Add tests for named arguments in macro calls

testing/tests/macro.rs

@@ -95,3 +95,33 @@ fn test_macro_self_arg() {
     let t = MacroSelfArgTemplate { s: "foo" };
     assert_eq!(t.render().unwrap(), "foo");
 }
+
+#[derive(Template)]
+#[template(
+    source = "{%- macro thrice(param1, param2) -%}
+{{ param1 }} {{ param2 }}
+{% endmacro -%}
+
+{%- call thrice(param1=2, param2=3) -%}
+{%- call thrice(param2=3, param1=2) -%}
+{%- call thrice(param2=3, 2) -%}
+{%- call thrice(3, param1=2) -%}
+",
+    ext = "html"
+)]
+struct MacroNamedArg;
+
+#[test]
+// We check that it's always the correct values passed to the
+// expected argument.
+fn test_named_argument() {
+    assert_eq!(
+        MacroNamedArg.render().unwrap(),
+        "\
+2 3
+2 3
+2 3
+2 3
+"
+    );
+}

testing/tests/ui/macro_named_argument.rs

@@ -0,0 +1,20 @@
+use askama::Template;
+
+#[derive(Template)]
+#[template(source = "{%- macro thrice(param1, param2) -%}
+{{ param1 }} {{ param2 }}
+{%- endmacro -%}
+
+{%- call thrice(param1=2, param3=3) -%}", ext = "html")]
+struct InvalidNamedArg;
+
+#[derive(Template)]
+#[template(source = "{%- macro thrice(param1, param2) -%}
+{{ param1 }} {{ param2 }}
+{%- endmacro -%}
+
+{%- call thrice(param1=2, param1=3) -%}", ext = "html")]
+struct InvalidNamedArg2;
+
+fn main() {
+}

testing/tests/ui/macro_named_argument.stderr

@@ -0,0 +1,17 @@
+error: no argument named `param3` in macro "thrice"
+ --> tests/ui/macro_named_argument.rs:3:10
+  |
+3 | #[derive(Template)]
+  |          ^^^^^^^^
+  |
+  = note: this error originates in the derive macro `Template` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: named argument `param1` was passed more than once
+       problems parsing template source at row 5, column 15 near:
+       "(param1=2, param1=3) -%}"
+  --> tests/ui/macro_named_argument.rs:11:10
+   |
+11 | #[derive(Template)]
+   |          ^^^^^^^^
+   |
+   = note: this error originates in the derive macro `Template` (in Nightly builds, run with -Z macro-backtrace for more info)