Function expression parsing into own folder

boa/src/syntax/parser/expression/primary/function_expression/mod.rs

@@ -7,6 +7,9 @@
 //! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/function
 //! [spec]: https://tc39.es/ecma262/#prod-FunctionExpression
 
+#[cfg(test)]
+mod tests;
+
 use crate::{
     syntax::{
         ast::{node::FunctionExpr, Keyword, Punctuator},

boa/src/syntax/parser/expression/primary/function_expression/tests.rs

@@ -0,0 +1,29 @@
+use crate::syntax::{
+    ast::{
+        node::{FunctionExpr, ConstDecl, ConstDeclList, Return, StatementList},
+        Const,
+    },
+    parser::tests::check_parser,
+};
+
+/// Checks async expression parsing.
+#[test]
+fn check_function_expression() {
+    check_parser(
+        "const add = function() {
+            return 1;
+        };
+        ",
+        vec![ConstDeclList::from(vec![ConstDecl::new(
+            "add",
+            Some(
+                FunctionExpr::new::<Option<Box<str>>, _, StatementList>(
+                    None,
+                    [],
+                    vec![Return::new::<_, _, Option<Box<str>>>(Const::from(1), None).into()].into(),
+                ),
+            ),
+        )])
+        .into()],
+    );
+}