Unify handling of calls (#614)

Instead of having `Expr::VarCall`, `Expr::PathCall` and
`Expr::MethodCall`, this PR unifies the handling of calls by removing
the former three variants, and introducing `Expr::Call`.

1 files changed, 82 insertions, 0 deletions

diff --git a/testing/tests/calls.rs b/testing/tests/calls.rs
new file mode 100644
index 0000000..052f34f
--- /dev/null
+++ b/testing/tests/calls.rs
@@ -0,0 +1,82 @@
+use askama::Template;
+
+#[derive(Template)]
+#[template(source = "{{ func(value) }}", ext = "txt")]
+struct OneFunction {
+    func: fn(&i32) -> i32,
+    value: i32,
+}
+
+#[test]
+fn test_one_func() {
+    let t = OneFunction {
+        func: |&i| 2 * i,
+        value: 123,
+    };
+    assert_eq!(t.render().unwrap(), "246");
+}
+
+#[derive(Template)]
+#[template(source = "{{ self.func(value) }}", ext = "txt")]
+struct OneFunctionSelf {
+    value: i32,
+}
+
+impl OneFunctionSelf {
+    fn func(&self, i: &i32) -> i32 {
+        2 * i
+    }
+}
+
+#[test]
+fn test_one_func_self() {
+    let t = OneFunctionSelf { value: 123 };
+    assert_eq!(t.render().unwrap(), "246");
+}
+
+#[derive(Template)]
+#[template(source = "{{ func[index](value) }}", ext = "txt")]
+struct OneFunctionIndex<'a> {
+    func: &'a [fn(&i32) -> i32],
+    value: i32,
+    index: usize,
+}
+
+#[test]
+fn test_one_func_index() {
+    let t = OneFunctionIndex {
+        func: &[|_| panic!(), |&i| 2 * i, |_| panic!(), |_| panic!()],
+        value: 123,
+        index: 1,
+    };
+    assert_eq!(t.render().unwrap(), "246");
+}
+
+struct AddToGetAFunction;
+
+impl std::ops::Add<usize> for &AddToGetAFunction {
+    type Output = fn(&i32) -> i32;
+
+    fn add(self, rhs: usize) -> Self::Output {
+        assert_eq!(rhs, 1);
+        |&i| 2 * i
+    }
+}
+
+#[derive(Template)]
+#[template(source = "{{ (func + index)(value) }}", ext = "txt")]
+struct OneFunctionBinop<'a> {
+    func: &'a AddToGetAFunction,
+    value: i32,
+    index: usize,
+}
+
+#[test]
+fn test_one_func_binop() {
+    let t = OneFunctionBinop {
+        func: &AddToGetAFunction,
+        value: 123,
+        index: 1,
+    };
+    assert_eq!(t.render().unwrap(), "246");
+}