From 9e507272dab27a65717e7a6f70ceb5e0ff9f2480 Mon Sep 17 00:00:00 2001
From: Graham Esau <gesau@hotmail.co.uk>
Date: Fri, 16 Apr 2021 13:56:26 +0100
Subject: [PATCH] Process validation attributes in tuple structs

---
 schemars/tests/expected/validate_tuple.json | 18 +++++++++++
 schemars/tests/validate.rs                  | 11 +++++++
 schemars_derive/src/schema_exprs.rs         | 36 +++++++++++++++------
 3 files changed, 55 insertions(+), 10 deletions(-)
 create mode 100644 schemars/tests/expected/validate_tuple.json

diff --git a/schemars/tests/expected/validate_tuple.json b/schemars/tests/expected/validate_tuple.json
new file mode 100644
index 0000000..8ab6eaa
--- /dev/null
+++ b/schemars/tests/expected/validate_tuple.json
@@ -0,0 +1,18 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "Tuple",
+  "type": "array",
+  "items": [
+    {
+      "type": "integer",
+      "format": "uint8",
+      "maximum": 10.0,
+      "minimum": 0.0
+    },
+    {
+      "type": "boolean"
+    }
+  ],
+  "maxItems": 2,
+  "minItems": 2
+}
\ No newline at end of file
diff --git a/schemars/tests/validate.rs b/schemars/tests/validate.rs
index 8992df2..00d1b57 100644
--- a/schemars/tests/validate.rs
+++ b/schemars/tests/validate.rs
@@ -47,6 +47,17 @@ fn validate() -> TestResult {
     test_default_generated_schema::<Struct>("validate")
 }
 
+#[derive(Debug, JsonSchema)]
+pub struct Tuple(
+    #[validate(range(max = 10))] u8,
+    #[validate(required)] Option<bool>,
+);
+
+#[test]
+fn validate_tuple() -> TestResult {
+    test_default_generated_schema::<Tuple>("validate_tuple")
+}
+
 #[derive(Debug, JsonSchema)]
 pub struct NewType(#[validate(range(max = 10))] u8);
 
diff --git a/schemars_derive/src/schema_exprs.rs b/schemars_derive/src/schema_exprs.rs
index 261d6bc..739641c 100644
--- a/schemars_derive/src/schema_exprs.rs
+++ b/schemars_derive/src/schema_exprs.rs
@@ -61,7 +61,14 @@ fn expr_for_field(field: &Field, allow_ref: bool) -> TokenStream {
     let span = field.original.span();
     let gen = quote!(gen);
 
-    field.validation_attrs.apply_to_schema(if allow_ref {
+    let schema_expr = if field.validation_attrs.required {
+        quote_spanned! {span=>
+            {
+                #type_def
+                <#ty as schemars::JsonSchema>::_schemars_private_non_optional_json_schema(#gen)
+            }
+        }
+    } else if allow_ref {
         quote_spanned! {span=>
             {
                 #type_def
@@ -75,7 +82,8 @@ fn expr_for_field(field: &Field, allow_ref: bool) -> TokenStream {
                 <#ty as schemars::JsonSchema>::json_schema(#gen)
             }
         }
-    })
+    };
+    field.validation_attrs.apply_to_schema(schema_expr)
 }
 
 pub fn type_for_field_schema(field: &Field, local_id: usize) -> (syn::Type, Option<TokenStream>) {
@@ -375,17 +383,25 @@ fn expr_for_newtype_struct(field: &Field) -> TokenStream {
 }
 
 fn expr_for_tuple_struct(fields: &[Field]) -> TokenStream {
-    let (types, type_defs): (Vec<_>, Vec<_>) = fields
+    let fields: Vec<_> = fields
         .iter()
         .filter(|f| !f.serde_attrs.skip_deserializing())
-        .enumerate()
-        .map(|(i, f)| type_for_field_schema(f, i))
-        .unzip();
+        .map(|f| expr_for_field(f, true))
+        .collect();
+    let len = fields.len() as u32;
+
     quote! {
-        {
-            #(#type_defs)*
-            gen.subschema_for::<(#(#types),*)>()
-        }
+        schemars::schema::Schema::Object(
+            schemars::schema::SchemaObject {
+            instance_type: Some(schemars::schema::InstanceType::Array.into()),
+            array: Some(Box::new(schemars::schema::ArrayValidation {
+                items: Some(vec![#(#fields),*].into()),
+                max_items: Some(#len),
+                min_items: Some(#len),
+                ..Default::default()
+            })),
+            ..Default::default()
+        })
     }
 }