Improve macro call arguments mismatch errors

rinja_derive/src/generator/node.rs

@@ -1,4 +1,5 @@
 use std::borrow::Cow;
+use std::collections::HashSet;
 use std::collections::hash_map::{Entry, HashMap};
 use std::fmt::Write;
 use std::mem;
@@ -1421,33 +1422,73 @@ fn macro_call_ensure_arg_count(
     def: &Macro<'_>,
     ctx: &Context<'_>,
 ) -> Result<(), CompileError> {
-    if call.args.len() == def.args.len() {
-        // exactly enough arguments were provided
-        return Ok(());
+    if call.args.len() > def.args.len() {
+        return Err(ctx.generate_error(
+            format_args!(
+                "macro `{}` expected {} argument{}, found {}",
+                def.name,
+                def.args.len(),
+                if def.args.len() > 1 { "s" } else { "" },
+                call.args.len(),
+            ),
+            call.span(),
+        ));
     }
-
-    let nb_default_args = def
-        .args
-        .iter()
-        .rev()
-        .take_while(|(_, default_value)| default_value.is_some())
-        .count();
-    if call.args.len() < def.args.len() && call.args.len() >= def.args.len() - nb_default_args {
-        // all missing arguments have a default value, and there weren't too many args
-        return Ok(());
+    // First we list of arguments position then we remove them one by one.
+    let mut args = (0..def.args.len()).collect::<HashSet<_>>();
+    for (pos, arg) in call.args.iter().enumerate() {
+        let pos = match **arg {
+            Expr::NamedArgument(name, ..) => {
+                def.args.iter().position(|(arg_name, _)| *arg_name == name)
+            }
+            _ => Some(pos),
+        };
+        if let Some(pos) = pos {
+            if !args.remove(&pos) {
+                // This argument was already passed, so error.
+                return Err(ctx.generate_error(
+                    format_args!(
+                        "argument `{}` is passed more than once when calling macro `{}`",
+                        def.args[pos].0, def.name,
+                    ),
+                    call.span(),
+                ));
+            }
+        }
     }
 
-    // either too many or not enough arguments were provided
-    let (expected_args, extra) = match nb_default_args {
-        0 => (def.args.len(), ""),
-        _ => (nb_default_args, "at least "),
+    // Now we need to filter out arguments with default value.
+    let args = args
+        .into_iter()
+        .filter(|pos| def.args[*pos].1.is_none())
+        .collect::<Vec<_>>();
+    let (extra, error) = match args.len() {
+        0 => return Ok(()),
+        1 => ("", format!("`{}`", def.args[0].0)),
+        2 => ("s", format!("`{}` and `{}`", def.args[0].0, def.args[1].0)),
+        _ => {
+            let mut error_s =
+                args.iter()
+                    .take(args.len() - 2)
+                    .fold(String::new(), |mut acc, arg| {
+                        if !acc.is_empty() {
+                            acc.push_str(", ");
+                        }
+                        acc.push_str(&format!("`{}`", def.args[*arg].0));
+                        acc
+                    });
+            error_s.push_str(&format!(
+                " and `{}`",
+                def.args[*args.last().expect("no last args")].0
+            ));
+            ("s", error_s)
+        }
     };
+
     Err(ctx.generate_error(
         format_args!(
-            "macro {:?} expected {extra}{expected_args} argument{}, found {}",
-            def.name,
-            if expected_args != 1 { "s" } else { "" },
-            call.args.len(),
+            "missing argument{extra} when calling macro `{}`: {error}",
+            def.name
         ),
         call.span(),
     ))

testing/tests/ui/macro.rs

@@ -39,5 +39,27 @@ struct NoClosingParen3;
 #[template(source = "{% macro thrice(a, b, c = %}{% endmacro %}", ext = "html")]
 struct NoClosingParen4;
 
