Cover arguments in Book

Author: tyranron

book/src/types/enums.md

@@ -75,7 +75,7 @@ enum Episode {
 
 ### Documentation and deprecation
 
-Just like when [defining GraphQL objects](objects/index.md#documentation), the [GraphQL enum][0] type and its values could be [documented][4] and [deprecated][5] via `#[graphql(description = "...")]` and `#[graphql(deprecated = "...")]`/[`#[deprecated]`][13] attributes:
+Just like when [defining GraphQL objects](objects/index.md#documentation), the [GraphQL enum][0] type and its values could be [documented][4] and [deprecated][9] via `#[graphql(description = "...")]` and `#[graphql(deprecated = "...")]`/[`#[deprecated]`][13] attributes:
 ```rust
 # extern crate juniper;
 # use juniper::GraphQLEnum;
@@ -105,7 +105,7 @@ enum StarWarsEpisode {
 #
 # fn main() {}
 ```
-> **NOTE**: Only [GraphQL object][6]/[interface][7] fields and [GraphQL enum][0] values can be [deprecated][5].
+> **NOTE**: Only [GraphQL object][6]/[interface][7]/[input object][8] fields, [arguments][5] and [GraphQL enum][0] values can be [deprecated][9].
 
 
 ### Ignoring
@@ -145,7 +145,9 @@ enum Episode<T> {
 [2]: https://docs.rs/juniper/0.17.0/juniper/derive.GraphQLEnum.html
 [3]: https://doc.rust-lang.org/reference/items/enumerations.html
 [4]: https://spec.graphql.org/October2021#sec-Descriptions
-[5]: https://spec.graphql.org/October2021#sec--deprecated
+[5]: https://spec.graphql.org/October2021#sec-Language.Arguments
 [6]: https://spec.graphql.org/October2021#sec-Objects
 [7]: https://spec.graphql.org/October2021#sec-Interfaces
-[13]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-deprecated-attribute
+[8]: https://spec.graphql.org/October2021#sec-Input-Objects
+[9]: https://spec.graphql.org/October2021#sec--deprecated
+[13]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-deprecated-attribute

book/src/types/interfaces.md

@@ -317,7 +317,7 @@ trait Person {
 
 ### Documentation and deprecation
 
-Similarly, [GraphQL fields][4] of [interfaces][0] may also be [documented][7] and [deprecated][9] via `#[graphql(description = "...")]` and `#[graphql(deprecated = "...")]`/[`#[deprecated]`][13] attributes:
+Similarly, [GraphQL fields][4] (and their [arguments][5]) of [interfaces][0] may also be [documented][7] and [deprecated][9] via `#[graphql(description = "...")]` and `#[graphql(deprecated = "...")]`/[`#[deprecated]`][13] attributes:
 ```rust
 # extern crate juniper;
 # use juniper::graphql_interface;
@@ -340,16 +340,24 @@ trait Person {
     /// This doc comment is visible in both Rust API docs and GraphQL schema 
     /// descriptions.
     #[graphql(deprecated = "Just because.")]
-    fn deprecated_graphql() -> bool;
+    fn deprecated_graphql(
+        // Only `Null`able arguments or non-`Null` arguments with default values
+        // can be deprecated.
+        #[graphql(default, deprecated = "No need.")] arg: bool,
+    ) -> bool;
 
     // Standard Rust's `#[deprecated]` attribute works too!
     #[deprecated(note = "Reason is optional, btw!")]
-    fn deprecated_standard() -> bool; // has no description in GraphQL schema
+    fn deprecated_standard( // has no description in GraphQL schema
+        // If no explicit deprecation reason is provided,
+        // then the default "No longer supported" one is used.
+        #[graphql(deprecated)] arg: Option<bool>,
+    ) -> bool;
 }
 #
 # fn main() {}
 ```
-> **NOTE**: Only [GraphQL interface][0]/[object][10] fields and [GraphQL enum][11] values can be [deprecated][9].
+> **NOTE**: Only [GraphQL interface][0]/[object][10]/[input object][8] fields, [arguments][5] and [GraphQL enum][11] values can be [deprecated][9].
 
