From c96de85dccb09cb6064bb1151845415058bb9cc9 Mon Sep 17 00:00:00 2001
From: Peter Maatman <blackwolf12333@gmail.com>
Date: Sat, 18 Apr 2020 13:58:23 +0200
Subject: [PATCH] json: Refactor Encode/Decode for serde values to be generic
 for DB

Since the implementation of Encode and Decode for both mysql and
postgres on serde's Value and RawValue were practically the same they
were moved to the generic json module.
---
 Cargo.lock                           |  5 ++--
 sqlx-core/src/mysql/types/json.rs    | 12 ---------
 sqlx-core/src/postgres/types/json.rs | 24 ------------------
 sqlx-core/src/types.rs               | 38 ++++++++++++++++++++++++++++
 4 files changed, 41 insertions(+), 38 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1508f4a88c..95eb948088 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -125,9 +125,9 @@ dependencies = [
 
 [[package]]
 name = "async-trait"
-version = "0.1.27"
+version = "0.1.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "991d0a1a3e790c835fd54ab41742a59251338d8c7577fe7d7f0170c7072be708"
+checksum = "da71fef07bc806586090247e971229289f64c210a278ee5ae419314eb386b31d"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -303,6 +303,7 @@ name = "cargo-sqlx"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "async-trait",
  "chrono",
  "dotenv",
  "futures 0.3.4",
diff --git a/sqlx-core/src/mysql/types/json.rs b/sqlx-core/src/mysql/types/json.rs
index d62c314834..5be6d68c85 100644
--- a/sqlx-core/src/mysql/types/json.rs
+++ b/sqlx-core/src/mysql/types/json.rs
@@ -14,18 +14,6 @@ impl Type<MySql> for JsonValue {
     }
 }
 
-impl Encode<MySql> for JsonValue {
-    fn encode(&self, buf: &mut Vec<u8>) {
-        (Box::new(Json(self)) as Box<dyn Encode<MySql>>).encode(buf)
-    }
-}
-
-impl<'de> Decode<'de, MySql> for JsonValue {
-    fn decode(value: MySqlValue<'de>) -> crate::Result<Self> {
-        <Json<Self> as Decode<MySql>>::decode(value).map(|item| item.0)
-    }
-}
-
 impl<T> Type<MySql> for Json<T> {
     fn type_info() -> MySqlTypeInfo {
         // MySql uses the CHAR type to pass JSON data from and to the client
diff --git a/sqlx-core/src/postgres/types/json.rs b/sqlx-core/src/postgres/types/json.rs
index ef2b82b05c..20aeedcda4 100644
--- a/sqlx-core/src/postgres/types/json.rs
+++ b/sqlx-core/src/postgres/types/json.rs
@@ -21,36 +21,12 @@ impl Type<Postgres> for JsonValue {
     }
 }
 
-impl Encode<Postgres> for JsonValue {
-    fn encode(&self, buf: &mut PgRawBuffer) {
-        (Box::new(Json(self)) as Box<dyn Encode<Postgres>>).encode(buf)
-    }
-}
-
-impl<'de> Decode<'de, Postgres> for JsonValue {
-    fn decode(value: PgValue<'de>) -> crate::Result<Self> {
-        <Json<Self> as Decode<Postgres>>::decode(value).map(|item| item.0)
-    }
-}
-
 impl Type<Postgres> for &'_ JsonRawValue {
     fn type_info() -> PgTypeInfo {
         <Json<Self> as Type<Postgres>>::type_info()
     }
 }
 
-impl Encode<Postgres> for &'_ JsonRawValue {
-    fn encode(&self, buf: &mut PgRawBuffer) {
-        (Box::new(Json(self)) as Box<dyn Encode<Postgres>>).encode(buf)
-    }
-}
-
-impl<'de> Decode<'de, Postgres> for &'de JsonRawValue {
-    fn decode(value: PgValue<'de>) -> crate::Result<Self> {
-        <Json<Self> as Decode<Postgres>>::decode(value).map(|item| item.0)
-    }
-}
-
 impl<T> Type<Postgres> for Json<T> {
     fn type_info() -> PgTypeInfo {
         PgTypeInfo::new(TypeId::JSONB, "JSONB")
diff --git a/sqlx-core/src/types.rs b/sqlx-core/src/types.rs
index 7bae04baa5..fa81786181 100644
--- a/sqlx-core/src/types.rs
+++ b/sqlx-core/src/types.rs
@@ -43,6 +43,12 @@ pub mod ipnetwork {
 
 #[cfg(feature = "json")]
 pub mod json {
+    use crate::database::Database;
+    use crate::decode::Decode;
+    use crate::encode::Encode;
+    use crate::value::HasRawValue;
+    use serde_json::value::RawValue as JsonRawValue;
+    use serde_json::Value as JsonValue;
     use std::ops::Deref;
 
     #[cfg_attr(docsrs, doc(cfg(feature = "json")))]
@@ -62,6 +68,38 @@ pub mod json {
             &self.0
         }
     }
+
+    impl<DB> Encode<DB> for JsonValue
+    where
+        Json<Self>: Encode<DB>,
+        DB: Database,
+    {
+        fn encode(&self, buf: &mut DB::RawBuffer) {
+            <Json<Self> as Encode<DB>>::encode(&Json(self.clone()), buf)
+        }
+    }
+
+    impl<'de, DB> Decode<'de, DB> for JsonValue
+    where
+        Json<Self>: Decode<'de, DB>,
+        DB: Database,
+    {
+        fn decode(value: <DB as HasRawValue<'de>>::RawValue) -> crate::Result<Self> {
+            <Json<Self> as Decode<DB>>::decode(value).map(|item| item.0)
+        }
+    }
+
+    // We don't have to implement Encode for JsonRawValue because that's covered by the default
+    // implementation for Encode
+    impl<'de, DB> Decode<'de, DB> for &'de JsonRawValue
+    where
+        Json<Self>: Decode<'de, DB>,
+        DB: Database,
+    {
+        fn decode(value: <DB as HasRawValue<'de>>::RawValue) -> crate::Result<Self> {
+            <Json<Self> as Decode<DB>>::decode(value).map(|item| item.0)
+        }
+    }
 }
 #[cfg(feature = "json")]
 pub use self::json::Json;