+#[derive(rinja::Template)]
+#[template(
+    source = r#"
+        {% macro example(name, value, current, label="", id="") %}
+        {% endmacro %}
+        {% call example(name="name", value="") %}
+    "#,
+    ext = "txt"
+)]
+struct WrongNumberOfParams;
+
+#[derive(rinja::Template)]
+#[template(
+    source = r#"
+        {% macro example(name, value, arg=12) %}
+        {% endmacro %}
+        {% call example(0, name="name", value="") %}
+    "#,
+    ext = "txt"
+)]
+struct DuplicatedArg;
+
 fn main() {
 }

testing/tests/ui/macro.stderr

@@ -1,4 +1,4 @@
-error: macro "thrice" expected 1 argument, found 2
+error: macro `thrice` expected 1 argument, found 2
  --> InvalidNumberOfArgs.html:5:2
        "- call thrice(2, 3) -%}"
  --> tests/ui/macro.rs:4:21
@@ -11,7 +11,7 @@ error: macro "thrice" expected 1 argument, found 2
 8 | | {%- call thrice(2, 3) -%}", ext = "html")]
   | |__________________________^
 
-error: macro "thrice" expected 2 arguments, found 0
+error: missing arguments when calling macro `thrice`: `param` and `param2`
  --> InvalidNumberOfArgs2.html:5:2
        "- call thrice() -%}"
   --> tests/ui/macro.rs:12:21
@@ -24,7 +24,7 @@ error: macro "thrice" expected 2 arguments, found 0
 16 | | {%- call thrice() -%}", ext = "html")]
    | |______________________^
 
-error: macro "thrice" expected 0 arguments, found 2
+error: macro `thrice` expected 0 argument, found 2
  --> InvalidNumberOfArgs3.html:4:2
        "- call thrice(1, 2) -%}"
   --> tests/ui/macro.rs:20:21
@@ -67,3 +67,29 @@ error: expected `)` to close macro argument list
    |
 39 | #[template(source = "{% macro thrice(a, b, c = %}{% endmacro %}", ext = "html")]
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: missing argument when calling macro `example`: `name`
+ --> WrongNumberOfParams.txt:4:10
+       " call example(name=\"name\", value=\"\") %}\n    "
+  --> tests/ui/macro.rs:44:14
+   |
+44 |       source = r#"
+   |  ______________^
+45 | |         {% macro example(name, value, current, label="", id="") %}
+46 | |         {% endmacro %}
+47 | |         {% call example(name="name", value="") %}
+48 | |     "#,
+   | |______^
+
+error: argument `name` is passed more than once when calling macro `example`
+ --> DuplicatedArg.txt:4:10
+       " call example(0, name=\"name\", value=\"\") %}\n    "
+  --> tests/ui/macro.rs:55:14
+   |
+55 |       source = r#"
+   |  ______________^
+56 | |         {% macro example(name, value, arg=12) %}
+57 | |         {% endmacro %}
+58 | |         {% call example(0, name="name", value="") %}
+59 | |     "#,
+   | |______^

testing/tests/ui/macro_default_value.stderr

@@ -1,4 +1,4 @@
-error: macro "thrice" expected at least 1 argument, found 0
+error: missing argument when calling macro `thrice`: `param1`
  --> InvalidDefault1.html:4:2
        "- call thrice() -%}"
  --> tests/ui/macro_default_value.rs:4:21
@@ -10,7 +10,7 @@ error: macro "thrice" expected at least 1 argument, found 0
 7 | | {%- call thrice() -%}", ext = "html")]
   | |______________________^
 
-error: macro "thrice" expected at least 1 argument, found 3
+error: macro `thrice` expected 2 arguments, found 3
  --> InvalidDefault2.html:4:2
        "- call thrice(1, 2, 3) -%}"
   --> tests/ui/macro_default_value.rs:11:21

testing/tests/ui/macro_named_argument.stderr

@@ -1,4 +1,4 @@
-error: no argument named `param3` in macro "thrice"
+error: missing argument when calling macro `thrice`: `param1`
  --> InvalidNamedArg.html:5:2
        "- call thrice(param1=2, param3=3) -%}"
  --> tests/ui/macro_named_argument.rs:4:21
@@ -49,7 +49,7 @@ error: named arguments must always be passed last
 33 | | {%- call thrice(param1=2, 3) -%}", ext = "html")]
    | |_________________________________^
 
-error: `param1` is passed more than once
+error: argument `param1` is passed more than once when calling macro `thrice`
  --> InvalidNamedArg5.html:4:2
        "- call thrice(3, param1=2) -%}"
   --> tests/ui/macro_named_argument.rs:38:21