Support deprecated message and fields (#126)

tests/inputs/deprecated/deprecated.json

@@ -0,0 +1,4 @@
+{
+  "v": 10,
+  "value": 10
+}

tests/inputs/deprecated/deprecated.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+// Some documentation about the Test message.
+message Test {
+    // Some documentation about the value.
+    option deprecated = true;
+    int32 v = 1 [deprecated=true];
+    int32 value = 2;
+}

tests/inputs/deprecated_field/deprecated_field.json

@@ -0,0 +1,4 @@
+{
+  "v": 10,
+  "value": 10
+}

tests/inputs/deprecated_field/deprecated_field.proto

@@ -0,0 +1,8 @@
+syntax = "proto3";
+
+// Some documentation about the Test message.
+message Test {
+    // Some documentation about the value.
+    int32 v = 1 [deprecated=true];
+    int32 value = 2;
+}

tests/test_deprecated.py

@@ -0,0 +1,26 @@
+import pytest
+
+from tests.output_betterproto.deprecated import Test as DeprecatedMessageTest
+from tests.output_betterproto.deprecated_field import Test as DeprecatedFieldTest
+
+
+def test_deprecated_message():
+    with pytest.deprecated_call():
+        DeprecatedMessageTest(value=10)
+
+
+def test_deprecated_message_with_deprecated_field():
+    with pytest.warns(None) as record:
+        DeprecatedMessageTest(v=10, value=10)
+    assert len(record) == 2
+
+
+def test_deprecated_field_warning():
+    with pytest.deprecated_call():
+        DeprecatedFieldTest(v=10, value=10)
+
+
+def test_deprecated_field_no_warning():
+    with pytest.warns(None) as record:
+        DeprecatedFieldTest(value=10)
+    assert not record