Merge pull request #42 from GuillaumeGomez/top-level-nodes-errors

Generate better errors for top level nodes

Author: GuillaumeGomez

rinja_derive/src/heritage.rs

@@ -76,26 +76,25 @@ impl Context<'_> {
         while let Some(nodes) = nested.pop() {
             for n in nodes {
                 match n {
-                    Node::Extends(e) if top => match extends {
-                        Some(_) => {
-                            return Err(CompileError::no_file_info("multiple extend blocks found"))
+                    Node::Extends(e) => {
+                        ensure_top(top, e, path, parsed, "extends")?;
+                        if extends.is_some() {
+                            return Err(CompileError::new(
+                                "multiple extend blocks found",
+                                Some(FileInfo::of(e, path, parsed)),
+                            ));
                         }
-                        None => {
-                            extends = Some(config.find_template(e.path, Some(path))?);
-                        }
-                    },
-                    Node::Macro(m) if top => {
+                        extends = Some(config.find_template(e.path, Some(path))?);
+                    }
+                    Node::Macro(m) => {
+                        ensure_top(top, m, path, parsed, "macro")?;
                         macros.insert(m.name, &**m);
                     }
-                    Node::Import(import) if top => {
+                    Node::Import(import) => {
+                        ensure_top(top, import, path, parsed, "import")?;
                         let path = config.find_template(import.path, Some(path))?;
                         imports.insert(import.scope, path);
                     }
-                    Node::Extends(_) | Node::Macro(_) | Node::Import(_) if !top => {
-                        return Err(CompileError::no_file_info(
-                            "extends, macro or import blocks not allowed below top level",
-                        ));
-                    }
                     Node::BlockDef(b) => {
                         blocks.insert(b.name, &**b);
                         nested.push(&b.nodes);
@@ -132,16 +131,26 @@ impl Context<'_> {
     }
 
     pub(crate) fn generate_error<T>(&self, msg: &str, node: &WithSpan<'_, T>) -> CompileError {
-        match self.path {
-            Some(path) => CompileError::new(
-                msg,
-                Some(FileInfo::new(
-                    path,
-                    Some(self.parsed.source()),
-                    Some(node.span()),
-                )),
-            ),
-            None => CompileError::new(msg, None),
-        }
+        CompileError::new(
+            msg,
+            self.path.map(|path| FileInfo::of(node, path, self.parsed)),
+        )
+    }
+}
+
+fn ensure_top<T>(
+    top: bool,
+    node: &WithSpan<'_, T>,
+    path: &Path,
+    parsed: &Parsed,
+    kind: &str,
+) -> Result<(), CompileError> {
+    if top {
+        Ok(())
+    } else {
+        Err(CompileError::new(
+            format!("`{kind}` blocks are not allowed below top level"),
+            Some(FileInfo::of(node, path, parsed)),
+        ))
     }
 }

rinja_derive/src/lib.rs

@@ -16,7 +16,7 @@ use config::{read_config_file, Config};
 use generator::{Generator, MapChain};
 use heritage::{Context, Heritage};
 use input::{Print, TemplateArgs, TemplateInput};
-use parser::{generate_error_info, strip_common, ErrorInfo, ParseError};
+use parser::{generate_error_info, strip_common, ErrorInfo, ParseError, Parsed, WithSpan};
 use proc_macro2::{Span, TokenStream};
 
 #[cfg(not(feature = "__standalone"))]
@@ -138,7 +138,7 @@ struct CompileError {
 }
 
 impl CompileError {
-    fn new<S: fmt::Display>(msg: S, file_info: Option<FileInfo<'_, '_, '_>>) -> Self {
+    fn new<S: fmt::Display>(msg: S, file_info: Option<FileInfo<'_>>) -> Self {
         let msg = match file_info {
             Some(file_info) => format!("{msg}{file_info}"),
             None => msg.to_string(),
@@ -178,23 +178,31 @@ impl From<ParseError> for CompileError {
     }
 }
 
