EntityRuler improve disk load error message

spacy/errors.py

@@ -887,6 +887,7 @@ class Errors(metaclass=ErrorsWithCodes):
     E1021 = ("`pos` value \"{pp}\" is not a valid Universal Dependencies tag. "
              "Non-UD tags should use the `tag` property.")
     E1022 = ("Words must be of type str or int, but input is of type '{wtype}'")
+    E1023 = ("Couldn't read EntityRuler from the {path}. This file doesn't exist.")
 
 
 # Deprecated model shortcuts, only used in errors and warnings

spacy/pipeline/entityruler.py

@@ -431,10 +431,16 @@ def from_disk(
         path = ensure_path(path)
         self.clear()
         depr_patterns_path = path.with_suffix(".jsonl")
-        if depr_patterns_path.is_file():
+        if path.suffix == ".jsonl":  # user provides a jsonl
+            if path.is_file:
+                patterns = srsly.read_jsonl(path)
+                self.add_patterns(patterns)
+            else:
+                raise ValueError(Errors.E1023.format(path=path))
+        elif depr_patterns_path.is_file():
             patterns = srsly.read_jsonl(depr_patterns_path)
             self.add_patterns(patterns)
-        else:
+        elif path.is_dir():  # path is a valid directory
             cfg = {}
             deserializers_patterns = {
                 "patterns": lambda p: self.add_patterns(
@@ -451,6 +457,8 @@ def from_disk(
                 self.nlp.vocab, attr=self.phrase_matcher_attr
             )
             from_disk(path, deserializers_patterns, {})
+        else:  # path is not a valid directory or file
+            raise ValueError(Errors.E146.format(path=path))
         return self
 
     def to_disk(

spacy/tests/pipeline/test_entity_ruler.py

@@ -5,6 +5,8 @@
 from spacy.language import Language
 from spacy.pipeline import EntityRuler
 from spacy.errors import MatchPatternError
+from spacy.tests.util import make_tempdir
+
 from thinc.api import NumpyOps, get_current_ops
 
 
@@ -238,3 +240,23 @@ def test_entity_ruler_multiprocessing(nlp, n_process):
         for doc in nlp.pipe(texts, n_process=2):
             for ent in doc.ents:
                 assert ent.ent_id_ == "1234"
+
+
+def test_entity_ruler_serialize_jsonl(nlp, patterns):
+    ruler = nlp.add_pipe("entity_ruler")
+    ruler.add_patterns(patterns)
+    with make_tempdir() as d:
+        ruler.to_disk(d / "test_ruler.jsonl")
+        ruler.from_disk(d / "test_ruler.jsonl")  # read from an existing jsonl file
+        with pytest.raises(ValueError):
+            ruler.from_disk(d / "non_existing.jsonl")  # read from an bad jsonl file
+
+
+def test_entity_ruler_serialize_dir(nlp, patterns):
+    ruler = nlp.add_pipe("entity_ruler")
+    ruler.add_patterns(patterns)
+    with make_tempdir() as d:
+        ruler.to_disk(d / "test_ruler")
+        ruler.from_disk(d / "test_ruler")  # read from an existing directory
+        with pytest.raises(ValueError):
+            ruler.from_disk(d / "non_existing_dir")  # read from a bad directory