Add support for the `list` operator to the input value validator. #579

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Implement `TryFrom<&[SelectionField<'a>]>` for `Lookahead<'a>`. [#575](https://github.com/async-graphql/async-graphql/issues/575)
 - Attach custom HTTP headers to the response when an error occurs. [#572](https://github.com/async-graphql/async-graphql/issues/572)
 - Allow field visible to support paths. [#578](https://github.com/async-graphql/async-graphql/pull/578)
+- Add support for the `list` operator to the input value validator. [#579](https://github.com/async-graphql/async-graphql/issues/579)
 
 ## [2.9.8] 2021-07-12
 

derive/src/utils.rs

@@ -77,6 +77,23 @@ fn generate_nested_validator(
                         None => Some(item),
                     })
                     .unwrap())
+            } else if ls.path.is_ident("list") {
+                if ls.nested.len() > 1 {
+                    return Err(Error::new_spanned(
+                        ls,
+                        "Only one validator can be wrapped with list.",
+                    )
+                    .into());
+                }
+                if ls.nested.is_empty() {
+                    return Err(
+                        Error::new_spanned(ls, "At least one validator must be defined").into(),
+                    );
+                }
+                let validator = generate_nested_validator(crate_name, &ls.nested[0])?;
+                Ok(quote! {
+                    #crate_name::validators::List(#validator)
+                })
             } else {
                 let ty = &ls.path;
                 for item in &ls.nested {

docs/en/src/input_value_validators.md

@@ -24,7 +24,7 @@ impl Query {
 The following example verifies that the `i32` parameter `a` is greater than 10 and less than 100, or else equal to 0:
 
 ```rust
-use async_graphql:*;
+use async_graphql::*;
 use async_graphql::validators::{IntGreaterThan, IntLessThan, IntEqual};
 
 struct Query;
@@ -36,7 +36,23 @@ impl Query {
             and(IntGreaterThan(value = "10"), IntLessThan(value = "100")),
             IntEqual(value = "0")
         )))] a: String) {
-    } {
+    }
+}
+```
+
+## Validate the elements of the list.
+
+You can use the `list` operator to indicate that the internal validator is used for all elements in a list:
+
+```rust
+use async_graphql::*;
+use async_graphql::validators::Email;
+
+struct Query;
+
+#[Object]
+impl Query {
+    async fn input(#[graphql(validator(list(Email)))] emails: Vec<String>) {
     }
 }
 ```

docs/zh-CN/src/input_value_validators.md

@@ -22,7 +22,7 @@ impl Query {
 下面的例子校验`i32`类型的参数`a`必须大于10，并且小于100，或者等于0：
 
 ```rust
-use async_graphql:*;
+use async_graphql::*;
 use async_graphql::validators::{IntGreaterThan, IntLessThan, IntEqual};
 
 struct Query;
@@ -34,7 +34,23 @@ impl Query {
             and(IntGreaterThan(value = "10"), IntLessThan(value = "100")),
             IntEqual(value = "0")
         )))] a: String) {
-    } {
+    }
+}
+```
+
+## 校验列表成员
+
+你可以用`list`操作符表示内部的校验器作用于一个列表内的所有成员:
+
+```rust
+use async_graphql::*;
+use async_graphql::validators::{Email};
+
+struct Query;
+
+#[Object]
+impl Query {
+    async fn input(#[graphql(validator(list(Email)))] emails: Vec<String>) {
     }
 }
 ```

src/validators/list_validators.rs

@@ -48,3 +48,17 @@ impl InputValueValidator for ListMaxLength {
         }
     }
 }
+
+#[doc(hidden)]
+pub struct List<T>(pub T);
+
+impl<T: InputValueValidator> InputValueValidator for List<T> {
+    fn is_valid(&self, value: &Value) -> Result<(), String> {
+        if let Value::List(elems) = value {
+            for elem in elems {
+                self.0.is_valid(elem)?;
+            }
+        }
+        Ok(())
+    }
+}

src/validators/mod.rs

@@ -7,7 +7,7 @@ mod string_validators;
 use crate::{Error, Value};
 
 pub use int_validators::{IntEqual, IntGreaterThan, IntLessThan, IntNonZero, IntRange};
-pub use list_validators::{ListMaxLength, ListMinLength};
+pub use list_validators::{List, ListMaxLength, ListMinLength};
 pub use string_validators::{Email, StringMaxLength, StringMinLength, MAC};
 
 /// Input value validator

tests/input_validators.rs

@@ -1829,3 +1829,62 @@ pub async fn test_custom_input_validator_with_extensions() {
         }]
     );
 }
+
+#[tokio::test]
+pub async fn test_input_validator_list() {
+    struct QueryRoot;
+
+    #[derive(InputObject)]
+    struct InputEmail {
+        #[graphql(validator(list(Email)))]
+        pub emails: Vec<String>,
+    }
+
+    #[Object]
+    impl QueryRoot {
+        async fn value(&self, #[graphql(validator(list(Email)))] _emails: Vec<String>) -> bool {
+            true
+        }
+    }
+
+    let schema = Schema::new(QueryRoot, EmptyMutation, EmptySubscription);
+
+    assert_eq!(
+        schema
+            .execute(
+                r#"
+                {
+                    value(
+                        emails: [
+                            "a@a.com",
+                            "b@abc.com",
+                        ]
+                    )
+                }"#
+            )
+            .await
+            .into_result()
+            .unwrap()
+            .data,
+        value!({"value": true})
+    );
+
+    assert_eq!(
+        schema
+            .execute(
+                r#"
+                {
+                    value(
+                        emails: [
+                            "123456",
+                        ]
+                    )
+                }"#
+            )
+            .await
+            .into_result()
+            .unwrap_err()[0]
+            .message,
+        "Invalid value for argument \"emails\", invalid email format"
+    );
+}