1 files changed, 45 insertions, 0 deletions
diff --git a/tests/adapters_example.py b/tests/adapters_example.py
new file mode 100644
index 0000000..a184e6a
--- /dev/null
+++ b/tests/adapters_example.py
@@ -0,0 +1,45 @@
+from typing import Optional
+
+from psycopg import pq
+from psycopg.abc import Dumper, Loader, AdaptContext, PyFormat, Buffer
+
+
+def f() -> None:
+    d: Dumper = MyStrDumper(str, None)
+    assert d.dump("abc") == b"abcabc"
+    assert d.quote("abc") == b"'abcabc'"
+
+    lo: Loader = MyTextLoader(0, None)
+    assert lo.load(b"abc") == "abcabc"
+
+
+class MyStrDumper:
+    format = pq.Format.TEXT
+    oid = 25  # text
+
+    def __init__(self, cls: type, context: Optional[AdaptContext] = None):
+        self._cls = cls
+
+    def dump(self, obj: str) -> bytes:
+        return (obj * 2).encode()
+
+    def quote(self, obj: str) -> bytes:
+        value = self.dump(obj)
+        esc = pq.Escaping()
+        return b"'%s'" % esc.escape_string(value.replace(b"h", b"q"))
+
+    def get_key(self, obj: str, format: PyFormat) -> type:
+        return self._cls
+
+    def upgrade(self, obj: str, format: PyFormat) -> "MyStrDumper":
+        return self
+
+
+class MyTextLoader:
+    format = pq.Format.TEXT
+
+    def __init__(self, oid: int, context: Optional[AdaptContext] = None):
+        pass
+
+    def load(self, data: Buffer) -> str:
+        return (bytes(data) * 2).decode()