Add test coverage and docstrings for counters module (#31)

Co-authored-by: s3rius <18153319+s3rius@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Pavel Kirilin <win10@list.ru>

Author: Copilot

python/natsrpy/_natsrpy_rs/js/counters.pyi

@@ -155,31 +155,89 @@ class CountersConfig:
 
 @final
 class CounterEntry:
+    """A single counter entry retrieved from a counters stream.
+
+    Holds the current aggregated value for a counter subject along
+    with metadata about cross-stream sources and the last increment.
+
+    Attributes:
+        subject: the subject this counter entry belongs to.
+        value: the current aggregated counter value.
+        sources: mapping of source stream names to their per-subject
+            counter contributions.
+        increment: the value of the last increment applied, or ``None``
+            when the entry was retrieved via ``Counters.get``.
+    """
+
     subject: str
     value: int
     sources: dict[str, dict[str, int]]
     increment: int | None
 
 @final
 class Counters:
+    """Handle for a JetStream counters stream.
+
+    Provides atomic increment, decrement, and retrieval operations
+    on CRDT counters backed by a JetStream stream with
+    ``allow_message_counter`` enabled.
+    """
+
     async def add(
         self,
         key: str,
         value: int,
         timeout: float | timedelta | None = None,
-    ) -> int: ...
+    ) -> int:
+        """Add an arbitrary value to a counter.
+
+        :param key: subject key identifying the counter.
+        :param value: integer amount to add (may be negative).
+        :param timeout: optional operation timeout in seconds or as
+            a timedelta.
+        :return: the new counter value after the addition.
+        """
+
     async def incr(
         self,
         key: str,
         timeout: float | timedelta | None = None,
-    ) -> int: ...
+    ) -> int:
+        """Increment a counter by one.
+
+        Shorthand for ``add(key, 1)``.
+
+        :param key: subject key identifying the counter.
+        :param timeout: optional operation timeout in seconds or as
+            a timedelta.
+        :return: the new counter value after the increment.
+        """
+
     async def decr(
         self,
         key: str,
         timeout: float | timedelta | None = None,
-    ) -> int: ...
+    ) -> int:
+        """Decrement a counter by one.
+
+        Shorthand for ``add(key, -1)``.
+
+        :param key: subject key identifying the counter.
+        :param timeout: optional operation timeout in seconds or as
+            a timedelta.
+        :return: the new counter value after the decrement.
+        """
+
     async def get(
         self,
         key: str,
         timeout: float | timedelta | None = None,
-    ) -> CounterEntry: ...
+    ) -> CounterEntry:
+        """Retrieve the current value of a counter.
+
+        :param key: subject key identifying the counter.
+        :param timeout: optional operation timeout in seconds or as
+            a timedelta.
+        :return: counter entry with the current value and metadata.
+        :raises Exception: if no counter entry exists for the key.
+        """

