tests/codegen: Add checks for signal emission enums

These are checked to be correct by code compilation, but let's ensure we
also have some kind of forma check on the expected syntax.

gio/tests/codegen.py

@@ -60,6 +60,27 @@ class TestCodegen(unittest.TestCase):
     # Track the cwd, we want to back out to that to clean up our tempdir
     cwd = ""
 
+    ARGUMENTS_TYPES = {
+        "b": {},
+        "y": {},
+        "n": {},
+        "q": {},
+        "i": {},
+        "u": {},
+        "x": {},
+        "t": {},
+        "d": {},
+        "s": {},
+        "o": {},
+        "g": {},
+        "h": {},
+        "ay": {},
+        "as": {},
+        "ao": {},
+        "aay": {},
+        "asv": {"variant_type": "a{sv}"},
+    }
+
     def setUp(self):
         self.timeout_seconds = 6  # seconds per test
         self.tmpdir = tempfile.TemporaryDirectory()
@@ -665,6 +686,117 @@ G_END_DECLS
         self.assertEqual(result.out.strip().count("GDBusCallFlags call_flags,"), 2)
         self.assertEqual(result.out.strip().count("gint timeout_msec,"), 2)
 
+    @unittest.skipIf(on_win32(), "requires /dev/stdout")
+    def test_generate_signal_id_simple_signal(self):
+        """Test that signals IDs are used to emit signals"""
+        interface_xml = """
+            <node>
+              <interface name="org.project.UsefulInterface">
+                <signal name="SimpleSignal"/>
+              </interface>
+              <interface name="org.project.OtherIface">
+                <signal name="SimpleSignal"/>
+              </interface>
+            </node>"""
+
+        result = self.runCodegenWithInterface(
+            interface_xml, "--output", "/dev/stdout", "--body"
+        )
+        stripped_out = result.out.strip()
+        self.assertFalse(result.err)
+        self.assertIs(stripped_out.count("g_signal_emit_by_name ("), 0)
+
+        for iface in ["USEFUL_INTERFACE", "OTHER_IFACE"]:
+            enum_name = f"_ORG_PROJECT_{iface}_SIGNALS"
+            enum_item = f"_ORG_PROJECT_{iface}_SIMPLE_SIGNAL"
+            self.assertIs(stripped_out.count(f"{enum_item},"), 1)
+            self.assertIs(stripped_out.count(f"{enum_name}[{enum_item}] ="), 1)
+            self.assertIs(
+                stripped_out.count(
+                    f" g_signal_emit (object, {enum_name}[{enum_item}], 0);"
+                ),
+                1,
+            )
+
+    @unittest.skipIf(on_win32(), "requires /dev/stdout")
+    def test_generate_signal_id_multiple_signals_types(self):
+        """Test that signals IDs are used to emit signals for all types"""
+
+        signal_template = "<signal name='{}'><arg name='{}' type='{}'/></signal>"
+        generated_signals = [
+            signal_template.format(
+                f"SingleArgSignal{t.upper()}", f"an_{t}", props.get("variant_type", t)
+            )
+            for t, props in self.ARGUMENTS_TYPES.items()
+        ]
+
+        interface_xml = f"""
+            <node>
+              <interface name="org.project.SignalingIface">
+                <signal name="NoArgSignal" />
+                {''.join(generated_signals)}
+              </interface>
+            </node>"""
+
+        result = self.runCodegenWithInterface(
+            interface_xml, "--output", "/dev/stdout", "--body"
+        )
+        stripped_out = result.out.strip()
+        self.assertFalse(result.err)
+        self.assertIs(stripped_out.count("g_signal_emit_by_name ("), 0)
+
+        iface = "SIGNALING_IFACE"
+        for t in self.ARGUMENTS_TYPES.keys():
+            enum_name = f"_ORG_PROJECT_{iface}_SIGNALS"
+            enum_item = f"_ORG_PROJECT_{iface}_SINGLE_ARG_SIGNAL_{t.upper()}"
+            self.assertIs(stripped_out.count(f"{enum_item},"), 1)
+            self.assertIs(stripped_out.count(f"{enum_name}[{enum_item}] ="), 1)
+            self.assertIs(
+                stripped_out.count(
+                    f" g_signal_emit (object, {enum_name}[{enum_item}], 0, arg_an_{t});"
+                ),
+                1,
+            )
+
+    @unittest.skipIf(on_win32(), "requires /dev/stdout")
+    def test_generate_signal_id_multiple_signal_args_types(self):
+        """Test that signals IDs are used to emit signals for all types"""
+
+        generated_args = [
+            f"<arg name='an_{t}' type='{props.get('variant_type', t)}'/>\n"
+            for t, props in self.ARGUMENTS_TYPES.items()
+        ]
+
+        interface_xml = f"""
+            <node>
+              <interface name="org.project.SignalingIface">
+                <signal name="SignalWithManyArgs">
+                    {''.join(generated_args)}
+                </signal>
+              </interface>
+            </node>"""
+
+        result = self.runCodegenWithInterface(
+            interface_xml, "--output", "/dev/stdout", "--body"
+        )
+        stripped_out = result.out.strip()
+        self.assertFalse(result.err)
+        self.assertIs(stripped_out.count("g_signal_emit_by_name ("), 0)
+
+        iface = "SIGNALING_IFACE"
+        enum_name = f"_ORG_PROJECT_{iface}_SIGNALS"
+        enum_item = f"_ORG_PROJECT_{iface}_SIGNAL_WITH_MANY_ARGS"
+        self.assertIs(stripped_out.count(f"{enum_item},"), 1)
+        self.assertIs(stripped_out.count(f"{enum_name}[{enum_item}] ="), 1)
+
+        args = ", ".join([f"arg_an_{t}" for t in self.ARGUMENTS_TYPES.keys()])
+        self.assertIs(
+            stripped_out.count(
+                f" g_signal_emit (object, {enum_name}[{enum_item}], 0, {args});"
+            ),
+            1,
+        )
+
     def test_generate_valid_docbook(self):
         """Test the basic functionality of the docbook generator."""
         xml_contents = """