Parse tuple expressions

Askama understands how to destructure tuples in let and match
statements, but it does not understand how to build a tuple.

This PR fixes this shortcoming.

1 files changed, 82 insertions, 0 deletions

diff --git a/testing/tests/tuple.rs b/testing/tests/tuple.rs
new file mode 100644
index 0000000..37d313c
--- /dev/null
+++ b/testing/tests/tuple.rs
@@ -0,0 +1,82 @@
+use askama::Template;
+
+struct Post {
+    id: u32,
+}
+
+struct Client<'a> {
+    can_post_ids: &'a [u32],
+    can_update_ids: &'a [u32],
+}
+
+impl Client<'_> {
+    fn can_post(&self, post: &Post) -> bool {
+        self.can_post_ids.contains(&post.id)
+    }
+
+    fn can_update(&self, post: &Post) -> bool {
+        self.can_update_ids.contains(&post.id)
+    }
+}
+
+#[derive(Template)]
+#[template(
+    source = r#"
+{%- match (client.can_post(post), client.can_update(post)) -%}
+    {%- when (false, false) -%}
+        No!
+    {%- when (can_post, can_update) -%}
+        <ul>
+        {%- if can_post -%}<li>post</li>{%- endif -%}
+        {%- if can_update -%}<li>update</li>{%- endif -%}
+        </ul>
+{%- endmatch -%}
+"#,
+    ext = "txt"
+)]
+struct TupleTemplate<'a> {
+    client: &'a Client<'a>,
+    post: &'a Post,
+}
+
+#[test]
+fn test_tuple() {
+    let template = TupleTemplate {
+        client: &Client {
+            can_post_ids: &[1, 2],
+            can_update_ids: &[2, 3],
+        },
+        post: &Post { id: 1 },
+    };
+    assert_eq!(template.render().unwrap(), "<ul><li>post</li></ul>");
+
+    let template = TupleTemplate {
+        client: &Client {
+            can_post_ids: &[1, 2],
+            can_update_ids: &[2, 3],
+        },
+        post: &Post { id: 2 },
+    };
+    assert_eq!(
+        template.render().unwrap(),
+        "<ul><li>post</li><li>update</li></ul>"
+    );
+
+    let template = TupleTemplate {
+        client: &Client {
+            can_post_ids: &[1, 2],
+            can_update_ids: &[2, 3],
+        },
+        post: &Post { id: 3 },
+    };
+    assert_eq!(template.render().unwrap(), "<ul><li>update</li></ul>");
+
+    let template = TupleTemplate {
+        client: &Client {
+            can_post_ids: &[1, 2],
+            can_update_ids: &[2, 3],
+        },
+        post: &Post { id: 4 },
+    };
+    assert_eq!(template.render().unwrap(), "No!");
+}