-struct FileInfo<'a, 'b, 'c> {
+struct FileInfo<'a> {
     path: &'a Path,
-    source: Option<&'b str>,
-    node_source: Option<&'c str>,
+    source: Option<&'a str>,
+    node_source: Option<&'a str>,
 }
 
-impl<'a, 'b, 'c> FileInfo<'a, 'b, 'c> {
-    fn new(path: &'a Path, source: Option<&'b str>, node_source: Option<&'c str>) -> Self {
+impl<'a> FileInfo<'a> {
+    fn new(path: &'a Path, source: Option<&'a str>, node_source: Option<&'a str>) -> Self {
         Self {
             path,
             source,
             node_source,
         }
     }
+
+    fn of<T>(node: &WithSpan<'a, T>, path: &'a Path, parsed: &'a Parsed) -> Self {
+        Self {
+            path,
+            source: Some(parsed.source()),
+            node_source: Some(node.span()),
+        }
+    }
 }
 
-impl<'a, 'b, 'c> fmt::Display for FileInfo<'a, 'b, 'c> {
+impl fmt::Display for FileInfo<'_> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match (self.source, self.node_source) {
             (Some(source), Some(node_source)) => {

rinja_parser/src/lib.rs

@@ -147,7 +147,7 @@ impl<'a, T> WithSpan<'a, T> {
         Self { inner, span }
     }
 
-    pub fn span(&self) -> &str {
+    pub fn span(&self) -> &'a str {
         self.span
     }
 }

testing/tests/ui/blocks_below_top_level.rs

@@ -0,0 +1,29 @@
+use rinja::Template;
+
+#[derive(Template)]
+#[template(source = r#"
+{% block bla %}
+{% extends "bla.txt" %}
+{% endblock %}
+"#, ext = "txt")]
+struct MyTemplate1;
+
+#[derive(Template)]
+#[template(source = r#"
+{% block bla %}
+{% macro bla() %}
+{% endmacro %}
+{% endblock %}
+"#, ext = "txt")]
+struct MyTemplate2;
+
+#[derive(Template)]
+#[template(source = r#"
+{% block bla %}
+{% import "bla.txt" as blue %}
+{% endblock %}
+"#, ext = "txt")]
+struct MyTemplate3;
+
+fn main() {
+}

testing/tests/ui/blocks_below_top_level.stderr

@@ -0,0 +1,29 @@
+error: `extends` blocks are not allowed below top level
+ --> MyTemplate1.txt:3:2
+       " extends \"bla.txt\" %}\n{% endblock %}\n"
+ --> tests/ui/blocks_below_top_level.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: `macro` blocks are not allowed below top level
+ --> MyTemplate2.txt:3:2
+       " macro bla() %}\n{% endmacro %}\n{% endblo"...
+  --> tests/ui/blocks_below_top_level.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)
+
+error: `import` blocks are not allowed below top level
+ --> MyTemplate3.txt:3:2
+       " import \"bla.txt\" as blue %}\n{% endblock"...
+  --> tests/ui/blocks_below_top_level.rs:20:10
+   |
+20 | #[derive(Template)]
+   |          ^^^^^^^^
+   |
+   = note: this error originates in the derive macro `Template` (in Nightly builds, run with -Z macro-backtrace for more info)

testing/tests/ui/multiple_extends.rs

@@ -0,0 +1,10 @@
+use rinja::Template;
+
+#[derive(Template)]
+#[template(source = r#"
+{% extends "let.html" %}
+{% extends "foo.html" %}
+"#, ext = "txt")]
+struct MyTemplate4;
+
+fn main() {}

testing/tests/ui/multiple_extends.stderr

@@ -0,0 +1,9 @@
+error: multiple extend blocks found
+ --> MyTemplate4.txt:3:2
+       " extends \"foo.html\" %}\n"
+ --> tests/ui/multiple_extends.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)