Merge pull request #680 from GuillaumeGomez/fix-invalid-variable-parsing

Fix invalid variable parsing

Author: GuillaumeGomez

askama_derive/src/generator/expr.rs

@@ -1146,10 +1146,19 @@ fn starts_with_self_dot(expr_code: &TokenStream) -> bool {
 }
 
 fn write_resolved(buf: &mut Buffer, resolved: &str, span: proc_macro2::Span) {
-    for (idx, name) in resolved.split('.').enumerate() {
-        if idx > 0 {
-            buf.write_token(Token![.], span);
+    if resolved.contains('(') {
+        // FIXME: This is possible when we have `__askama_item.index` for example. However,
+        // can it happen in other cases?
+        //
+        // Also, it's super annoying in case there is a keyword...
+        let expr = TokenStream::from_str(resolved).unwrap();
+        quote_into!(buf, span, { #expr });
+    } else {
+        for (idx, name) in resolved.split('.').enumerate() {
+            if idx > 0 {
+                buf.write_token(Token![.], span);
+            }
+            buf.write_field(name, span);
         }
-        buf.write_field(name, span);
     }
 }

testing/tests/macro.rs

@@ -646,3 +646,26 @@ fn test_macro_raw_lifetime() {
 
     assert_eq!(Foo.render().unwrap(), "ok");
 }
+
+// Because of how we generated "resolved variables", we had it in two parts:
+// first the `(__askama_item` and then `index0)` (with the `.` generated in the
+// middle). Of course, doing that in two passes went horribly wrong as you cannot
+// generate `Ident` from that.
+#[test]
+fn test_loop_variable_in_macro_call() {
+    #[derive(Template)]
+    #[template(
+        source = r#"
+{%- macro w(lol) -%}
+y: {{ lol -}}
+{% endmacro -%}
+
+{%- for x in &[0] -%}
+{%- call w(loop.index) %}{% endcall -%}
+{% endfor %}"#,
+        ext = "txt"
+    )]
+    struct Foo;
+
+    assert_eq!(Foo.render().unwrap(), "y: 1");
+}

testing/tests/ui/filter-invocation-invalid-arguments.stderr

@@ -57,7 +57,16 @@ help: the trait `ValidFilterInvocation` is not implemented for `req1<'_>`
    |
 12 |     #[askama::filter_fn]
    |     ^^^^^^^^^^^^^^^^^^^^
-   = help: the trait `ValidFilterInvocation` is implemented for `req1<'_, true>`
+help: the trait `ValidFilterInvocation` is implemented for `req1<'_, true>`
+  --> tests/ui/filter-invocation-invalid-arguments.rs:13:16
+   |
+13 |       pub fn req1(
+   |  ________________^
+14 | |         input: impl std::fmt::Display,
+15 | |         _env: &dyn askama::Values,
+16 | |         req1: usize,
+17 | |     ) -> askama::Result<String> {
+   | |_____^
    = note: this error originates in the derive macro `Template` which comes from the expansion of the attribute macro `askama::filter_fn` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0599]: no method named `execute` found for struct `req1<'_>` in the current scope
@@ -90,9 +99,13 @@ error[E0277]: Argument at position 1 is invalid on filter req1<'_>. Too many arg
 36 | #[derive(Template)]
    |          ^^^^^^^^ Filter function
    |
-   = help: the trait `ValidArgIdx<1>` is not implemented for `req1<'_>`
-           but trait `ValidArgIdx<0>` is implemented for it
-   = note: this error originates in the derive macro `Template` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: the trait `ValidArgIdx<1>` is not implemented for `req1<'_>`
+      but trait `ValidArgIdx<0>` is implemented for it
+  --> tests/ui/filter-invocation-invalid-arguments.rs:12:5
+   |
+12 |     #[askama::filter_fn]
+   |     ^^^^^^^^^^^^^^^^^^^^
+   = note: this error originates in the derive macro `Template` which comes from the expansion of the attribute macro `askama::filter_fn` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error[E0599]: no method named `with_req2` found for struct `req1<'filter, REQUIRED_ARG_FLAG_0>` in the current scope
   --> tests/ui/filter-invocation-invalid-arguments.rs:40:10

testing/tests/ui/truncate.stderr

@@ -20,11 +20,19 @@ error[E0277]: the trait bound `usize: TryFrom<f32>` is not satisfied
 9 | #[derive(Template)]
   |          ^^^^^^^^ the trait `From<f32>` is not implemented for `usize`
   |
-  = help: the following other types implement trait `From<T>`:
-            `usize` implements `From<bool>`
-            `usize` implements `From<std::ptr::Alignment>`
-            `usize` implements `From<u16>`
-            `usize` implements `From<u8>`
+help: the following other types implement trait `From<T>`
+ --> $RUST/core/src/convert/num.rs
+  |
+  = note: `usize` implements `From<bool>`
+ ::: $RUST/core/src/convert/num.rs
+  |
+  = note: `usize` implements `From<u8>`
+ ::: $RUST/core/src/convert/num.rs
+  |
+  = note: `usize` implements `From<u16>`
+ --> $RUST/core/src/ptr/alignment.rs
+  |
+  = note: `usize` implements `From<std::ptr::Alignment>`
   = note: required for `f32` to implement `Into<usize>`
   = note: required for `usize` to implement `TryFrom<f32>`
-  = note: this error originates in the derive macro `Template` (in Nightly builds, run with -Z macro-backtrace for more info)
+  = note: this error originates in the derive macro `Template` which comes from the expansion of the macro `impl_from` (in Nightly builds, run with -Z macro-backtrace for more info)