schemagen: move test configuration into contrib/schemagen/CMakeLists.txt

Addresses review feedback: keep the schemagen-specific CMake rules
close to the tool instead of inline in the top-level CMakeLists.txt.
The subdirectory file is added from the root and guarded by the same
Python3 availability check that was already in use.

CMakeLists.txt

@@ -163,37 +163,14 @@ target_link_libraries(mytest PRIVATE ${PROJECT_NAME} doctest nanobench simdjson)
 target_compile_options(mytest PRIVATE ${TEST_FLAGS})
 doctest_discover_tests(mytest WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
 
-# schemagen tests
-add_test(
-  NAME schemagen_python_tests
-  COMMAND python3 contrib/schemagen/test_schemagen.py
-  WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
+find_package(Python3 COMPONENTS Interpreter)
+if(Python3_Interpreter_FOUND)
+  add_test(NAME python_bindings
+           COMMAND ${Python3_EXECUTABLE}
+                   ${CMAKE_CURRENT_SOURCE_DIR}/test_python_bindings.py)
+endif()
 
-set(SCHEMAGEN_DIR ${CMAKE_SOURCE_DIR}/contrib/schemagen)
-set(SCHEMAGEN_SCRIPT ${SCHEMAGEN_DIR}/weaseljson_schemagen.py)
-set(EXAMPLE_SCHEMA ${SCHEMAGEN_DIR}/example.schema.json)
-set(GEN_H ${CMAKE_BINARY_DIR}/gen.h)
-
-add_custom_command(
-  OUTPUT ${GEN_H}
-  COMMAND python3 ${SCHEMAGEN_SCRIPT} ${EXAMPLE_SCHEMA} -o ${GEN_H} --namespace
-          weasel_schema
-  DEPENDS ${SCHEMAGEN_SCRIPT} ${EXAMPLE_SCHEMA}
-  COMMENT "Generating gen.h from example.schema.json")
-
-add_custom_target(schemagen_gen_h DEPENDS ${GEN_H})
-
-add_executable(schemagen_example ${SCHEMAGEN_DIR}/test_gen.cpp)
-target_include_directories(schemagen_example PRIVATE include
-                                                     ${CMAKE_BINARY_DIR})
-target_link_libraries(schemagen_example PRIVATE ${PROJECT_NAME})
-target_compile_options(schemagen_example PRIVATE -Wno-switch-enum)
-add_dependencies(schemagen_example schemagen_gen_h)
-
-add_test(
-  NAME schemagen_example
-  COMMAND schemagen_example
-  WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
+add_subdirectory(contrib/schemagen)
 
 include(CMakePushCheckState)
 include(CheckCXXCompilerFlag)

contrib/schemagen/CMakeLists.txt

@@ -0,0 +1,35 @@
+# Tests for contrib/schemagen
+
+if(NOT Python3_Interpreter_FOUND)
+  return()
+endif()
+
+add_test(
+  NAME schemagen_python_tests
+  COMMAND ${Python3_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test_schemagen.py
+  WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
+
+set(SCHEMAGEN_SCRIPT ${CMAKE_CURRENT_SOURCE_DIR}/weaseljson_schemagen.py)
+set(EXAMPLE_SCHEMA ${CMAKE_CURRENT_SOURCE_DIR}/example.schema.json)
+set(GEN_H ${CMAKE_CURRENT_BINARY_DIR}/gen.h)
+
+add_custom_command(
+  OUTPUT ${GEN_H}
+  COMMAND ${Python3_EXECUTABLE} ${SCHEMAGEN_SCRIPT} ${EXAMPLE_SCHEMA} -o
+          ${GEN_H} --namespace weasel_schema
+  DEPENDS ${SCHEMAGEN_SCRIPT} ${EXAMPLE_SCHEMA}
+  COMMENT "Generating gen.h from example.schema.json")
+
+add_custom_target(schemagen_gen_h DEPENDS ${GEN_H})
+
+add_executable(schemagen_example ${CMAKE_CURRENT_SOURCE_DIR}/test_gen.cpp)
+target_include_directories(schemagen_example
+                           PRIVATE include ${CMAKE_CURRENT_BINARY_DIR})
+target_link_libraries(schemagen_example PRIVATE ${PROJECT_NAME})
+target_compile_options(schemagen_example PRIVATE -Wno-switch-enum)
+add_dependencies(schemagen_example schemagen_gen_h)
+
+add_test(
+  NAME schemagen_example
+  COMMAND schemagen_example
+  WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})

