Implement variables of primitive types

Missing features:

- Input types
- Default values

Author: tomhoule

graphql_query_derive/src/lib.rs

@@ -29,6 +29,7 @@ mod schema;
 mod selection;
 mod shared;
 mod unions;
+mod variables;
 
 #[cfg(test)]
 mod tests;

graphql_query_derive/src/query.rs

@@ -1,18 +1,19 @@
 use failure;
-use field_type::FieldType;
 use fragments::GqlFragment;
-use proc_macro2::TokenStream;
+use graphql_parser;
+use proc_macro2::{Ident, Span, TokenStream};
 use schema::Schema;
 use selection::Selection;
 use std::collections::BTreeMap;
+use variables::Variable;
 
 pub struct QueryContext {
     pub _subscription_root: Option<Vec<TokenStream>>,
     pub fragments: BTreeMap<String, GqlFragment>,
     pub mutation_root: Option<Vec<TokenStream>>,
     pub query_root: Option<Vec<TokenStream>>,
     pub schema: Schema,
-    pub variables: BTreeMap<String, FieldType>,
+    pub variables: Vec<Variable>,
 }
 
 impl QueryContext {
@@ -23,7 +24,34 @@ impl QueryContext {
             mutation_root: None,
             query_root: None,
             schema,
-            variables: BTreeMap::new(),
+            variables: Vec::new(),
+        }
+    }
+
+    pub fn register_variables(&mut self, variables: &[graphql_parser::query::VariableDefinition]) {
+        variables.iter().for_each(|variable| {
+            self.variables.push(variable.clone().into());
+        });
+    }
+
+    pub fn expand_variables(&self) -> TokenStream {
+        if self.variables.is_empty() {
+            return quote!(#[derive(Serialize)]
+            pub struct Variables;);
+        }
+
+        let fields = self.variables.iter().map(|variable| {
+            let name = &variable.name;
+            let ty = variable.ty.to_rust(self, name);
+            let name = Ident::new(name, Span::call_site());
+            quote!(pub #name: #ty)
+        });
+
+        quote! {
+            #[derive(Serialize)]
+            pub struct Variables {
+                #(#fields,)*
+            }
         }
     }
 
@@ -36,7 +64,7 @@ impl QueryContext {
             mutation_root: None,
             query_root: None,
             schema: Schema::new(),
-            variables: BTreeMap::new(),
+            variables: Vec::new(),
         }
     }
 

graphql_query_derive/src/schema.rs

@@ -67,6 +67,8 @@ impl Schema {
                             definition.response_fields_for_selection(&context, &selection, &prefix),
                         )
                     };
+
+                    context.register_variables(&q.variable_definitions);
                 }
                 query::Definition::Operation(query::OperationDefinition::Mutation(q)) => {
                     context.mutation_root = {
@@ -87,6 +89,8 @@ impl Schema {
                             definition.response_fields_for_selection(&context, &selection, &prefix),
                         )
                     };
+
+                    context.register_variables(&q.variable_definitions);
                 }
                 query::Definition::Operation(query::OperationDefinition::Subscription(q)) => {
                     context._subscription_root = {
@@ -109,6 +113,8 @@ impl Schema {
                             definition.response_fields_for_selection(&context, &selection, &prefix),
                         )
                     };
+
+                    context.register_variables(&q.variable_definitions);
                 }
                 query::Definition::Operation(query::OperationDefinition::SelectionSet(_)) => {
                     unimplemented!()
@@ -132,8 +138,7 @@ impl Schema {
             .fragments
             .values()
             .map(|fragment| fragment.to_rust(&context));
-        let variables_struct = quote!(#[derive(Serialize)]
-        pub struct Variables;);
+        let variables_struct = context.expand_variables();
         let response_data_fields = context
             .query_root
             .as_ref()

graphql_query_derive/src/variables.rs

@@ -0,0 +1,19 @@
+use field_type::FieldType;
+use graphql_parser;
+
+#[derive(Debug)]
+pub struct Variable {
+    pub name: String,
+    pub ty: FieldType,
+    pub default: Option<graphql_parser::query::Value>,
+}
+
+impl ::std::convert::From<graphql_parser::query::VariableDefinition> for Variable {
+    fn from(def: graphql_parser::query::VariableDefinition) -> Variable {
+        Variable {
+            name: def.name,
+            ty: FieldType::from(def.var_type),
+            default: def.default_value,
+        }
+    }
+}

tests/introspection.rs

@@ -9,6 +9,7 @@ extern crate serde;
     query_path = "tests/introspection_query.graphql",
     schema_path = "tests/introspection_schema.graphql"
 )]
+#[allow(dead_code)]
 struct IntrospectionQuery;
 
 #[test]

tests/scalar_variables.rs

@@ -0,0 +1,21 @@
+#[macro_use]
+extern crate graphql_client;
+#[macro_use]
+extern crate serde_derive;
+extern crate serde;
+
+#[derive(GraphQLQuery)]
+#[GraphQLQuery(
+    query_path = "tests/scalar_variables_query.graphql",
+    schema_path = "tests/scalar_variables_schema.graphql"
+)]
+#[allow(dead_code)]
+struct ScalarVariablesQuery;
+
+#[test]
+fn scalar_variables_query_variables_struct() {
+    scalar_variables_query::Variables {
+        msg: "hello".to_string(),
+        reps: Some(32),
+    };
+}

tests/scalar_variables_query.graphql

@@ -0,0 +1,5 @@
+query VariablesQuery($msg: String!, $reps: Int) {
+    echo(message: $msg, repetitions: $reps) {
+        result
+    }
+}

tests/scalar_variables_schema.graphql

@@ -0,0 +1,12 @@
+
+schema {
+    query: ScalarVariablesQuery
+}
+
+type ScalarVariablesQuery {
+    echo(message: String!, repetitions: Int): EchoResult
+}
+
+type EchoResult {
+    result: String!
+}