 
 ### Ignoring
@@ -403,6 +411,7 @@ trait Person {
 [5]: https://spec.graphql.org/October2021#sec-Language.Arguments
 [6]: https://spec.graphql.org/October2021#sec-Non-Null
 [7]: https://spec.graphql.org/October2021#sec-Descriptions
+[8]: https://spec.graphql.org/October2021#sec-Input-Objects
 [9]: https://spec.graphql.org/October2021#sec--deprecated
 [10]: https://spec.graphql.org/October2021#sec-Objects
 [11]: https://spec.graphql.org/October2021#sec-Enums

book/src/types/objects/complex_fields.md

@@ -116,7 +116,7 @@ impl Person {
 
 ### Documentation and deprecation
 
-Similarly, [GraphQL fields][4] may also be [documented][7] and [deprecated][9] via `#[graphql(description = "...")]` and `#[graphql(deprecated = "...")]`/[`#[deprecated]`][13] attributes:
+Similarly, [GraphQL fields][4] (and their [arguments][5]) may also be [documented][7] and [deprecated][9] via `#[graphql(description = "...")]` and `#[graphql(deprecated = "...")]`/[`#[deprecated]`][13] attributes:
 ```rust
 # extern crate juniper;
 # use juniper::graphql_object;
@@ -145,20 +145,28 @@ impl Person {
     /// This doc comment is visible in both Rust API docs and GraphQL schema 
     /// descriptions.
     #[graphql(deprecated = "Just because.")]
-    fn deprecated_graphql() -> bool {
+    fn deprecated_graphql(
+        // Only `Null`able arguments or non-`Null` arguments with default values
+        // can be deprecated.
+        #[graphql(default, deprecated = "No need.")] arg: bool,
+    ) -> bool {
         true
     }
 
     // Standard Rust's `#[deprecated]` attribute works too!
     #[deprecated(note = "Reason is optional, btw!")]
-    fn deprecated_standard() -> bool { // has no description in GraphQL schema
+    fn deprecated_standard( // has no description in GraphQL schema
+        // If no explicit deprecation reason is provided,
+        // then the default "No longer supported" one is used.
+        #[graphql(deprecated)] arg: Option<bool>,
+    ) -> bool {
         false
     }
 }
 #
 # fn main() {}
 ```
-> **NOTE**: Only [GraphQL object][0]/[interface][11] fields and [GraphQL enum][10] values can be [deprecated][9].
+> **NOTE**: Only [GraphQL object][0]/[interface][11]/[input object][8] fields, [arguments][5] and [GraphQL enum][10] values can be [deprecated][9].
 
 
 ### Ignoring
@@ -223,6 +231,7 @@ impl Person {
 [5]: https://spec.graphql.org/October2021#sec-Language.Arguments
 [6]: https://doc.rust-lang.org/reference/items/implementations.html#inherent-implementations
 [7]: https://spec.graphql.org/October2021#sec-Descriptions
+[8]: https://spec.graphql.org/October2021#sec-Input-Objects
 [9]: https://spec.graphql.org/October2021#sec--deprecated
 [10]: https://spec.graphql.org/October2021#sec-Enums
 [11]: https://spec.graphql.org/October2021#sec-Interfaces

