', 'success')
+        r2.post_status('staging.b', 'success')
+    env.run_crons()
+
+    def find_child(pr):
+        return env['runbot_merge.pull_requests'].search([
+            ('parent_id', '=', pr.id),
+        ])
+    pr1_c_id = find_child(pr1_b_id)
+    assert pr1_c_id
+    pr2_c_id = find_child(pr2_b_id)
+    assert pr2_c_id
+
+    with r1, r2:
+        r1.post_status(pr1_c_id.head, 'success')
+        r2.post_status(pr2_c_id.head, 'success')
+    env.run_crons()
+
+    assert find_child(pr1_c_id)
+    assert find_child(pr2_c_id)