1 files changed, 94 insertions, 0 deletions
diff --git a/molecule/default/tests/test_lineinfile_strategy.py b/molecule/default/tests/test_lineinfile_strategy.py
new file mode 100644
index 0000000..b75a656
--- /dev/null
+++ b/molecule/default/tests/test_lineinfile_strategy.py
@@ -0,0 +1,94 @@
+import yaml
+
+
+testinfra_hosts = ["prometheus"]
+
+
+def read_file(host, path):
+    target = host.file(path)
+    assert target.exists
+    return target
+
+
+def read_yaml_file(host, path):
+    return yaml.safe_load(read_file(host, path).content_string)
+
+
+def test_lineinfile_bootstrap_adds_first_host_without_breaking_yaml(host):
+    target = read_file(host, "/opt/lineinfile_first_host.yml")
+
+    assert target.user == "prometheus"
+    assert target.group == "prometheus"
+    assert target.mode == 0o600
+    assert read_yaml_file(host, "/opt/lineinfile_first_host.yml") == ["application:9100"]
+
+
+def test_lineinfile_adds_subsequent_host_to_existing_yaml(host):
+    target = read_file(host, "/opt/lineinfile_bootstrap.yml")
+
+    assert target.content_string == (
+        "- labels:\n"
+        "    my: label\n"
+        "  targets:\n"
+        "  - existing:9100\n"
+        "  - application:9100\n"
+    )
+
+    assert read_yaml_file(host, "/opt/lineinfile_bootstrap.yml") == [
+        {"labels": {"my": "label"}, "targets": ["existing:9100", "application:9100"]}
+    ]
+
+
+def test_lineinfile_parallel_writes_keep_all_hosts_and_parse(host):
+    hosts = sorted(read_yaml_file(host, "/opt/lineinfile_parallel.yml"))
+    assert hosts == [
+        "application2:9100",
+        "application3:9100",
+        "application4:9100",
+        "application:9100",
+    ]
+
+
+def test_lineinfile_user_edited_file_stays_parseable(host):
+    target = read_file(host, "/opt/lineinfile_user_edited.yml")
+
+    assert target.content_string == (
+        "# user comment\n"
+        "- labels:\n"
+        "    env: prod\n"
+        "  targets:\n"
+        "  - existing:9100\n"
+        "  - application2:9100\n"
+    )
+
+    assert read_yaml_file(host, "/opt/lineinfile_user_edited.yml") == [
+        {"labels": {"env": "prod"}, "targets": ["existing:9100", "application2:9100"]}
+    ]
+
+
+def test_lineinfile_removing_last_host_still_leaves_parseable_yaml(host):
+    assert read_yaml_file(host, "/opt/lineinfile_remove_last.yml") == [
+        {"labels": {"env": "stage"}, "targets": None}
+    ]
+
+
+def test_lineinfile_compatibility_simple_and_prefix_cases(host):
+    assert read_yaml_file(host, "/opt/simple_target1.yml") == ["application"]
+    assert read_yaml_file(host, "/opt/simple_target2.yml") == ["test1", "test2"]
+    assert read_yaml_file(host, "/opt/simple_target3.yml") == ["application_AA"]
+    assert read_yaml_file(host, "/opt/simple_target4.yml") == ["exporter_without_id"]
+    assert read_yaml_file(host, "/opt/prefix_target1.yml") == ["application"]
+    assert read_yaml_file(host, "/opt/prefix_target2.yml") == ["application"]
+    assert read_yaml_file(host, "/opt/prefix/prefix_target3.yml") == ["application"]
+
+
+def test_lineinfile_hooks_still_run(host):
+    assert sorted(read_yaml_file(host, "/opt/hook_target.yml")) == [
+        "application",
+        "application2",
+        "application3",
+        "application4",
+    ]
+
+    assert host.file("/opt/hook1").exists
+    assert host.file("/opt/hook2").content_string == "hello\nhello\nhello\nhello\n"