CLI: Fix verdi process [show|report|status|watch|call-root] no output

The commands take one or more processes, but if no processes were
provided no output was shown whatsoever which can be confusing to the
user. Now an error is now shown if no processes are defined.

src/aiida/cmdline/commands/cmd_process.py

@@ -188,6 +188,11 @@ def process_show(processes, most_recent_node):
     """Show details for one or multiple processes."""
     from aiida.cmdline.utils.common import get_node_info
 
+    if not processes and not most_recent_node:
+        raise click.UsageError(
+            'Please specify one or multiple processes by their identifier (PK, UUID or label) or use an option.'
+        )
+
     if processes and most_recent_node:
         raise click.BadOptionUsage(
             'most_recent_node',
@@ -206,6 +211,8 @@ def process_show(processes, most_recent_node):
 @decorators.with_dbenv()
 def process_call_root(processes):
     """Show root process of the call stack for the given processes."""
+    if not processes:
+        raise click.UsageError('Please specify one or multiple processes by their identifier (PK, UUID or label).')
     for process in processes:
         caller = process.caller
 
@@ -244,6 +251,11 @@ def process_report(processes, most_recent_node, levelname, indent_size, max_dept
     from aiida.cmdline.utils.common import get_calcjob_report, get_process_function_report, get_workchain_report
     from aiida.orm import CalcFunctionNode, CalcJobNode, WorkChainNode, WorkFunctionNode
 
+    if not processes and not most_recent_node:
+        raise click.UsageError(
+            'Please specify one or multiple processes by their identifier (PK, UUID or label) or use an option.'
+        )
+
     if processes and most_recent_node:
         raise click.BadOptionUsage(
             'most_recent_node',
@@ -275,6 +287,11 @@ def process_status(call_link_label, most_recent_node, max_depth, processes):
     """Print the status of one or multiple processes."""
     from aiida.cmdline.utils.ascii_vis import format_call_graph
 
+    if not processes and not most_recent_node:
+        raise click.UsageError(
+            'Please specify one or multiple processes by their identifier (PK, UUID or label) or use an option.'
+        )
+
     if processes and most_recent_node:
         raise click.BadOptionUsage(
             'most_recent_node',
@@ -299,6 +316,11 @@ def process_kill(processes, all_entries, timeout, wait):
     """Kill running processes."""
     from aiida.engine.processes import control
 
+    if not processes and not all_entries:
+        raise click.UsageError(
+            'Please specify one or multiple processes by their identifier (PK, UUID or label) or use an option.'
+        )
+
     if processes and all_entries:
         raise click.BadOptionUsage('all', 'cannot specify individual processes and the `--all` flag at the same time.')
 
@@ -326,6 +348,11 @@ def process_pause(processes, all_entries, timeout, wait):
     """Pause running processes."""
     from aiida.engine.processes import control
 
+    if not processes and not all_entries:
+        raise click.UsageError(
+            'Please specify one or multiple processes by their identifier (PK, UUID or label) or use an option.'
+        )
+
     if processes and all_entries:
         raise click.BadOptionUsage('all', 'cannot specify individual processes and the `--all` flag at the same time.')
 
@@ -350,6 +377,11 @@ def process_play(processes, all_entries, timeout, wait):
     """Play (unpause) paused processes."""
     from aiida.engine.processes import control
 
+    if not processes and not all_entries:
+        raise click.UsageError(
+            'Please specify one or multiple processes by their identifier (PK, UUID or label) or use an option.'
+        )
+
     if processes and all_entries:
         raise click.BadOptionUsage('all', 'cannot specify individual processes and the `--all` flag at the same time.')
 
@@ -370,6 +402,10 @@ def process_play(processes, all_entries, timeout, wait):
 @decorators.only_if_daemon_running(echo.echo_warning, 'daemon is not running, so process may not be reachable')
 def process_watch(broker, processes):
     """Watch the state transitions for a process."""
+
+    if not processes:
+        raise click.UsageError('Please specify one or multiple processes by their identifier (PK, UUID or label).')
+
     from time import sleep
 
     from kiwipy import BroadcastFilter

src/aiida/cmdline/utils/echo.py

@@ -35,6 +35,7 @@ class ExitCode(enum.IntEnum):
     """Exit codes for the verdi command line."""
 
