From 3fb19efbb2ef231683f3c27a5b6b669c33ab98c5 Mon Sep 17 00:00:00 2001
From: Zeid <zeid@mozilla.com>
Date: Thu, 12 Mar 2026 14:50:30 -0400
Subject: [PATCH] test_landings: add test_deferred_jobs (bug 2021883)

- add a patch that can be applied over and over again
- add test that simulates a queue with two different repos
---
 src/lando/api/tests/test_landings.py | 101 +++++++++++++++++++++++++++
 src/lando/conftest.py                |  14 ++++
 2 files changed, 115 insertions(+)

diff --git a/src/lando/api/tests/test_landings.py b/src/lando/api/tests/test_landings.py
index 35c165724..5b715c092 100644
--- a/src/lando/api/tests/test_landings.py
+++ b/src/lando/api/tests/test_landings.py
@@ -1381,6 +1381,107 @@ def _make_handover_job(target_repo: Repo, handover_repo: Repo) -> LandingJob:
     return _make_handover_job
 
 
+@pytest.mark.django_db
+def test_deferred_jobs(
+    repo_mc: Callable,
+    treestatusdouble: TreeStatusDouble,
+    get_landing_worker: Callable,
+    make_landing_job,
+    create_patch_revision,
+    normal_patch,
+    mock_phab_trigger_repo_update_apply_async: mock.Mock,
+):
+    # This test simulates a number of jobs in two different repos
+    # being submitted, and ensures that when closing a tree the
+    # queue is not blocked by the jobs in the queue that target
+    # the closed tree.
+
+    def refresh(jobs):
+        [job.refresh_from_db() for job in jobs]
+
+    git_repo_1 = repo_mc(SCMType.GIT, hooks_enabled=False, name="repo1")
+    git_repo_2 = repo_mc(SCMType.GIT, hooks_enabled=False, name="repo2")
+    git_worker = get_landing_worker(SCMType.GIT)
+    git_worker.worker_instance.applicable_repos.add(git_repo_1)
+    git_worker.worker_instance.applicable_repos.add(git_repo_2)
+
+    treestatusdouble.open_tree(git_repo_1.name)
+    treestatusdouble.open_tree(git_repo_2.name)
+    git_worker.refresh_active_repos()
+
+    job_params = {
+        "status": JobStatus.SUBMITTED,
+        "requester_email": "test@example.com",
+    }
+
+    job_params["target_repo"] = git_repo_1
+    jobs = []
+    for i in (1, 2, 3):
+        jobs.append(
+            make_landing_job(
+                revisions=[
+                    create_patch_revision(1, patch=normal_patch(3), revision_id=i)
+                ],
+                **job_params,
+            )
+        )
+
+    job_params["target_repo"] = git_repo_2
+    for i in (4, 5, 6):
+        jobs.append(
+            make_landing_job(
+                revisions=[
+                    create_patch_revision(1, patch=normal_patch(3), revision_id=i)
+                ],
+                **job_params,
+            )
+        )
+
+    assert LandingJob.objects.all().count() == 6
+    assert all(
+        job.status == JobStatus.SUBMITTED for job in LandingJob.objects.all()
+    ), "All jobs should be in a submitted state."
+
+    git_worker.start(max_loops=1)
+    refresh(jobs)
+
+    assert jobs[0].status == JobStatus.LANDED, "First job should have landed."
+
+    # Close first tree.
+    treestatusdouble.close_tree(git_repo_1.name)
+    git_worker.start(max_loops=1)
+
+    # Second job should be deferred now, since we did not refresh active repos.
+    # All remaining jobs should be submitted. Active repos are refreshed when
+    # the last job did not complete.
+    refresh(jobs)
+    assert jobs[1].status == JobStatus.DEFERRED, "Second job should be deferred."
+    assert all(
+        job.status == JobStatus.SUBMITTED for job in jobs[2:]
+    ), "Remaining jobs should be submitted."
+
+    git_worker.start(max_loops=10)
+    refresh(jobs)
+    assert all(
+        job.status == JobStatus.LANDED for job in jobs[3:]
+    ), "Remaining repo2 jobs should be landed."
+
+    refresh(jobs)
+    assert (
+        jobs[1].status == JobStatus.DEFERRED
+    ), "Second repo1 job should still be deferred."
+    assert (
+        jobs[2].status == JobStatus.SUBMITTED
+    ), "Third repo1 job should still be submitted."
+
+    treestatusdouble.open_tree(git_repo_1.name)
+    git_worker.start(max_loops=5)
+    refresh(jobs)
+    assert all(
+        job.status == JobStatus.LANDED for job in jobs
+    ), "All jobs should have landed."
+
+
 @pytest.mark.parametrize(
     "closed_repos,",
     [
diff --git a/src/lando/conftest.py b/src/lando/conftest.py
index e31785a81..59edc2e9b 100644
--- a/src/lando/conftest.py
+++ b/src/lando/conftest.py
@@ -98,6 +98,17 @@
 +TEST
 """.lstrip()
 
+PATCH_NORMAL_4 = r"""
+# HG changeset patch
+# User Test User <test@example.com>
+# Date 0 0
+#      Thu Jan 01 00:00:00 1970 +0000
+# Diff Start Line 7
+no bug: patch that applies over and over
+diff --git a/{filename} b/{filename}
+new file mode 100644
+""".lstrip()
+
 PATCH_GIT_1 = """\
 From dd187015cd85d59c2a65a3a18c67b2b05e7739b9 Mon Sep 17 00:00:00 2001
 From: Py Test <pytest@lando.example.net>
@@ -213,9 +224,12 @@ def normal_patch():
         PATCH_NORMAL_1,
         PATCH_NORMAL_2,
         PATCH_NORMAL_3,
+        PATCH_NORMAL_4,
     ]
 
     def _patch(number=0):
+        if number == 3:
+            return PATCH_NORMAL_4.format(filename=uuid.uuid4())
         return _patches[number]
 
     return _patch