Create backup for jobs.json when running in existing runpath

src/ert/enkf_main.py

@@ -368,6 +368,8 @@ def createRunPath(self, run_context: RunContext) -> None:
                     run_context.iteration,
                 )
 
+                path = run_path / "jobs.json"
+                _backup_if_existing(path)
                 with open(run_path / "jobs.json", mode="w", encoding="utf-8") as fptr:
                     forward_model_output = ert_config.forward_model_data_to_json(
                         run_arg.run_id,

tests/unit_tests/test_enkf_runpath.py

@@ -47,3 +47,23 @@ def test_without_gen_kw(prior_ensemble):
     )
     assert len(os.listdir("storage/snake_oil/runpath")) == 1
     assert len(os.listdir("storage/snake_oil/runpath/realization-0")) == 1
+
+
+def test_jobs_file_is_backed_up(copy_case, storage):
+    copy_case("snake_oil")
+    ert_config = ErtConfig.from_file("snake_oil.ert")
+    main = EnKFMain(ert_config)
+    experiment_id = storage.create_experiment(
+        parameters=ert_config.ensemble_config.parameter_configuration
+    )
+    prior_ensemble = storage.create_ensemble(
+        experiment_id, name="prior", ensemble_size=5
+    )
+    prior = main.ensemble_context(prior_ensemble, [True], 0)
+    main.sample_prior(prior.sim_fs, prior.active_realizations)
+    main.createRunPath(prior)
+    assert os.path.exists("storage/snake_oil/runpath/realization-0/iter-0/jobs.json")
+    main.createRunPath(prior)
+    iter0_output_files = os.listdir("storage/snake_oil/runpath/realization-0/iter-0/")
+    jobs_files = [f for f in iter0_output_files if f.startswith("jobs.json")]
+    assert len(jobs_files) > 1, "No backup created for jobs.json"