test_json_stream.py

# SPDX-FileCopyrightText: 2025 Justin Myers
#
# SPDX-License-Identifier: Unlicense

import json
import math
import pytest
import adafruit_json_stream


# pylint: disable=invalid-name,pointless-statement,redefined-outer-name


# ---------------
# Helpers
# ---------------


class BytesChunkIO:
    def __init__(self, data=b"", chunk_size=10):
        self.chunk_size = chunk_size
        self.chunks_read = 0
        self.data = data
        self.data_len = len(self.data)
        self.position = 0

    def __iter__(self):
        return self

    def __next__(self):
        if self.position > self.data_len:
            raise StopIteration

        end = self.chunk_size
        if self.position + end > self.data_len:
            end = self.data_len
        chunk = self.data[self.position : self.position + self.chunk_size]

        self.chunks_read += 1
        self.position += self.chunk_size

        return chunk

    def get_chunks_read(self):
        return self.chunks_read


# ---------------
# Fixtures
# ---------------


@pytest.fixture
def dict_with_all_types():
    return """
    {
        "_check": "{\\\"a\\\": 1, \\\"b\\\": [2,3]}",
        "bool": true,
        "dict": {"key": "value"},
        "float": 1.1,
        "int": 1,
        "list": [1,2,3],
        "null": null,
        "string": "string"
    }
    """


@pytest.fixture
def list_with_values():
    return """
    [
        1,
        2,
        3
    ]
    """


@pytest.fixture
def dict_with_keys():
    return """
    {
        "field_1": 1,
        "field_2": 2,
        "field_3": 3
    }
    """


@pytest.fixture
def dict_with_list_with_single_entries():
    return """
    {
        "list_1": [
            {
                "dict_id": 1
            },
            {
                "dict_id": 2
            },
            {
                "dict_id": 3
            },
            {
                "dict_id": 4
            }
        ]
    }
    """


@pytest.fixture
def complex_dict():
    return """
    {
        "list_1": [
            {
                "dict_id": 1,
                "dict_name": "one",
                "sub_dict": {
                    "sub_dict_id": 1.1,
                    "sub_dict_name": "one point one"
                },
                "sub_list": [
                    "a",
                    "b",
                    "c"
                ]
            },
            {
                "dict_id": 2,
                "dict_name": "two",
                "sub_dict": {
                    "sub_dict_id": 2.1,
                    "sub_dict_name": "two point one"
                },
                "sub_list": [
                    "d",
                    "e",
                    "f"
                ]
            }
        ],
        "list_2": [
            {
                "dict_id": 3,
                "dict_name": "three",
                "sub_dict": {
                    "sub_dict_id": 3.1,
                    "sub_dict_name": "three point one"
                },
                "sub_list": [
                    "g",
                    "h",
                    "i"
                ]
            },
            {
                "dict_id": 4,
                "dict_name": "four",
                "sub_dict": {
                    "sub_dict_id": 4.1,
                    "sub_dict_name": "four point one"
                },
                "sub_list": [
                    "j",
                    "k",
                    "l"
                ]
            }
        ]
    }
    """


# ---------------
# Tests
# ---------------


def test_all_types(dict_with_all_types):
    """Test loading a simple dict all data types."""

    assert json.loads(dict_with_all_types)

    stream = adafruit_json_stream.load(BytesChunkIO(dict_with_all_types.encode()))

    assert stream["bool"] is True
    assert stream["dict"]["key"] == "value"
    assert stream["float"] == 1.1
    assert stream["int"] == 1
    assert next(stream["list"]) == 1
    assert stream["null"] is None
    assert stream["string"] == "string"


def test_simple_dict_with_keys(dict_with_keys):
    """Test loading a simple dict with keys."""

    assert json.loads(dict_with_keys)

    stream = adafruit_json_stream.load(BytesChunkIO(dict_with_keys.encode()))
    for i in range(1, 4):
        assert stream[f"field_{i}"] == i
    with pytest.raises(KeyError, match="field_4"):
        stream["field_4"]


def test_simple_dict_with_grabbing_key_twice_raises(dict_with_keys):
    """Test loading a simple dict with keys twice raises."""

    assert json.loads(dict_with_keys)

    stream = adafruit_json_stream.load(BytesChunkIO(dict_with_keys.encode()))
    assert stream["field_1"] == 1
    with pytest.raises(KeyError, match="field_1"):
        stream["field_1"]


def test_simple_dict_with_keys_middle_key(dict_with_keys):
    """Test loading a simple dict and grabbing a key in the middle."""