book/src/types/objects/error/field.md

@@ -37,11 +37,11 @@ impl Example {
 # fn main() {}
 ```
 
-[`FieldResult<T>`][21] is an alias for [`Result<T, FieldError>`][22], which is the [error type][1] all fallible [fields][6] must return. By using the [`?` operator][14], any type that implements the [`Display` trait][15] (which most of the error types out there do) can be automatically converted into a [`FieldError`][22].
+[`FieldResult<T>`][21] is an alias for [`Result<T, FieldError>`][22], which is the [error type][1] all fallible [fields][6] must return. By using the [`?` operator][14], any type that implements the [`Display` trait][19] (which most of the error types out there do) can be automatically converted into a [`FieldError`][22].
 
 > **TIP**: If a custom conversion into a [`FieldError`][22] is needed (to [fill up `extensions`][2], for example), the [`IntoFieldError` trait][23] should be implemented.
 
-> **NOTE**: [`FieldError`][22]s are [GraphQL field errors][1] and are [not visible][9] in a [GraphQL schema][8] in any way.
+> **NOTE**: [`FieldError`][22]s are [GraphQL field errors][1] and are [not visible][15] in a [GraphQL schema][8] in any way.
 
 
 
@@ -172,12 +172,12 @@ And the specified structured error information will be included into the [error'
 [6]: https://spec.graphql.org/October2021#sec-Language.Fields
 [7]: https://spec.graphql.org/October2021#sec-Response
 [8]: https://graphql.org/learn/schema
-[9]: https://spec.graphql.org/October2021#sec-Introspection
 [11]: https://doc.rust-lang.org/book/ch09-00-error-handling.html
 [12]: https://doc.rust-lang.org/stable/std/result/enum.Result.html
 [13]: https://doc.rust-lang.org/stable/std/macro.panic.html
 [14]: https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html#a-shortcut-for-propagating-errors-the--operator
-[15]: https://doc.rust-lang.org/stable/std/fmt/trait.Display.html
+[15]: https://spec.graphql.org/October2021#sec-Introspection
+[19]: https://doc.rust-lang.org/stable/std/fmt/trait.Display.html
 [21]: https://docs.rs/juniper/0.17.0/juniper/executor/type.FieldResult.html
 [22]: https://docs.rs/juniper/0.17.0/juniper/executor/struct.FieldError.html
 [23]: https://docs.rs/juniper/0.17.0/juniper/executor/trait.IntoFieldError.html

book/src/types/objects/index.md

@@ -34,7 +34,7 @@ This creates a [GraphQL object][0] type called `Person`, with two fields: `name`
 
 ### Documentation
 
-We should take advantage of the fact that [GraphQL] is [self-documenting][5] and add descriptions to the defined [GraphQL object][0] type and its fields. [Juniper] will automatically use associated [Rust doc comments][6] as [GraphQL descriptions][7]:
+We should take advantage of the fact that [GraphQL] is [self-documenting][15] and add descriptions to the defined [GraphQL object][0] type and its fields. [Juniper] will automatically use associated [Rust doc comments][6] as [GraphQL descriptions][7]:
 ```rust
 # extern crate juniper;
 # use juniper::GraphQLObject;
@@ -145,7 +145,7 @@ struct Person {
 #
 # fn main() {}
 ```
-> **NOTE**: Only [GraphQL object][0]/[interface][11] fields and [GraphQL enum][10] values can be [deprecated][9].
+> **NOTE**: Only [GraphQL object][0]/[interface][11]/[input object][8] fields, [arguments][5] and [GraphQL enum][10] values can be [deprecated][9].
 
 
 ### Ignoring
@@ -216,7 +216,7 @@ Because `Person` is a valid [GraphQL] type, we can have a `Vec<Person>` in a [st
 [2]: https://docs.rs/juniper/0.17.0/juniper/derive.GraphQLObject.html
 [3]: https://docs.rs/juniper/0.17.0/juniper/attr.graphql_object.html
 [4]: https://spec.graphql.org/October2021#sec-Non-Null
-[5]: https://spec.graphql.org/October2021#sec-Introspection
+[5]: https://spec.graphql.org/October2021#sec-Language.Arguments
 [6]: https://doc.rust-lang.org/reference/comments.html#doc-comments
 [7]: https://spec.graphql.org/October2021#sec-Descriptions
 [8]: https://spec.graphql.org/October2021#sec-Input-Objects
@@ -226,3 +226,4 @@ Because `Person` is a valid [GraphQL] type, we can have a `Vec<Person>` in a [st
 [12]: https://spec.graphql.org/October2021#sec-List
 [13]: https://doc.rust-lang.org/reference/attributes/diagnostics.html#the-deprecated-attribute
 [14]: https://spec.graphql.org/October2021#sel-EAFdRDHAAEJDAoBxzT
+[15]: https://spec.graphql.org/October2021#sec-Introspection