exp push/pull: default to head rev

dvc/repo/experiments/pull.py

@@ -21,7 +21,7 @@ logger = logging.getLogger(__name__)
 def pull(  # noqa: C901
     repo,
     git_remote: str,
-    exp_names: Union[Iterable[str], str],
+    exp_names: Optional[Union[Iterable[str], str]] = None,
     all_commits=False,
     rev: Optional[Union[List[str], str]] = None,
     num=1,

dvc/repo/experiments/push.py

@@ -97,7 +97,7 @@ def exp_refs_from_rev(scm: "Git", rev: List[str], num: int = 1) -> Set["ExpRefIn
 def push(
     repo: "Repo",
     git_remote: str,
-    exp_names: Union[List[str], str],
+    exp_names: Optional[Union[List[str], str]] = None,
     all_commits: bool = False,
     rev: Optional[Union[List[str], str]] = None,
     num: int = 1,

tests/func/experiments/test_remote.py

@@ -35,6 +35,9 @@ def test_push(tmp_dir, scm, dvc, git_upstream, exp_stage, use_url):
     dvc.experiments.push(remote, [ref_info1.name])
     assert git_upstream.tmp_dir.scm.get_ref(str(ref_info1)) == exp1
 
+    dvc.experiments.push(remote)
+    assert git_upstream.tmp_dir.scm.get_ref(str(ref_info3)) == exp3
+
 
 @pytest.mark.parametrize("all_,rev,result3", [(True, False, True), (False, True, None)])
 def test_push_args(tmp_dir, scm, dvc, git_upstream, exp_stage, all_, rev, result3):
@@ -173,6 +176,11 @@ def test_list_remote(tmp_dir, scm, dvc, git_downstream, exp_stage, use_url):
 def test_pull(tmp_dir, scm, dvc, git_downstream, exp_stage, use_url):
     from dvc.exceptions import InvalidArgumentError
 
+    # fetch and checkout to downstream so both repos start from same commit
+    downstream_repo = git_downstream.tmp_dir.scm.gitpython.repo
+    fetched = downstream_repo.remote(git_downstream.remote).fetch()
+    downstream_repo.git.checkout(fetched)
+
     remote = git_downstream.url if use_url else git_downstream.remote
     downstream_exp = git_downstream.tmp_dir.dvc.experiments
     with pytest.raises(InvalidArgumentError):
@@ -200,6 +208,9 @@ def test_pull(tmp_dir, scm, dvc, git_downstream, exp_stage, use_url):
     downstream_exp.pull(remote, [str(ref_info1)])
     assert git_downstream.tmp_dir.scm.get_ref(str(ref_info1)) == exp1
 
+    downstream_exp.pull(remote)
+    assert git_downstream.tmp_dir.scm.get_ref(str(ref_info3)) == exp3
+
 
 @pytest.mark.parametrize("all_,rev,result3", [(True, False, True), (False, True, None)])
 def test_pull_args(tmp_dir, scm, dvc, git_downstream, exp_stage, all_, rev, result3):

tests/unit/command/test_experiments.py

@@ -294,12 +294,7 @@ def test_experiments_push(dvc, scm, mocker):
     )
     cmd = cli_args.func(cli_args)
 
-    with pytest.raises(InvalidArgumentError) as exp_info:
-        cmd.run()
-    assert (
-        str(exp_info.value) == "Either provide an `experiment` argument"
-        ", or use the `--rev` or `--all-commits` flag."
-    )
+    assert cmd.run() == 0
 
 
 def test_experiments_pull(dvc, scm, mocker):
@@ -351,12 +346,7 @@ def test_experiments_pull(dvc, scm, mocker):
     )
     cmd = cli_args.func(cli_args)
 
-    with pytest.raises(InvalidArgumentError) as exp_info:
-        cmd.run()
-    assert (
-        str(exp_info.value) == "Either provide an `experiment` argument"
-        ", or use the `--rev` or `--all-commits` flag."
-    )
+    assert cmd.run() == 0
 
 
 def test_experiments_remove_flag(dvc, scm, mocker, capsys, caplog):