    assert json.loads(dict_with_keys)

    stream = adafruit_json_stream.load(BytesChunkIO(dict_with_keys.encode()))
    assert stream["field_2"] == 2


def test_simple_dict_with_keys_missing_key_raises(dict_with_keys):
    """Test loading a simple dict and grabbing a key that doesn't exist raises."""

    assert json.loads(dict_with_keys)

    stream = adafruit_json_stream.load(BytesChunkIO(dict_with_keys.encode()))
    with pytest.raises(KeyError, match="field_4"):
        stream["field_4"]


def test_list_with_values(list_with_values):
    """Test loading a list and iterating over it."""

    assert json.loads(list_with_values)

    stream = adafruit_json_stream.load(BytesChunkIO(list_with_values.encode()))
    counter = 0
    for value in stream:
        counter += 1
        assert value == counter


def test_dict_with_list_of_single_entries(dict_with_list_with_single_entries):
    """Test loading an dict with a list of dicts with one entry each."""

    assert json.loads(dict_with_list_with_single_entries)

    stream = adafruit_json_stream.load(
        BytesChunkIO(dict_with_list_with_single_entries.encode())
    )
    counter = 0
    for obj in stream["list_1"]:
        counter += 1
        assert obj["dict_id"] == counter
    assert counter == 4


def test_complex_dict(complex_dict):
    """Test loading a complex dict."""

    assert json.loads(complex_dict)

    dict_names = [
        "one",
        "two",
        "three",
        "four",
    ]

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))
    counter = 0
    sub_counter = 0
    for obj in stream["list_1"]:
        counter += 1
        assert obj["dict_id"] == counter
        assert obj["dict_name"] == dict_names[counter - 1]
        sub_dict = obj["sub_dict"]
        assert sub_dict["sub_dict_id"] == counter + 0.1
        assert sub_dict["sub_dict_name"] == f"{dict_names[counter-1]} point one"
        for item in obj["sub_list"]:
            sub_counter += 1
            assert item == chr(96 + sub_counter)

    assert counter == 2
    assert sub_counter == 6

    for obj in stream["list_2"]:
        counter += 1
        assert obj["dict_id"] == counter
        assert obj["dict_name"] == dict_names[counter - 1]
        sub_dict = obj["sub_dict"]
        assert sub_dict["sub_dict_id"] == counter + 0.1
        assert sub_dict["sub_dict_name"] == f"{dict_names[counter-1]} point one"
        for item in obj["sub_list"]:
            sub_counter += 1
            assert item == chr(96 + sub_counter)

    assert counter == 4
    assert sub_counter == 12


def test_complex_dict_grabbing(complex_dict):
    """Test loading a complex dict and grabbing specific keys."""

    assert json.loads(complex_dict)

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    sub_list = dict_1["sub_list"]
    assert next(sub_list) == "a"
    list_2 = stream["list_2"]
    next(list_2)
    dict_2 = next(list_2)
    sub_list = dict_2["sub_list"]
    assert next(sub_list) == "j"


def test_complex_dict_passed_key_raises(complex_dict):
    """
    Test loading a complex dict and attempting to grab a specific key that has been passed raises.
    """

    assert json.loads(complex_dict)

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    assert dict_1["dict_name"] == "one"
    with pytest.raises(KeyError, match="obects_id"):
        stream["obects_id"]


def test_complex_dict_passed_reference_raises(complex_dict):
    """
    Test loading a complex dict and attempting to grab a data from a saved reference that has
    been passed raises.
    """

    assert json.loads(complex_dict)

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    sub_dict = dict_1["sub_dict"]
    sub_list = dict_1["sub_list"]
    list_2 = stream["list_2"]
    next(list_2)
    with pytest.raises(KeyError, match="sub_dict_id"):
        sub_dict["sub_dict_id"]
    with pytest.raises(StopIteration):
        next(sub_list)


# complex_dict is 1518 bytes
@pytest.mark.parametrize(
    ("chunk_size", "expected_chunks"), ((10, 152), (50, 31), (100, 16), (5000, 1))
)
def test_complex_dict_buffer_sizes(chunk_size, complex_dict, expected_chunks):
    """Test loading a complex dict and checking the chunking."""

    assert json.loads(complex_dict)

    bytes_io_chunk = BytesChunkIO(complex_dict.encode(), chunk_size)

    stream = adafruit_json_stream.load(bytes_io_chunk)

