parser: tell user proper keyword to end node

rinja_parser/src/node.rs

@@ -3,7 +3,7 @@ use std::str;
 use nom::branch::alt;
 use nom::bytes::complete::{tag, take_till};
 use nom::character::complete::char;
-use nom::combinator::{complete, consumed, cut, eof, map, not, opt, peek, recognize, value};
+use nom::combinator::{complete, consumed, cut, eof, fail, map, not, opt, peek, recognize, value};
 use nom::error::ErrorKind;
 use nom::error_position;
 use nom::multi::{many0, many1, separated_list0};
@@ -377,7 +377,7 @@ impl<'a> Loop<'a> {
                             |i| s.tag_block_start(i),
                             opt(Whitespace::parse),
                             opt(else_block),
-                            ws(keyword("endfor")),
+                            end_node("for", "endfor"),
                             opt(Whitespace::parse),
                         ))),
                     ))),
@@ -449,7 +449,7 @@ impl<'a> Macro<'a> {
             cut(tuple((
                 |i| s.tag_block_start(i),
                 opt(Whitespace::parse),
-                ws(keyword("endmacro")),
+                end_node("macro", "endmacro"),
                 cut(preceded(
                     opt(|before| {
                         let (after, end_name) = ws(identifier)(before)?;
@@ -525,7 +525,7 @@ impl<'a> FilterBlock<'a> {
             cut(tuple((
                 |i| s.tag_block_start(i),
                 opt(Whitespace::parse),
-                ws(keyword("endfilter")),
+                end_node("filter", "endfilter"),
                 opt(Whitespace::parse),
             ))),
         )));
@@ -645,7 +645,7 @@ impl<'a> Match<'a> {
                         cut(tuple((
                             ws(|i| s.tag_block_start(i)),
                             opt(Whitespace::parse),
-                            ws(keyword("endmatch")),
+                            end_node("match", "endmatch"),
                             opt(Whitespace::parse),
                         ))),
                     ))),
@@ -699,7 +699,7 @@ impl<'a> BlockDef<'a> {
             cut(tuple((
                 |i| s.tag_block_start(i),
                 opt(Whitespace::parse),
-                ws(keyword("endblock")),
+                end_node("block", "endblock"),
                 cut(tuple((
                     opt(|before| {
                         let (after, end_name) = ws(identifier)(before)?;
@@ -806,7 +806,7 @@ impl<'a> Raw<'a> {
         let endraw = tuple((
             |i| s.tag_block_start(i),
             opt(Whitespace::parse),
-            ws(keyword("endraw")),
+            ws(keyword("endraw")), // sic: ignore `{% end %}` in raw blocks
             opt(Whitespace::parse),
             peek(|i| s.tag_block_end(i)),
         ));
@@ -888,7 +888,7 @@ impl<'a> If<'a> {
                     cut(tuple((
                         |i| s.tag_block_start(i),
                         opt(Whitespace::parse),
-                        ws(keyword("endif")),
+                        end_node("if", "endif"),
                         opt(Whitespace::parse),
                     ))),
                 ))),
@@ -1057,6 +1057,25 @@ impl<'a> Comment<'a> {
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Ws(pub Option<Whitespace>, pub Option<Whitespace>);
 
+fn end_node<'a, 'g: 'a>(
+    node: &'g str,
+    expected: &'g str,
+) -> impl Fn(&'a str) -> ParseResult<'a> + 'g {
+    move |start| {
+        let (i, actual) = ws(identifier)(start)?;
+        if actual == expected {
+            Ok((i, actual))
+        } else if actual == "end" {
+            Err(nom::Err::Failure(ErrorContext::new(
+                format!("expected `{expected}` to terminate `{node}` node, found `{actual}`"),
+                start,
+            )))
+        } else {
+            fail(start)
+        }
+    }
+}
+
 #[doc(hidden)]
 pub const MAX_KW_LEN: usize = 8;
 const MAX_REPL_LEN: usize = MAX_KW_LEN + 2;

testing/tests/ui/wrong-end.stderr

@@ -1,46 +1,46 @@
-error: failed to parse template source
- --> <source attribute>:1:24
-       "end %}"
+error: expected `endfor` to terminate `for` node, found `end`
+ --> <source attribute>:1:23
+       " end %}"
  --> tests/ui/wrong-end.rs:4:21
   |
 4 | #[template(source = "{% for _ in 1..=10 %}{% end %}", ext = "txt")]
   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: failed to parse template source
- --> <source attribute>:1:21
-       "end %}"
+error: expected `endmacro` to terminate `macro` node, found `end`
+ --> <source attribute>:1:20
+       " end %}"
  --> tests/ui/wrong-end.rs:8:21
   |
 8 | #[template(source = "{% macro test() %}{% end %}", ext = "txt")]
   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: failed to parse template source
- --> <source attribute>:1:21
-       "end %}"
+error: expected `endfilter` to terminate `filter` node, found `end`
+ --> <source attribute>:1:20
+       " end %}"
   --> tests/ui/wrong-end.rs:12:21
    |
 12 | #[template(source = "{% filter upper %}{% end %}", ext = "txt")]
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: failed to parse template source
+error: expected `endmatch` to terminate `match` node, found `end`
  --> <source attribute>:1:30
        "end %}"
   --> tests/ui/wrong-end.rs:16:21
    |
 16 | #[template(source = "{% match () %}{% when () %}{% end %}", ext = "txt")]
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: failed to parse template source
- --> <source attribute>:1:19
-       "end %}"
+error: expected `endblock` to terminate `block` node, found `end`
+ --> <source attribute>:1:18
+       " end %}"
   --> tests/ui/wrong-end.rs:20:21
    |
 20 | #[template(source = "{% block body %}{% end %}", ext = "txt")]
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: failed to parse template source
- --> <source attribute>:1:16
-       "end %}"
+error: expected `endif` to terminate `if` node, found `end`
+ --> <source attribute>:1:15
+       " end %}"
   --> tests/ui/wrong-end.rs:24:21
    |
 24 | #[template(source = "{% if true %}{% end %}", ext = "txt")]