From c33e89ba58c69096e041a54d210195d3520376b7 Mon Sep 17 00:00:00 2001
From: bogay <pojay11523@gmail.com>
Date: Wed, 11 Oct 2023 22:15:10 +0800
Subject: [PATCH] test(Export): add UI tests

---
 gdnative-derive/src/export.rs           | 27 ++++++++++++-------------
 gdnative/tests/ui.rs                    |  3 +++
 gdnative/tests/ui/export_fail_02.rs     |  8 ++++++++
 gdnative/tests/ui/export_fail_02.stderr |  5 +++++
 gdnative/tests/ui/export_fail_03.rs     |  8 ++++++++
 gdnative/tests/ui/export_fail_03.stderr | 11 ++++++++++
 gdnative/tests/ui/export_pass.rs        | 11 ++++++++++
 7 files changed, 59 insertions(+), 14 deletions(-)
 create mode 100644 gdnative/tests/ui/export_fail_02.rs
 create mode 100644 gdnative/tests/ui/export_fail_02.stderr
 create mode 100644 gdnative/tests/ui/export_fail_03.rs
 create mode 100644 gdnative/tests/ui/export_fail_03.stderr
 create mode 100644 gdnative/tests/ui/export_pass.rs

diff --git a/gdnative-derive/src/export.rs b/gdnative-derive/src/export.rs
index 8efa519f0..7e11b5b38 100644
--- a/gdnative-derive/src/export.rs
+++ b/gdnative-derive/src/export.rs
@@ -1,14 +1,19 @@
-use proc_macro2::TokenStream as TokenStream2;
+use proc_macro2::{Span, TokenStream as TokenStream2};
+use syn::spanned::Spanned;
 use syn::{DeriveInput, Fields};
 
+fn err_only_supports_fieldless_enums(span: Span) -> syn::Error {
+    syn::Error::new(span, "#[derive(Export)] only supports fieldless enums")
+}
+
 pub(crate) fn derive_export(input: &DeriveInput) -> syn::Result<TokenStream2> {
     let derived_enum = match &input.data {
         syn::Data::Enum(data) => data,
-        _ => {
-            return Err(syn::Error::new(
-                input.ident.span(),
-                "#[derive(Export)] only supports fieldless enums",
-            ))
+        syn::Data::Struct(data) => {
+            return Err(err_only_supports_fieldless_enums(data.struct_token.span()));
+        }
+        syn::Data::Union(data) => {
+            return Err(err_only_supports_fieldless_enums(data.union_token.span()));
         }
     };
 
@@ -20,14 +25,8 @@ fn impl_export(enum_ty: &syn::Ident, data: &syn::DataEnum) -> syn::Result<TokenS
     let err = data
         .variants
         .iter()
-        .filter_map(|variant| {
-            (!matches!(variant.fields, Fields::Unit)).then(|| {
-                syn::Error::new(
-                    variant.ident.span(),
-                    "#[derive(Export)] only supports fieldless enums",
-                )
-            })
-        })
+        .filter(|variant| !matches!(variant.fields, Fields::Unit))
+        .map(|variant| err_only_supports_fieldless_enums(variant.ident.span()))
         .reduce(|mut acc, err| {
             acc.combine(err);
             acc
diff --git a/gdnative/tests/ui.rs b/gdnative/tests/ui.rs
index 99a54ffdb..4a8684396 100644
--- a/gdnative/tests/ui.rs
+++ b/gdnative/tests/ui.rs
@@ -42,7 +42,10 @@ fn ui_tests() {
     t.compile_fail("tests/ui/from_variant_fail_09.rs");
 
     // Export
+    t.pass("tests/ui/export_pass.rs");
     t.compile_fail("tests/ui/export_fail_01.rs");
+    t.compile_fail("tests/ui/export_fail_02.rs");
+    t.compile_fail("tests/ui/export_fail_03.rs");
 }
 
 // FIXME(rust/issues/54725): Full path spans are only available on nightly as of now
diff --git a/gdnative/tests/ui/export_fail_02.rs b/gdnative/tests/ui/export_fail_02.rs
new file mode 100644
index 000000000..7ce4c080e
--- /dev/null
+++ b/gdnative/tests/ui/export_fail_02.rs
@@ -0,0 +1,8 @@
+use gdnative::prelude::*;
+
+#[derive(Export, ToVariant)]
+pub struct Foo {
+    bar: i32,
+}
+
+fn main() {}
diff --git a/gdnative/tests/ui/export_fail_02.stderr b/gdnative/tests/ui/export_fail_02.stderr
new file mode 100644
index 000000000..288715542
--- /dev/null
+++ b/gdnative/tests/ui/export_fail_02.stderr
@@ -0,0 +1,5 @@
+error: #[derive(Export)] only supports fieldless enums
+ --> tests/ui/export_fail_02.rs:4:5
+  |
+4 | pub struct Foo {
+  |     ^^^^^^
diff --git a/gdnative/tests/ui/export_fail_03.rs b/gdnative/tests/ui/export_fail_03.rs
new file mode 100644
index 000000000..d89f24118
--- /dev/null
+++ b/gdnative/tests/ui/export_fail_03.rs
@@ -0,0 +1,8 @@
+use gdnative::prelude::*;
+
+#[derive(Export, ToVariant)]
+pub union Foo {
+    bar: i32,
+}
+
+fn main() {}
diff --git a/gdnative/tests/ui/export_fail_03.stderr b/gdnative/tests/ui/export_fail_03.stderr
new file mode 100644
index 000000000..304eff3b3
--- /dev/null
+++ b/gdnative/tests/ui/export_fail_03.stderr
@@ -0,0 +1,11 @@
+error: #[derive(Export)] only supports fieldless enums
+ --> tests/ui/export_fail_03.rs:4:5
+  |
+4 | pub union Foo {
+  |     ^^^^^
+
+error: Variant conversion derive macro does not work on unions.
+ --> tests/ui/export_fail_03.rs:4:1
+  |
+4 | pub union Foo {
+  | ^^^
diff --git a/gdnative/tests/ui/export_pass.rs b/gdnative/tests/ui/export_pass.rs
new file mode 100644
index 000000000..a5b12b5de
--- /dev/null
+++ b/gdnative/tests/ui/export_pass.rs
@@ -0,0 +1,11 @@
+use gdnative::prelude::*;
+
+#[derive(Export, ToVariant, Clone, Copy)]
+#[variant(enum = "repr")]
+#[repr(i32)]
+pub enum Foo {
+    Bar,
+    Baz,
+}
+
+fn main() {}