Print fragment variables

Reviewed By: mjmahone

Differential Revision: D35746920

fbshipit-source-id: 2f4573c2afa1bfa3536572e7dd4ce6f47fae4664

compiler/crates/graphql-text-printer/src/print_to_text.rs

@@ -5,14 +5,14 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-use common::{Named, WithLocation};
+use common::{Named, NamedItem, WithLocation};
 use graphql_ir::{
     Argument, Condition, ConditionValue, ConstantValue, Directive, ExecutableDefinition,
     FragmentDefinition, FragmentSpread, InlineFragment, LinkedField, OperationDefinition,
     ScalarField, Selection, Value, VariableDefinition,
 };
 use graphql_syntax::OperationKind;
-use intern::string_key::StringKey;
+use intern::string_key::{Intern, StringKey};
 use schema::{SDLSchema, Schema};
 use std::fmt::{Result as FmtResult, Write};
 
@@ -187,12 +187,16 @@ impl<'schema, 'writer, W: Write> Printer<'schema, 'writer, W> {
     fn print_fragment(mut self, fragment: &FragmentDefinition) -> FmtResult {
         let fragment_name = fragment.name.item;
         let type_condition_name = self.schema.get_type_name(fragment.type_condition);
-        write!(
-            self.writer,
-            "fragment {} on {}",
-            fragment_name, type_condition_name
-        )
-        .unwrap();
+        write!(self.writer, "fragment {}", fragment_name)?;
+        if fragment
+            .directives
+            .named("argumentDefinitions".intern())
+            .is_none()
+        {
+            self.print_variable_definitions(&fragment.variable_definitions)?;
+        }
+        write!(self.writer, " on {}", type_condition_name)?;
+
         self.print_directives(
             &fragment.directives,
             None,

compiler/crates/graphql-text-printer/tests/print/fixtures/fragment_variables.expected

@@ -0,0 +1,27 @@
+==================================== INPUT ====================================
+fragment MyFragment($some_arg: String, $another_arg: [Int]!) on Query {
+  my_alias: node(id: $id) {
+    id
+    ... on User {
+      name
+      likers(first: $count) {
+        count
+      }
+    }
+  }
+}
+==================================== OUTPUT ===================================
+fragment MyFragment(
+  $some_arg: String
+  $another_arg: [Int]!
+) on Query {
+  my_alias: node(id: $id) {
+    id
+    ... on User {
+      name
+      likers(first: $count) {
+        count
+      }
+    }
+  }
+}

compiler/crates/graphql-text-printer/tests/print/fixtures/fragment_variables.graphql

@@ -0,0 +1,11 @@
+fragment MyFragment($some_arg: String, $another_arg: [Int]!) on Query {
+  my_alias: node(id: $id) {
+    id
+    ... on User {
+      name
+      likers(first: $count) {
+        count
+      }
+    }
+  }
+}

compiler/crates/graphql-text-printer/tests/print/mod.rs

@@ -8,13 +8,20 @@
 use common::SourceLocationKey;
 use fixture_tests::Fixture;
 use graphql_ir::build;
-use graphql_syntax::parse_executable;
+use graphql_syntax::{parse_executable_with_features, ParserFeatures};
 use graphql_text_printer::print_ir;
 use relay_test_schema::TEST_SCHEMA;
 
 pub fn transform_fixture(fixture: &Fixture<'_>) -> Result<String, String> {
     let source_location = SourceLocationKey::standalone(fixture.file_name);
-    let ast = parse_executable(fixture.content, source_location).unwrap();
+    let ast = parse_executable_with_features(
+        fixture.content,
+        source_location,
+        ParserFeatures {
+            enable_variable_definitions: true,
+        },
+    )
+    .unwrap();
     build(&TEST_SCHEMA, &ast.definitions)
         .map(|definitions| print_ir(&TEST_SCHEMA, &definitions).join("\n\n"))
         .map_err(|errors| {

compiler/crates/graphql-text-printer/tests/print_test.rs

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<ed4f0587f716a12c400a0159b1a5b99c>>
+ * @generated SignedSource<<d33bba31770d0dda6327e188acc496a6>>
  */
 
 mod print;
@@ -75,6 +75,13 @@ fn empty_args() {
     test_fixture(transform_fixture, "empty_args.graphql", "print/fixtures/empty_args.expected", input, expected);
 }
 
+#[test]
+fn fragment_variables() {
+    let input = include_str!("print/fixtures/fragment_variables.graphql");
+    let expected = include_str!("print/fixtures/fragment_variables.expected");
+    test_fixture(transform_fixture, "fragment_variables.graphql", "print/fixtures/fragment_variables.expected", input, expected);
+}
+
 #[test]
 fn kitchen_sink() {
     let input = include_str!("print/fixtures/kitchen-sink.graphql");