Add serde_with

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
           override: true          
       - if: matrix.rust == '1.45.0'
         # work-around https://github.com/serde-rs/serde/issues/2255 and similar crate/rustc compatibility issues
-        run: cargo update -p serde --precise 1.0.142 && cargo update -p once_cell --precise 1.10.0 && cargo update -p pretty_assertions --precise 1.2.1
+        run: sed -i '/serde_with =/d' schemars/Cargo.toml && cargo update -p serde --precise 1.0.142 && cargo update -p once_cell --precise 1.10.0 && cargo update -p pretty_assertions --precise 1.2.1
       - name: Check with no feature flags
         run: cargo check --verbose --no-default-features
         continue-on-error: ${{ matrix.allow_failure }}

schemars/Cargo.toml

@@ -31,6 +31,7 @@ bytes = { version = "1.0", optional = true }
 rust_decimal = { version = "1", default-features = false, optional = true }
 bigdecimal = { version = "0.3", default-features = false, optional = true }
 enumset = { version = "1.0", optional = true }
+serde_with = { version = "2.2", optional = true, default-features = false, features = ["alloc"] }
 
 [dev-dependencies]
 pretty_assertions = "1.2.1"

schemars/src/json_schema_impls/mod.rs

@@ -61,6 +61,8 @@ mod nonzero_signed;
 mod nonzero_unsigned;
 mod primitives;
 mod sequences;
+#[cfg(feature = "serde_with")]
+mod serde_with;
 mod serdejson;
 #[cfg(feature = "smallvec")]
 mod smallvec;

schemars/src/json_schema_impls/serde_with.rs

@@ -0,0 +1,139 @@
+use serde_with::formats::Format;
+use serde_with::*;
+
+use crate::gen::SchemaGenerator;
+use crate::schema::*;
+use crate::JsonSchema;
+
+macro_rules! schema_impl {
+    ($ident:ident$(<$($T:ident$(:$Bound:path)?),+>)?, $name:block, $schema:block, $gen:ident) => {
+        impl$(<$($T: JsonSchema $(+ $Bound)?),+>)? JsonSchema for $ident $(<$($T),+>)? {
+            fn schema_name() -> String $name
+
+            fn json_schema($gen: &mut SchemaGenerator) -> Schema $schema
+        }
+    };
+    ($ident:ident$(<$($T:ident$(:$Bound:path)?),+>)? = $alias:ty) => {
+        schema_impl!($ident$(<$($T$(:$Bound)?),+>)?, { <$alias>::schema_name() }, { <$alias>::json_schema(gen) }, gen);
+    };
+}
+
+schema_impl!(As<T> = T);
+schema_impl!(BoolFromInt = u8);
+schema_impl!(Bytes = Vec<u8>);
+schema_impl!(
+    BytesOrString,
+    { "BytesOrString".to_owned() },
+    {
+        let mut schema = SchemaObject::default();
+        schema.subschemas().any_of = Some(vec![
+            gen.subschema_for::<Vec<u8>>(),
+            gen.subschema_for::<String>(),
+        ]);
+        schema.into()
+    },
+    gen
+);
+schema_impl!(DefaultOnError<T> = T);
+schema_impl!(DefaultOnNull<T> = T);
+schema_impl!(DisplayFromStr = String);
+
+macro_rules! with_format {
+    ($($ident:ident),*) => {
+        $( schema_impl!($ident<FORMAT: Format> = FORMAT);)*
+    };
+}
+with_format!(
+    DurationMicroSeconds,
+    DurationMicroSecondsWithFrac,
+    DurationMilliSeconds,
+    DurationMilliSecondsWithFrac,
+    DurationNanoSeconds,
+    DurationNanoSecondsWithFrac,
+    DurationSeconds,
+    DurationSecondsWithFrac
+);
+
+schema_impl!(FromInto<T> = T);
+schema_impl!(Map<K, V>,
+    { format!("Map_of_{}_to_{}", K::schema_name(), V::schema_name()) },
+    {
+        let subschema = gen.subschema_for::<V>();
+        SchemaObject {
+            instance_type: Some(InstanceType::Object.into()),
+            object: Some(Box::new(ObjectValidation {
+                additional_properties: Some(Box::new(subschema)),
+                ..Default::default()
+            })),
+            ..Default::default()
+        }
+        .into()
+    },
+    gen
+);
+schema_impl!(NoneAsEmptyString = Option<String>);
+schema_impl!(
+    OneOrMany<T>,
+    { format!("OneOrMany_of_{}", T::schema_name()) },
+    {
+        let mut schema = SchemaObject::default();
+        schema.subschemas().any_of = Some(vec![
+            gen.subschema_for::<Vec<T>>(),
+            gen.subschema_for::<T>(),
+        ]);
+        schema.into()
+    },
+    gen
+);
+
+impl<T: JsonSchema> JsonSchema for PickFirst<(T,)> {
+    fn schema_name() -> String {
+        T::schema_name()
+    }
+    fn json_schema(gen: &mut crate::gen::SchemaGenerator) -> Schema {
+        T::json_schema(gen)
+    }
+}
+macro_rules! pick_first {
+    ($($Ts:ident),+, $fmt:literal) => {
+        impl<$($Ts: JsonSchema),+> JsonSchema for PickFirst<($($Ts),+)> {
+            fn schema_name() -> String {
+                format!($fmt, $($Ts::schema_name()),+)
+            }
+            fn json_schema(gen: &mut crate::gen::SchemaGenerator) -> Schema {
+                let mut schema = SchemaObject::default();
+                schema.subschemas().any_of =
+                    Some(vec![$(gen.subschema_for::<$Ts>()),+]);
+                schema.into()
+            }
+        }
+    };
+}
+// only implemented for 1-4
+pick_first!(A, B, "{}_or_{}");
+pick_first!(A, B, C, "{}_or_{}_or_{}");
+pick_first!(A, B, C, D, "{}_or_{}_or_{}_or_{}");
+
+schema_impl!(Seq<T> = Vec<T>);
+impl<Sep, T: JsonSchema> JsonSchema for StringWithSeparator<Sep, T> {
+    fn schema_name() -> String {
+        T::schema_name()
+    }
+    fn json_schema(gen: &mut crate::gen::SchemaGenerator) -> Schema {
+        T::json_schema(gen)
+    }
+}
+
+with_format!(
+    TimestampMicroSeconds,
+    TimestampMicroSecondsWithFrac,
+    TimestampMilliSeconds,
+    TimestampMilliSecondsWithFrac,
+    TimestampNanoSeconds,
+    TimestampNanoSecondsWithFrac,
+    TimestampSeconds,
+    TimestampSecondsWithFrac
+);
+
+schema_impl!(TryFromInto<T> = T);
+schema_impl!(VecSkipError<T> = Vec<T>);