From 9fa79bb53638e02aaa45d77397b39a1b652ba5f1 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 2 Nov 2021 18:19:35 -0400
Subject: [PATCH] map Float to asyncpg.FLOAT, test for infinity

Fixes: #7283
Change-Id: I5402a72617b7f9bc366d64bc5ce8669374839984
---
 doc/build/changelog/unreleased_14/7283.rst    |  9 +++++++++
 lib/sqlalchemy/dialects/postgresql/asyncpg.py |  9 +++++++++
 lib/sqlalchemy/testing/requirements.py        |  6 ++++++
 lib/sqlalchemy/testing/suite/test_types.py    | 10 ++++++++++
 test/requirements.py                          |  8 ++++++++
 5 files changed, 42 insertions(+)
 create mode 100644 doc/build/changelog/unreleased_14/7283.rst

diff --git a/doc/build/changelog/unreleased_14/7283.rst b/doc/build/changelog/unreleased_14/7283.rst
new file mode 100644
index 0000000000..0cfd2a491e
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/7283.rst
@@ -0,0 +1,9 @@
+.. change::
+    :tags: bug, postgresql
+    :tickets: 7283
+
+    Changed the asyncpg dialect to bind the :class:`.Float` type to the "float"
+    PostgreSQL type instead of "numeric" so that the value ``float(inf)`` can
+    be accommodated. Added test suite support for persisence of the "inf"
+    value.
+
diff --git a/lib/sqlalchemy/dialects/postgresql/asyncpg.py b/lib/sqlalchemy/dialects/postgresql/asyncpg.py
index 3d195e691a..913b931597 100644
--- a/lib/sqlalchemy/dialects/postgresql/asyncpg.py
+++ b/lib/sqlalchemy/dialects/postgresql/asyncpg.py
@@ -249,6 +249,9 @@ class AsyncpgUUID(UUID):
 
 
 class AsyncpgNumeric(sqltypes.Numeric):
+    def get_dbapi_type(self, dbapi):
+        return dbapi.NUMBER
+
     def bind_processor(self, dialect):
         return None
 
@@ -277,6 +280,11 @@ class AsyncpgNumeric(sqltypes.Numeric):
                 )
 
 
+class AsyncpgFloat(AsyncpgNumeric):
+    def get_dbapi_type(self, dbapi):
+        return dbapi.FLOAT
+
+
 class AsyncpgREGCLASS(REGCLASS):
     def get_dbapi_type(self, dbapi):
         return dbapi.STRING
@@ -883,6 +891,7 @@ class PGDialect_asyncpg(PGDialect):
             sqltypes.Integer: AsyncpgInteger,
             sqltypes.BigInteger: AsyncpgBigInteger,
             sqltypes.Numeric: AsyncpgNumeric,
+            sqltypes.Float: AsyncpgFloat,
             sqltypes.JSON: AsyncpgJSON,
             json.JSONB: AsyncpgJSONB,
             sqltypes.JSON.JSONPathType: AsyncpgJSONPathType,
diff --git a/lib/sqlalchemy/testing/requirements.py b/lib/sqlalchemy/testing/requirements.py
index 8b385b5d2d..08acbd2d2d 100644
--- a/lib/sqlalchemy/testing/requirements.py
+++ b/lib/sqlalchemy/testing/requirements.py
@@ -980,6 +980,12 @@ class SuiteRequirements(Requirements):
 
         return exclusions.closed()
 
+    @property
+    def infinity_floats(self):
+        """The Float type can persist and load float('inf'), float('-inf')."""
+
+        return exclusions.closed()
+
     @property
     def precision_generic_float_type(self):
         """target backend will return native floating point numbers with at
diff --git a/lib/sqlalchemy/testing/suite/test_types.py b/lib/sqlalchemy/testing/suite/test_types.py
index 93d37d4d50..7438b8bc89 100644
--- a/lib/sqlalchemy/testing/suite/test_types.py
+++ b/lib/sqlalchemy/testing/suite/test_types.py
@@ -590,6 +590,16 @@ class NumericTest(_LiteralRoundTripFixture, fixtures.TestBase):
             [15.7563],
         )
 
+    @testing.requires.infinity_floats
+    def test_infinity_floats(self, do_numeric_test):
+        """test for #977, #7283"""
+
+        do_numeric_test(
+            Float(None),
+            [float("inf")],
+            [float("inf")],
+        )
+
     @testing.requires.fetch_null_from_numeric
     def test_numeric_null_as_decimal(self, do_numeric_test):
         do_numeric_test(Numeric(precision=8, scale=4), [None], [None])
diff --git a/test/requirements.py b/test/requirements.py
index 3b77bf6721..134ddbdfa4 100644
--- a/test/requirements.py
+++ b/test/requirements.py
@@ -1172,6 +1172,14 @@ class DefaultRequirements(SuiteRequirements):
             ]
         )
 
+    @property
+    def infinity_floats(self):
+        return fails_on_everything_except(
+            "sqlite", "postgresql+psycopg2", "postgresql+asyncpg"
+        ) + skip_if(
+            "postgresql+pg8000", "seems to work on pg14 only, not earlier?"
+        )
+
     @property
     def precision_generic_float_type(self):
         """target backend will return native floating point numbers with at
-- 
2.47.2