draft @include for IsOneOf for introspection with cli option

Author: jimmystewpot

graphql_client_cli/src/graphql/introspection_query.graphql

@@ -1,4 +1,4 @@
-query IntrospectionQuery {
+query IntrospectionQuery($isOneOf: Boolean!) {
   __schema {
     queryType {
       name
@@ -27,7 +27,7 @@ fragment FullType on __Type {
   kind
   name
   description
-  isOneOf
+  isOneOf @include(if: $isOneOf)
   fields(includeDeprecated: true) {
     name
     description

graphql_client_cli/src/graphql/introspection_schema.graphql

@@ -104,4 +104,4 @@ enum __DirectiveLocation {
   ENUM_VALUE
   INPUT_OBJECT
   INPUT_FIELD_DEFINITION
-}
+}

graphql_client_cli/src/introspect_schema.rs

@@ -1,10 +1,15 @@
 use crate::error::Error;
 use crate::CliResult;
-use graphql_client::GraphQLQuery;
+use graphql_client::{GraphQLQuery, QueryBody};
 use reqwest::header::{HeaderMap, HeaderValue, ACCEPT, CONTENT_TYPE};
+use serde_json::json;
+use std::fmt;
 use std::path::PathBuf;
 use std::str::FromStr;
 
+use clap::ValueEnum;
+use introspection_query::Variables;
+
 #[derive(GraphQLQuery)]
 #[graphql(
     schema_path = "src/graphql/introspection_schema.graphql",
@@ -21,6 +26,7 @@ pub fn introspect_schema(
     authorization: Option<String>,
     headers: Vec<Header>,
     no_ssl: bool,
+    options: Option<Vec<IntrospectionOptions>>,
 ) -> CliResult<()> {
     use std::io::Write;
 
@@ -29,11 +35,8 @@ pub fn introspect_schema(
         None => Box::new(std::io::stdout()),
     };
 
-    let request_body: graphql_client::QueryBody<()> = graphql_client::QueryBody {
-        variables: (),
-        query: introspection_query::QUERY,
-        operation_name: introspection_query::OPERATION_NAME,
-    };
+    let request_body: QueryBody<introspection_query::Variables> =
+        IntrospectionQuery::build_query(construct_options(options));
 
     let client = reqwest::blocking::Client::builder()
         .danger_accept_invalid_certs(no_ssl)
@@ -126,6 +129,41 @@ impl FromStr for Header {
     }
 }
 
+#[derive(ValueEnum, Clone, Debug, PartialEq)]
+pub enum IntrospectionOptions {
+    /// Enable the @oneOf directive in the introspection query.
+    IsOneOf,
+    /// SpecifiedBy is is used within the type system definition language to
+    /// provide a scalar specification URL for specifying the behavior of custom scalar types.
+    SpecifiedBy,
+}
+
+fn construct_options(options: Option<Vec<IntrospectionOptions>>) -> introspection_query::Variables {
+    match options {
+        Some(opts) => introspection_query::Variables {
+            is_one_of: opts.contains(&IntrospectionOptions::IsOneOf),
+        },
+        None => introspection_query::Variables { is_one_of: false },
+    }
+}
+
+impl FromStr for IntrospectionOptions {
+    type Err = String;
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        match input.to_lowercase().as_str() {
+            "isoneof" => Ok(IntrospectionOptions::IsOneOf),
+            _ => Err(format!("unknown option {:?}", input)),
+        }
+    }
+}
+
+impl fmt::Debug for Variables {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", json!(self))
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

graphql_client_cli/src/main.rs

@@ -5,6 +5,7 @@ mod introspect_schema;
 use clap::Parser;
 use env_logger::fmt::{Color, Style, StyledValue};
 use error::Error;
+use introspect_schema::IntrospectionOptions;
 use log::Level;
 use std::path::PathBuf;
 use Cli::Generate;
@@ -34,6 +35,10 @@ enum Cli {
         /// Default value is false.
         #[clap(long = "no-ssl")]
         no_ssl: bool,
+        /// Introspection Options
+        /// is-one-of will include IsOneOf in the introspection query.
+        #[clap(long = "options", action(clap::ArgAction::Append))]
+        options: Option<Vec<IntrospectionOptions>>,
     },
     #[clap(name = "generate")]
     Generate {
@@ -93,12 +98,14 @@ fn main() -> CliResult<()> {
             authorization,
             headers,
             no_ssl,
+            options,
         } => introspect_schema::introspect_schema(
             &schema_location,
             output,
             authorization,
             headers,
             no_ssl,
+            options,
         ),
         Generate {
             variables_derives,