feat: add __hash__ and __eq__ to Index (#1809)

pyproject.toml

@@ -192,6 +192,8 @@ source = ["tortoise"]
 [tool.coverage.report]
 show_missing = true
 
+[tool.ruff]
+line-length = 100
 [tool.ruff.lint]
 ignore = ["E501"]
 

tests/fields/test_db_index.py

@@ -3,6 +3,40 @@
 from tortoise import fields
 from tortoise.contrib import test
 from tortoise.exceptions import ConfigurationError
+from tortoise.indexes import Index
+
+
+class CustomIndex(Index):
+    def __init__(self, *args, **kw):
+        super().__init__(*args, **kw)
+        self._foo = ""
+
+
+class TestIndexHashEqual(test.TestCase):
+    def test_index_eq(self):
+        assert Index(fields=("id",)) == Index(fields=("id",))
+        assert CustomIndex(fields=("id",)) == CustomIndex(fields=("id",))
+        assert Index(fields=("id", "name")) == Index(fields=["id", "name"])
+
+        assert Index(fields=("id", "name")) != Index(fields=("name", "id"))
+        assert Index(fields=("id",)) != Index(fields=("name",))
+        assert CustomIndex(fields=("id",)) != Index(fields=("id",))
+
+    def test_index_hash(self):
+        assert hash(Index(fields=("id",))) == hash(Index(fields=("id",)))
+        assert hash(Index(fields=("id", "name"))) == hash(Index(fields=["id", "name"]))
+        assert hash(CustomIndex(fields=("id", "name"))) == hash(CustomIndex(fields=["id", "name"]))
+
+        assert hash(Index(fields=("id", "name"))) != hash(Index(fields=["name", "id"]))
+        assert hash(Index(fields=("id",))) != hash(Index(fields=("name",)))
+
+        indexes = {Index(fields=("id",))}
+        indexes.add(Index(fields=("id",)))
+        assert len(indexes) == 1
+        indexes.add(CustomIndex(fields=("id",)))
+        assert len(indexes) == 2
+        indexes.add(Index(fields=("name",)))
+        assert len(indexes) == 3
 
 
 class TestIndexAlias(test.TestCase):

tortoise/indexes.py

@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING, Optional, Tuple, Type
+from typing import TYPE_CHECKING, Any, Optional, Tuple, Type
 
 from pypika.terms import Term, ValueWrapper
 
@@ -59,6 +59,12 @@ def get_sql(
     def index_name(self, schema_generator: "BaseSchemaGenerator", model: "Type[Model]") -> str:
         return self.name or schema_generator._generate_index_name("idx", model, self.fields)
 
+    def __hash__(self) -> int:
+        return hash((tuple(self.fields), self.name, tuple(self.expressions)))
+
+    def __eq__(self, other: Any) -> bool:
+        return type(self) is type(other) and self.__dict__ == other.__dict__
+
 
 class PartialIndex(Index):
     def __init__(