1 files changed, 103 insertions, 0 deletions
diff --git a/src/nfc.rs b/src/nfc.rs
new file mode 100644
index 0000000..70e936c
--- /dev/null
+++ b/src/nfc.rs
@@ -0,0 +1,103 @@
+use std::{fmt, string::String as StdString};
+
+use sqlx::{
+    encode::{Encode, IsNull},
+    Database, Decode, Type,
+};
+use unicode_normalization::UnicodeNormalization as _;
+
+#[derive(Clone, Debug, Default, Eq, PartialEq, serde::Deserialize, serde::Serialize)]
+#[serde(from = "StdString", into = "StdString")]
+pub struct String(StdString);
+
+impl fmt::Display for String {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self(value) = self;
+        value.fmt(f)
+    }
+}
+
+impl From<StdString> for String {
+    fn from(value: StdString) -> Self {
+        let value = value.nfc().collect();
+
+        Self(value)
+    }
+}
+
+impl From<String> for StdString {
+    fn from(value: String) -> Self {
+        let String(value) = value;
+        value
+    }
+}
+
+impl std::ops::Deref for String {
+    type Target = StdString;
+
+    fn deref(&self) -> &Self::Target {
+        let Self(value) = self;
+        value
+    }
+}
+
+// Type is manually implemented so that we can implement Decode to do
+// normalization on read. Implementation is otherwise based on
+// `#[derive(sqlx::Type)]` with the `#[sqlx(transparent)]` attribute.
+impl<DB> Type<DB> for String
+where
+    DB: Database,
+    StdString: Type<DB>,
+{
+    fn type_info() -> <DB as Database>::TypeInfo {
+        <StdString as Type<DB>>::type_info()
+    }
+
+    fn compatible(ty: &<DB as Database>::TypeInfo) -> bool {
+        <StdString as Type<DB>>::compatible(ty)
+    }
+}
+
+impl<'r, DB> Decode<'r, DB> for String
+where
+    DB: Database,
+    StdString: Decode<'r, DB>,
+{
+    fn decode(value: <DB as Database>::ValueRef<'r>) -> Result<Self, sqlx::error::BoxDynError> {
+        let value = StdString::decode(value)?;
+        let value = value.nfc().collect();
+        Ok(Self(value))
+    }
+}
+
+impl<'q, DB> Encode<'q, DB> for String
+where
+    DB: Database,
+    StdString: Encode<'q, DB>,
+{
+    fn encode_by_ref(
+        &self,
+        buf: &mut <DB as Database>::ArgumentBuffer<'q>,
+    ) -> Result<IsNull, sqlx::error::BoxDynError> {
+        let Self(value) = self;
+        value.encode_by_ref(buf)
+    }
+
+    fn encode(
+        self,
+        buf: &mut <DB as Database>::ArgumentBuffer<'q>,
+    ) -> Result<IsNull, sqlx::error::BoxDynError> {
+        let Self(value) = self;
+        value.encode(buf)
+    }
+
+    fn produces(&self) -> Option<<DB as Database>::TypeInfo> {
+        let Self(value) = self;
+        value.produces()
+    }
+
+    fn size_hint(&self) -> usize {
+        let Self(value) = self;
+        value.size_hint()
+    }
+}