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    sub_list = dict_1["sub_list"]
    assert next(sub_list) == "a"
    list_2 = stream["list_2"]
    next(list_2)
    dict_2 = next(list_2)
    sub_list = dict_2["sub_list"]
    assert next(sub_list) == "j"
    for _ in sub_list:
        pass
    with pytest.raises(KeyError):
        stream["list_3"]

    assert bytes_io_chunk.get_chunks_read() == expected_chunks
    assert math.ceil(len(complex_dict) / chunk_size) == expected_chunks


# complex_dict is 1518 bytes
@pytest.mark.parametrize(
    ("chunk_size", "expected_chunks"), ((5, 61), (10, 31), (50, 7), (100, 4))
)
def test_complex_dict_not_looking_at_all_data_buffer_sizes(
    chunk_size, complex_dict, expected_chunks
):
    """Test loading a complex dict and checking the chunking."""

    assert json.loads(complex_dict)

    bytes_io_chunk = BytesChunkIO(complex_dict.encode(), chunk_size)

    stream = adafruit_json_stream.load(bytes_io_chunk)

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    sub_list = dict_1["sub_list"]
    assert next(sub_list) == "a"

    assert bytes_io_chunk.get_chunks_read() == expected_chunks
    assert math.ceil(len(complex_dict) / chunk_size) >= (expected_chunks / 4)


def test_incomplete_json_raises():
    """Test incomplete json raises."""

    data = """
    {
        "field_1": 1
    """

    with pytest.raises(json.JSONDecodeError):
        json.loads(data)

    stream = adafruit_json_stream.load(BytesChunkIO(data.encode()))

    with pytest.raises(EOFError):
        stream["field_2"]


def test_as_object(complex_dict):
    """Test loading a complex dict and grabbing parts as objects."""

    assert json.loads(complex_dict)

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    assert dict_1["sub_dict"].as_object() == {
        "sub_dict_id": 1.1,
        "sub_dict_name": "one point one",
    }
    assert dict_1["sub_list"].as_object() == ["a", "b", "c"]
    dict_2 = next(list_1)
    assert dict_2.as_object() == {
        "dict_id": 2,
        "dict_name": "two",
        "sub_dict": {"sub_dict_id": 2.1, "sub_dict_name": "two point one"},
        "sub_list": ["d", "e", "f"],
    }
    assert stream["list_2"].as_object() == [
        {
            "dict_id": 3,
            "dict_name": "three",
            "sub_dict": {"sub_dict_id": 3.1, "sub_dict_name": "three point one"},
            "sub_list": ["g", "h", "i"],
        },
        {
            "dict_id": 4,
            "dict_name": "four",
            "sub_dict": {"sub_dict_id": 4.1, "sub_dict_name": "four point one"},
            "sub_list": ["j", "k", "l"],
        },
    ]


def test_as_object_stream(dict_with_all_types):

    assert json.loads(dict_with_all_types)

    stream = adafruit_json_stream.load(BytesChunkIO(dict_with_all_types.encode()))

    obj = stream.as_object()
    assert obj == {
        "_check": '{"a": 1, "b": [2,3]}',
        "bool": True,
        "dict": {"key": "value"},
        "float": 1.1,
        "int": 1,
        "list": [1, 2, 3],
        "null": None,
        "string": "string",
    }
    assert json.loads(obj["_check"]) == {
        "a": 1,
        "b": [
            2,
            3,
        ],
    }


def test_as_object_that_is_partially_read_raises(complex_dict):
    """Test loading a complex dict and grabbing partially read raises."""

    assert json.loads(complex_dict)

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    assert dict_1["dict_id"] == 1
    with pytest.raises(BufferError):
        dict_1.as_object()


def test_as_object_grabbing_multiple_subscriptable_levels_twice(complex_dict):
    """Test loading a complex dict and grabbing multiple subscriptable levels twice."""

    assert json.loads(complex_dict)

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    assert dict_1["sub_dict"]["sub_dict_id"] == 1.1
    assert dict_1["sub_dict"]["sub_dict_name"] == "one point one"


def test_as_object_grabbing_multiple_subscriptable_levels_again_after_passed_raises(
    complex_dict,
):
    """
    Test loading a complex dict and grabbing multiple subscriptable levels after passing it raises.
    """

    assert json.loads(complex_dict)

    stream = adafruit_json_stream.load(BytesChunkIO(complex_dict.encode()))

    list_1 = stream["list_1"]
    dict_1 = next(list_1)
    assert dict_1["sub_dict"]["sub_dict_id"] == 1.1
    assert next(dict_1["sub_list"]) == "a"
    with pytest.raises(KeyError, match="sub_dict"):
        dict_1["sub_dict"]["sub_dict_name"]