python/tests/test_counters.py

@@ -0,0 +1,225 @@
+import uuid
+
+import pytest
+from natsrpy.js import CounterEntry, Counters, CountersConfig, JetStream
+
+
+async def test_counters_create(js: JetStream) -> None:
+    name = f"test-cnt-create-{uuid.uuid4().hex[:8]}"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        assert isinstance(counters, Counters)
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_create_or_update(js: JetStream) -> None:
+    name = f"test-cnt-cou-{uuid.uuid4().hex[:8]}"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create_or_update(config)
+    try:
+        assert isinstance(counters, Counters)
+        config.description = "updated"
+        counters2 = await js.counters.create_or_update(config)
+        assert isinstance(counters2, Counters)
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_get(js: JetStream) -> None:
+    name = f"test-cnt-get-{uuid.uuid4().hex[:8]}"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    await js.counters.create(config)
+    try:
+        counters = await js.counters.get(name)
+        assert isinstance(counters, Counters)
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_delete(js: JetStream) -> None:
+    name = f"test-cnt-del-{uuid.uuid4().hex[:8]}"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    await js.counters.create(config)
+    result = await js.counters.delete(name)
+    assert result is True
+
+
+async def test_counters_update(js: JetStream) -> None:
+    name = f"test-cnt-upd-{uuid.uuid4().hex[:8]}"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    await js.counters.create(config)
+    try:
+        update_cfg = CountersConfig(
+            name=name,
+            subjects=[f"{name}.>"],
+            description="updated description",
+        )
+        counters = await js.counters.update(update_cfg)
+        assert isinstance(counters, Counters)
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_incr(js: JetStream) -> None:
+    name = f"test-cnt-incr-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        value = await counters.incr(subj)
+        assert value == 1
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_decr(js: JetStream) -> None:
+    name = f"test-cnt-decr-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        value = await counters.decr(subj)
+        assert value == -1
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_add(js: JetStream) -> None:
+    name = f"test-cnt-add-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        value = await counters.add(subj, 10)
+        assert value == 10
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_add_negative(js: JetStream) -> None:
+    name = f"test-cnt-addneg-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        value = await counters.add(subj, -5)
+        assert value == -5
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_get_entry(js: JetStream) -> None:
+    name = f"test-cnt-gete-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        await counters.incr(subj)
+        entry = await counters.get(subj)
+        assert isinstance(entry, CounterEntry)
+        assert entry.subject == subj
+        assert entry.value == 1
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counter_entry_attributes(js: JetStream) -> None:
+    name = f"test-cnt-attr-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        await counters.add(subj, 5)
+        entry = await counters.get(subj)
+        assert isinstance(entry.subject, str)
+        assert isinstance(entry.value, int)
+        assert isinstance(entry.sources, dict)
+        assert entry.increment is None or isinstance(entry.increment, int)
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_multiple_increments(js: JetStream) -> None:
+    name = f"test-cnt-multi-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        val1 = await counters.incr(subj)
+        val2 = await counters.incr(subj)
+        val3 = await counters.incr(subj)
+        assert val1 == 1
+        assert val2 == 2
+        assert val3 == 3
+        entry = await counters.get(subj)
+        assert entry.value == 3
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_incr_then_decr(js: JetStream) -> None:
+    name = f"test-cnt-incdec-{uuid.uuid4().hex[:8]}"
+    subj = f"{name}.hits"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        await counters.incr(subj)
+        await counters.incr(subj)
+        await counters.decr(subj)
+        entry = await counters.get(subj)
+        assert entry.value == 1
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_separate_subjects(js: JetStream) -> None:
+    name = f"test-cnt-sep-{uuid.uuid4().hex[:8]}"
+    subj_a = f"{name}.a"
+    subj_b = f"{name}.b"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        await counters.add(subj_a, 10)
+        await counters.add(subj_b, 20)
+        entry_a = await counters.get(subj_a)
+        entry_b = await counters.get(subj_b)
+        assert entry_a.value == 10
+        assert entry_b.value == 20
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_get_nonexistent_key(js: JetStream) -> None:
+    name = f"test-cnt-nokey-{uuid.uuid4().hex[:8]}"
+    config = CountersConfig(name=name, subjects=[f"{name}.>"])
+    counters = await js.counters.create(config)
+    try:
+        with pytest.raises(Exception):
+            await counters.get(f"{name}.nonexistent")
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_config_description(js: JetStream) -> None:
+    name = f"test-cnt-desc-{uuid.uuid4().hex[:8]}"
+    config = CountersConfig(
+        name=name,
+        subjects=[f"{name}.>"],
+        description="A test counters stream",
+    )
+    counters = await js.counters.create(config)
+    try:
+        assert isinstance(counters, Counters)
+    finally:
+        await js.counters.delete(name)
+
+
+async def test_counters_config_defaults() -> None:
+    config = CountersConfig(name="test", subjects=["test.>"])
+    assert config.name == "test"
+    assert config.subjects == ["test.>"]
+    assert config.description is None
+    assert config.max_bytes is not None
+    assert config.max_messages is not None

src/js/managers/counters.rs

@@ -7,7 +7,7 @@ use crate::{
 use pyo3::{Bound, PyAny, Python};
 use tokio::sync::RwLock;
 
-use crate::{exceptions::rust_err::NatsrpyResult, js::stream::StreamConfig, utils::natsrpy_future};
+use crate::{exceptions::rust_err::NatsrpyResult, utils::natsrpy_future};
 
 #[pyo3::pyclass]
 pub struct CountersManager {
@@ -87,7 +87,7 @@ impl CountersManager {
     pub fn update<'py>(
         &self,
         py: Python<'py>,
-        config: StreamConfig,
+        config: CountersConfig,
     ) -> NatsrpyResult<Bound<'py, PyAny>> {
         let ctx = self.ctx.clone();
         natsrpy_future(py, async move {