test_python_bindings.py

@@ -0,0 +1,90 @@
+import json
+
+import weaseljson
+
+
+class Recorder(weaseljson.WeaselJsonCallbacksBase):
+    def __init__(self):
+        self.keys = []
+        self.strings = []
+        self.numbers = []
+        self.events = []
+        self._current = bytearray()
+
+    def _flush(self, target, data, done):
+        self._current.extend(data)
+        if done:
+            target.append(bytes(self._current))
+            self._current = bytearray()
+
+    def on_begin_object(self):
+        self.events.append("begin_object")
+
+    def on_end_object(self):
+        self.events.append("end_object")
+
+    def on_begin_array(self):
+        self.events.append("begin_array")
+
+    def on_end_array(self):
+        self.events.append("end_array")
+
+    def on_key_data(self, data, done):
+        self._flush(self.keys, data, done)
+
+    def on_string_data(self, data, done):
+        self._flush(self.strings, data, done)
+
+    def on_number_data(self, data, done):
+        self._flush(self.numbers, data, done)
+
+    def on_true_literal(self):
+        self.events.append("true")
+
+    def on_false_literal(self):
+        self.events.append("false")
+
+    def on_null_literal(self):
+        self.events.append("null")
+
+
+def parse_all(parser, data):
+    for i in range(len(data)):
+        status = parser.parse(data[i : i + 1])
+        if status != weaseljson.WeaselJsonStatus.AGAIN:
+            return status
+    return parser.parse(b"")
+
+
+def test_object_keys_routed_correctly():
+    recorder = Recorder()
+    with weaseljson.WeaselJsonParser(recorder) as parser:
+        status = parse_all(
+            parser, json.dumps({"hello": "world", "foo": "bar"}).encode()
+        )
+
+    assert status == weaseljson.WeaselJsonStatus.OK, status
+    assert recorder.keys == [b"hello", b"foo"], recorder.keys
+    assert recorder.strings == [b"world", b"bar"], recorder.strings
+
+
+def test_mixed_values():
+    recorder = Recorder()
+    with weaseljson.WeaselJsonParser(recorder) as parser:
+        status = parse_all(
+            parser,
+            json.dumps({"answer": 42, "yes": True, "no": False, "nil": None}).encode(),
+        )
+
+    assert status == weaseljson.WeaselJsonStatus.OK, status
+    assert recorder.keys == [b"answer", b"yes", b"no", b"nil"], recorder.keys
+    assert recorder.numbers == [b"42"], recorder.numbers
+    assert recorder.events.count("true") == 1
+    assert recorder.events.count("false") == 1
+    assert recorder.events.count("null") == 1
+
+
+if __name__ == "__main__":
+    test_object_keys_routed_correctly()
+    test_mixed_values()
+    print("python bindings ok")

weaseljson.py

@@ -15,6 +15,7 @@ class WeaselJsonCallbacks(ctypes.Structure):
         ("on_begin_object", event_callback),
         ("on_end_object", event_callback),
         ("on_string_data", data_callback),
+        ("on_key_data", data_callback),
         ("on_begin_array", event_callback),
         ("on_end_array", event_callback),
         ("on_number_data", data_callback),
@@ -41,6 +42,9 @@ class WeaselJsonCallbacksBase:
     def on_string_data(self, data, done):
         pass
 
+    def on_key_data(self, data, done):
+        pass
+
     def on_begin_array(self):
         pass
 
@@ -151,6 +155,12 @@ def on_string_data(p, buf, len, done):
     self.on_string_data(bytes(ctypes.string_at(buf, len)), bool(done))
 
 
+@ctypes.CFUNCTYPE(None, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_int, ctypes.c_int)
+def on_key_data(p, buf, len, done):
+    self = ctypes.cast(p, ctypes.POINTER(ctypes.py_object)).contents.value
+    self.on_key_data(bytes(ctypes.string_at(buf, len)), bool(done))
+
+
 @ctypes.CFUNCTYPE(None, ctypes.c_void_p)
 def on_begin_array(p):
     self = ctypes.cast(p, ctypes.POINTER(ctypes.py_object)).contents.value
@@ -191,6 +201,7 @@ c_callbacks = WeaselJsonCallbacks(
     on_begin_object,
     on_end_object,
     on_string_data,
+    on_key_data,
     on_begin_array,
     on_end_array,
     on_number_data,
@@ -206,6 +217,7 @@ class MyCallbacks(WeaselJsonCallbacksBase):
         print(data)
 
 
+if __name__ == "__main__":
     with WeaselJsonParser(MyCallbacks()) as parser:
         raw = json.dumps({"hello": "world", "foo": 42}).encode()
         i = 0