Flag the whole json module behind the json feature

core/interop/src/modules/json.rs

@@ -1,3 +1,4 @@
+#![cfg(feature = "json")]
 //! Functions to create [`Module`]s that expose JSON data directly
 //! as the default export.
 #![allow(clippy::module_name_repetitions)]
@@ -9,7 +10,6 @@ use boa_engine::{js_string, Context, JsValue, Module};
 ///
 /// # Errors
 /// This will return an error if the JSON string is invalid or cannot be converted.
-#[cfg(feature = "json")]
 pub fn json_string_module(json: &str, context: &mut Context) -> boa_engine::JsResult<Module> {
     let json_value = serde_json::from_str::<serde_json::Value>(json).map_err(|e| {
         boa_engine::JsError::from_opaque(js_string!(format!("Failed to parse JSON: {}", e)).into())
@@ -18,7 +18,6 @@ pub fn json_string_module(json: &str, context: &mut Context) -> boa_engine::JsRe
     Ok(Module::from_value_as_default(value, context))
 }
 
-#[cfg(feature = "json")]
 #[test]
 fn test_json_module_from_str() {
     use crate::loaders::HashMapModuleLoader;