Fix equality for AbstractBufferedFile != b'' (#1594)

Co-authored-by: Martin Durant <martin.durant@alumni.utoronto.ca>

fsspec/spec.py

@@ -1698,7 +1698,12 @@ def __eq__(self, other):
         """Files are equal if they have the same checksum, only in read mode"""
         if self is other:
             return True
-        return self.mode == "rb" and other.mode == "rb" and hash(self) == hash(other)
+        return (
+            isinstance(other, type(self))
+            and self.mode == "rb"
+            and other.mode == "rb"
+            and hash(self) == hash(other)
+        )
 
     def commit(self):
         """Move from temp to final destination"""

fsspec/tests/test_spec.py

@@ -819,6 +819,10 @@ def test_eq():
     result = fs == 1
     assert result is False
 
+    f = AbstractBufferedFile(fs, "misc/foo.txt", cache_type="bytes")
+    result = f == 1
+    assert result is False
+
 
 def test_pickle_multiple():
     a = DummyTestFS(1)