     CRITICAL = 1
+    USAGE_ERROR = 2
     DEPRECATED = 80
     UNKNOWN = 99
     SUCCESS = 0

tests/cmdline/commands/test_process.py

@@ -206,11 +206,11 @@ def test_process_show(self, run_cli_command):
         calcjob_one.store()
         calcjob_two.store()
 
-        # Running without identifiers should not except and not print anything
+        # Running without identifiers should except and print something
         options = []
-        result = run_cli_command(cmd_process.process_show, options)
-
-        assert len(result.output_lines) == 0
+        result = run_cli_command(cmd_process.process_show, options, raises=True)
+        assert result.exit_code == ExitCode.USAGE_ERROR
+        assert len(result.output_lines) > 0
 
         # Giving a single identifier should print a non empty string message
         options = [str(workchain_one.pk)]
@@ -232,11 +232,11 @@ def test_process_report(self, run_cli_command):
         """Test verdi process report"""
         node = WorkflowNode().store()
 
-        # Running without identifiers should not except and not print anything
+        # Running without identifiers should except and print something
         options = []
-        result = run_cli_command(cmd_process.process_report, options)
-
-        assert len(result.output_lines) == 0
+        result = run_cli_command(cmd_process.process_report, options, raises=True)
+        assert result.exit_code == ExitCode.USAGE_ERROR
+        assert len(result.output_lines) > 0
 
         # Giving a single identifier should print a non empty string message
         options = [str(node.pk)]
@@ -255,11 +255,11 @@ def test_process_status(self, run_cli_command):
         node = WorkflowNode().store()
         node.set_process_state(ProcessState.RUNNING)
 
-        # Running without identifiers should not except and not print anything
+        # Running without identifiers should except and print something
         options = []
-        result = run_cli_command(cmd_process.process_status, options)
-        assert result.exception is None, result.output
-        assert len(result.output_lines) == 0
+        result = run_cli_command(cmd_process.process_status, options, raises=True)
+        assert result.exit_code == ExitCode.USAGE_ERROR
+        assert len(result.output_lines) > 0
 
         # Giving a single identifier should print a non empty string message
         options = [str(node.pk)]
@@ -273,6 +273,15 @@ def test_process_status(self, run_cli_command):
         assert result.exception is None, result.output
         assert len(result.output_lines) == 0
 
+    @pytest.mark.requires_rmq
+    def test_process_watch(self, run_cli_command):
+        """Test verdi process watch"""
+        # Running without identifiers should except and print something
+        options = []
+        result = run_cli_command(cmd_process.process_watch, options, raises=True)
+        assert result.exit_code == ExitCode.USAGE_ERROR
+        assert len(result.output_lines) > 0
+
     def test_process_status_call_link_label(self, run_cli_command):
         """Test ``verdi process status --call-link-label``."""
         node = WorkflowNode().store()
@@ -460,6 +469,13 @@ def test_multiple_processes(self, run_cli_command):
         assert str(self.node_root.pk) in result.output_lines[1]
         assert str(self.node_root.pk) in result.output_lines[2]
 
+    def test_no_process_argument(self, run_cli_command):
+        # Running without identifiers should except and print something
+        options = []
+        result = run_cli_command(cmd_process.process_call_root, options, raises=True)
+        assert result.exit_code == ExitCode.USAGE_ERROR
+        assert len(result.output_lines) > 0
+
 
 @pytest.mark.requires_rmq
 @pytest.mark.usefixtures('started_daemon_client')
@@ -471,6 +487,12 @@ def test_process_pause(submit_and_await, run_cli_command):
     run_cli_command(cmd_process.process_pause, [str(node.pk), '--wait'])
     await_condition(lambda: node.paused)
 
+    # Running without identifiers should except and print something
+    options = []
+    result = run_cli_command(cmd_process.process_pause, options, raises=True)
+    assert result.exit_code == ExitCode.USAGE_ERROR
+    assert len(result.output_lines) > 0
+
 
 @pytest.mark.requires_rmq
 @pytest.mark.usefixtures('started_daemon_client')
@@ -484,6 +506,12 @@ def test_process_play(submit_and_await, run_cli_command):
     run_cli_command(cmd_process.process_play, [str(node.pk), '--wait'])
     await_condition(lambda: not node.paused)
 
+    # Running without identifiers should except and print something
+    options = []
+    result = run_cli_command(cmd_process.process_play, options, raises=True)
+    assert result.exit_code == ExitCode.USAGE_ERROR
+    assert len(result.output_lines) > 0
+
 
 @pytest.mark.requires_rmq
 @pytest.mark.usefixtures('started_daemon_client')
@@ -515,6 +543,12 @@ def test_process_kill(submit_and_await, run_cli_command):
     await_condition(lambda: node.is_killed)
     assert node.process_status == 'Killed through `verdi process kill`'
 
+    # Running without identifiers should except and print something
+    options = []
+    result = run_cli_command(cmd_process.process_kill, options, raises=True)
+    assert result.exit_code == ExitCode.USAGE_ERROR
+    assert len(result.output_lines) > 0
+
 
 @pytest.mark.requires_rmq
 @pytest.mark.usefixtures('started_daemon_client')