fixup! make max_statements=0 mean no limit

src/ralph/backends/data/async_es.py

@@ -134,7 +134,7 @@ async def read(  # noqa: PLR0913
             prefetch (int): The number of records to prefetch (queue) while yielding.
                 If `prefetch` is `None` it defaults to `1` - no records are prefetched.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             bytes: The next raw document if `raw_output` is True.

src/ralph/backends/data/async_mongo.py

@@ -141,7 +141,7 @@ async def read(  # noqa: PLR0913
             prefetch (int): The number of records to prefetch (queue) while yielding.
                 If `prefetch` is `None` it defaults to `1` - no records are prefetched.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             bytes: The next raw document if `raw_output` is True.

src/ralph/backends/data/base.py

@@ -300,7 +300,7 @@ def read(  # noqa: PLR0913
                 will be ignored and logged.
                 If `False` (default), a `BackendException` is raised on any error.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             dict: If `raw_output` is False.
@@ -315,11 +315,8 @@ def read(  # noqa: PLR0913
         query = validate_backend_query(query, self.query_class, self.logger)
         reader = self._read_bytes if raw_output else self._read_dicts
         statements = reader(query, target, chunk_size, ignore_errors)
-        if max_statements is None:
-            yield from statements
-            return
-
         if not max_statements:
+            yield from statements
             return
 
         max_statements -= 1
@@ -535,7 +532,7 @@ async def read(  # noqa: PLR0913
             prefetch (int): The number of records to prefetch (queue) while yielding.
                 If `prefetch` is `None` it defaults to `1` - no records are prefetched.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             dict: If `raw_output` is False.
@@ -579,14 +576,11 @@ async def read(  # noqa: PLR0913
         query = validate_backend_query(query, self.query_class, self.logger)
         reader = self._read_bytes if raw_output else self._read_dicts
         statements = reader(query, target, chunk_size, ignore_errors)
-        if max_statements is None:
+        if not max_statements:
             async for statement in statements:
                 yield statement
             return
 
-        if not max_statements:
-            return
-
         i = 0
         async for statement in statements:
             yield statement

src/ralph/backends/data/clickhouse.py

@@ -226,7 +226,7 @@ def read(  # noqa: PLR0913
                 will be ignored and logged.
                 If `False` (default), a `BackendException` is raised on any error.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             bytes: The next raw document if `raw_output` is True.

src/ralph/backends/data/es.py

@@ -215,7 +215,7 @@ def read(  # noqa: PLR0913
             ignore_errors (bool): No impact as encoding errors are not expected in
                 Elasticsearch results.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             bytes: The next raw document if `raw_output` is True.

src/ralph/backends/data/fs.py

@@ -172,7 +172,7 @@ def read(  # noqa: PLR0913
                 will be ignored and logged.
                 If `False` (default), a `BackendException` is raised on any error.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             bytes: The next chunk of the read files if `raw_output` is True.

src/ralph/backends/data/ldp.py

@@ -170,7 +170,7 @@ def read(  # noqa: PLR0913
             raw_output (bool): Should always be set to `True`.
             ignore_errors (bool): No impact as no encoding operation is performed.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             bytes: The content of the archive matching the query.

src/ralph/backends/data/mongo.py

@@ -193,7 +193,7 @@ def read(  # noqa: PLR0913
                 will be ignored and logged.
                 If `False` (default), a `BackendException` is raised on any error.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             dict: If `raw_output` is False.

src/ralph/backends/data/s3.py

@@ -186,7 +186,7 @@ def read(  # noqa: PLR0913
                 will be ignored and logged.
                 If `False` (default), a `BackendException` is raised on any error.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             dict: If `raw_output` is False.

src/ralph/backends/data/swift.py

@@ -200,7 +200,7 @@ def read(  # noqa: PLR0913
                 will be ignored and logged.
                 If `False` (default), a `BackendException` is raised on any error.
             max_statements (int): The maximum number of statements to yield.
-                If `None` (default), there is no maximum.
+                If `None` (default) or `0`, there is no maximum.
 
         Yield:
             dict: If `raw_output` is False.

tests/backends/data/test_base.py

@@ -147,17 +147,16 @@ def close(self):
 
     backend = MockBaseDataBackend()
     assert list(backend.read()) == [{}, {}, {}, {}]
+    assert list(backend.read(max_statements=0)) == [{}, {}, {}, {}]
     assert list(backend.read(raw_output=True)) == [b"", b"", b""]
+    assert list(backend.read(max_statements=0, raw_output=True)) == [b"", b"", b""]
 
     assert list(backend.read(max_statements=9)) == [{}, {}, {}, {}]
     assert list(backend.read(max_statements=9, raw_output=True)) == [b"", b"", b""]
 
     assert list(backend.read(max_statements=3)) == [{}, {}, {}]
     assert list(backend.read(max_statements=3, raw_output=True)) == [b"", b"", b""]
 
-    assert not list(backend.read(max_statements=0))
-    assert not list(backend.read(max_statements=0, raw_output=True))
-
 
 @pytest.mark.anyio
 @pytest.mark.parametrize(
@@ -311,7 +310,13 @@ async def close(self):
 
     backend = MockAsyncBaseDataBackend()
     assert [_ async for _ in backend.read()] == [{}, {}, {}, {}]
+    assert [_ async for _ in backend.read(max_statements=0)] == [{}, {}, {}, {}]
     assert [_ async for _ in backend.read(raw_output=True)] == [b"", b"", b""]
+    assert [_ async for _ in backend.read(max_statements=0, raw_output=True)] == [
+        b"",
+        b"",
+        b"",
+    ]
 
     assert [_ async for _ in backend.read(max_statements=9)] == [{}, {}, {}, {}]
     assert [_ async for _ in backend.read(max_statements=9, raw_output=True)] == [
@@ -327,9 +332,6 @@ async def close(self):
         b"",
     ]
 
-    assert not [_ async for _ in backend.read(max_statements=0)]
-    assert not [_ async for _ in backend.read(max_statements=0, raw_output=True)]
-
 
 @pytest.mark.anyio
 @pytest.mark.parametrize(