safer get_hints handling

Failsafe approach to Hints usage: only fail on missing or non-dict-like values.
Assume, `hints=` can be whatever and
 - only cherry-pick our expected Hint from there
 - cast any value to bool

While this drifts a bit appart the zero-logic approach of the wrapper, it's a common
pythonic approach for this kind of things.
Main reason for this is that filtering and casting in Python allows exception to
go up the stack while in-cpp casting does not and ends up ignored.

Now testing:
 - Item without `get_hints()`
 - writer.Item without `get_hints()` impl.
 - `get_hints()` returning a non-dict value
 - `get_hints()` returning unexpected hints (filtered)
 - hints on redirection

Author: renaud gaudin

libzim/wrapper.pyx

@@ -40,7 +40,7 @@ import datetime
 import traceback
 
 
-
+pybool = type(True)
 
 #########################
 #         Blob          #
@@ -179,8 +179,8 @@ cdef public api:
         cdef map[HintKeys, uint64_t] ret;
         try:
             func = getattr(obj, method.decode('UTF-8'))
-            hintsDict = func()
-            return convertToCppHints(func())
+            hintsDict = {k: pybool(v) for k, v in func().items() if isinstance(k, Hint)}
+            return convertToCppHints(hintsDict)
         except Exception as e:
             error[0] = traceback.format_exc().encode('UTF-8')
 

libzim/writer.py

@@ -134,7 +134,7 @@ def get_contentprovider(self) -> ContentProvider:
         raise NotImplementedError("get_contentprovider must be implemented.")
 
     def get_hints(self) -> Dict[Hint, int]:
-        raise NotImplementedError("get_hint must be implemenent")
+        raise NotImplementedError("get_hints must be implemented.")
 
     def __repr__(self) -> str:
         return (

tests/test_libzim_creator.py

@@ -47,7 +47,7 @@ def get_contentprovider(self) -> libzim.writer.ContentProvider:
         return StringProvider(content=getattr(self, "content", ""))
 
     def get_hints(self) -> Dict[Hint, int]:
-        return {Hint.FRONT_ARTICLE: True}
+        return getattr(self, "hints", {Hint.FRONT_ARTICLE: True})
 
 
 @pytest.fixture(scope="function")
@@ -555,6 +555,76 @@ def get_hints(self):
             c.add_item(AnItem())
 
 
+def test_missing_hints(fpath):
+    class AnItem:
+        def get_path(self):
+            return ""
+
+        def get_title(self):
+            return ""
+
+        def get_mimetype(self):
+            return ""
+
+    with Creator(fpath) as c:
+        with pytest.raises(RuntimeError, match="has no attribute"):
+            c.add_item(AnItem())
+
+        with pytest.raises(RuntimeError, match="must be implemented"):
+            c.add_item(libzim.writer.Item())
+
+
+def test_nondict_hints(fpath):
+    class AnItem:
+        def get_path(self):
+            return ""
+
+        def get_title(self):
+            return ""
+
+        def get_mimetype(self):
+            return ""
+
+    with Creator(fpath) as c:
+        with pytest.raises(RuntimeError, match="has no attribute 'get_hints'"):
+            c.add_item(AnItem())
+
+        with pytest.raises(RuntimeError, match="has no attribute 'items'"):
+            c.add_item(StaticItem(path="1", title="", hints=1))
+
+        with pytest.raises(TypeError, match="hints"):
+            c.add_redirection("a", "", "b", hints=1)
+
+
+def test_hints_values(fpath):
+    with Creator(fpath) as c:
+        # correct values
+        c.add_item(StaticItem(path="0", title="", hints={}))
+        c.add_item(
+            StaticItem(
+                path="1",
+                title="",
+                hints={Hint.FRONT_ARTICLE: True, Hint.COMPRESS: False},
+            )
+        )
+        # non-expected Hints are ignored
+        c.add_item(StaticItem(path="2", title="", hints={"hello": "world"}))
+        # Hint values are casted to bool
+        c.add_item(StaticItem(path="3", title="", hints={Hint.FRONT_ARTICLE: "world"}))
+        c.add_redirection(
+            path="4", title="", targetPath="0", hints={Hint.COMPRESS: True}
+        )
+
+        # non-existent Hint
+        with pytest.raises(AttributeError, match="YOLO"):
+            c.add_item(StaticItem(path="0", title="", hints={Hint.YOLO: True}))
+
+        with pytest.raises(AttributeError, match="YOLO"):
+            c.add_redirection(
+                path="5", title="", target_path="0", hints={Hint.YOLO: True}
+            )
+
+
 def test_reimpfeed(fpath):
     class AContentProvider:
         def __init__(self):