plugins: refactor the tests for dynamic plugins

This adapts the test to the new 'plugin' command: no more sleeping,
since we are synchronous !

This tests the timeout by increasing the 'slowinit' plugin sleep
duration at init reception.

This adds a broken plugin to make sure we won't crash because of a
misbehaving plugin (unmet dependency is the most common case).

tests/plugins/broken.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+"""Simple plugin to test that lightningd doesnt crash if it starts a
+misbehaving plugin via RPC.
+"""
+
+from lightning import Plugin
+import an_unexistent_module_that_will_make_me_crash
+
+plugin = Plugin(dynamic=False)
+
+
+@plugin.init()
+def init(options, configuration, plugin):
+    plugin.log("broken.py initializing {}".format(configuration))
+    # We need to actually use the import to pass source checks..
+    an_unexistent_module_that_will_make_me_crash.hello()
+
+
+plugin.run()

tests/plugins/slow_init.py

@@ -8,7 +8,7 @@ plugin = Plugin()
 @plugin.init()
 def init(options, configuration, plugin):
     plugin.log("slow_init.py initializing {}".format(configuration))
-    time.sleep(1)
+    time.sleep(2)
 
 
 plugin.run()

tests/test_plugin.py

@@ -94,11 +94,10 @@ def test_plugin_dir(node_factory):
 
 
 def test_plugin_slowinit(node_factory):
-    """Tests the 'plugin' RPC command when init is slow"""
+    """Tests that the 'plugin' RPC command times out if plugin doesnt respond"""
     n = node_factory.get_node()
 
     n.rpc.plugin_start(os.path.join(os.getcwd(), "tests/plugins/slow_init.py"))
-    n.daemon.wait_for_log("slow_init.py initializing.* 'startup': False")
 
     # It's not actually configured yet, see what happens;
     # make sure 'rescan' and 'list' controls dont crash
@@ -116,42 +115,47 @@ def test_plugin_command(node_factory):
     assert(len(cmd) == 0)
 
     # Add the 'contrib/plugins' test dir
-    time.sleep(2)
     n.rpc.plugin_startdir(directory=os.path.join(os.getcwd(), "contrib/plugins"))
-    n.daemon.wait_for_log(r"Plugin helloworld.py initialized")
     # Make sure that the 'hello' command from the helloworld.py plugin
     # is now available.
     cmd = [hlp for hlp in n.rpc.help()["help"] if "hello" in hlp["command"]]
     assert(len(cmd) == 1)
 
-    # Make sure 'rescan' and 'list' controls dont crash
+    # Make sure 'rescan' and 'list' subcommands dont crash
     n.rpc.plugin_rescan()
     n.rpc.plugin_list()
-    time.sleep(1)
 
     # Make sure the plugin behaves normally after stop and restart
-    n.rpc.plugin_stop(plugin="helloworld.py")
+    assert("Successfully stopped helloworld.py." == n.rpc.plugin_stop(plugin="helloworld.py")[''])
     n.daemon.wait_for_log(r"Killing plugin: helloworld.py")
-    time.sleep(1)
     n.rpc.plugin_start(plugin=os.path.join(os.getcwd(), "contrib/plugins/helloworld.py"))
     n.daemon.wait_for_log(r"Plugin helloworld.py initialized")
     assert("Hello world" == n.rpc.call(method="hello"))
 
     # Now stop the helloworld plugin
-    n.rpc.plugin_stop(plugin="helloworld.py")
+    assert("Successfully stopped helloworld.py." == n.rpc.plugin_stop(plugin="helloworld.py")[''])
     n.daemon.wait_for_log(r"Killing plugin: helloworld.py")
-    time.sleep(1)
     # Make sure that the 'hello' command from the helloworld.py plugin
     # is not available anymore.
     cmd = [hlp for hlp in n.rpc.help()["help"] if "hello" in hlp["command"]]
     assert(len(cmd) == 0)
 
-    # Test that we cannot stop a plugin with 'dynamic' set to False in
+    # Test that we cannot start a plugin with 'dynamic' set to False in
     # getmanifest
-    n.rpc.plugin_start(plugin=os.path.join(os.getcwd(), "tests/plugins/static.py"))
-    n.daemon.wait_for_log(r"Static plugin initialized.")
-    with pytest.raises(RpcError, match=r"plugin cannot be managed when lightningd is up"):
-        n.rpc.plugin_stop(plugin="static.py")
+    with pytest.raises(RpcError, match=r"Not a dynamic plugin"):
+        n.rpc.plugin_start(plugin=os.path.join(os.getcwd(), "tests/plugins/static.py"))
+
+    # Test that we cannot stop a started plugin with 'dynamic' flag set to
+    # False
+    n2 = node_factory.get_node(options={
+        "plugin": os.path.join(os.getcwd(), "tests/plugins/static.py")
+    })
+    with pytest.raises(RpcError, match=r"static.py cannot be managed when lightningd is up"):
+        n2.rpc.plugin_stop(plugin="static.py")
+
+    # Test that we don't crash when starting a broken plugin
+    with pytest.raises(RpcError, match=r"Timed out while waiting for plugin response"):
+        n2.rpc.plugin_start(plugin=os.path.join(os.getcwd(), "tests/plugins/broken.py"))
 
 
 def test_plugin_disable(node_factory):