feat! collect errors from diagram rendering

The errors are always rendered into the document. The caller can get
them with the DiagramFilter::errors method and can decide what to do
if there are any.

This also changes the function signature for
DiagramFilter::error_block, which is SemVer incompatible.

Sponsored-by: author

1 files changed, 25 insertions, 7 deletions

diff --git a/src/lib.rs b/src/lib.rs
index c7c3bc5..0f7b2a1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -32,6 +32,7 @@ pub struct DiagramFilter {
     roadmap_width: usize,
     java_path: PathBuf,
     plantuml_jar: PathBuf,
+    errors: Vec<DiagramError>,
 }
 
 /// Possible errors for diagram filtering.
@@ -81,6 +82,7 @@ impl Default for DiagramFilter {
             roadmap_width: 50,
             java_path: PathBuf::from("java"),
             plantuml_jar: PathBuf::from("/usr/share/plantuml/plantuml.jar"),
+            errors: vec![],
         }
     }
 }
@@ -90,6 +92,10 @@ impl DiagramFilter {
         Self::default()
     }
 
+    pub fn errors(&self) -> &[DiagramError] {
+        &self.errors
+    }
+
     pub fn dot_path<P>(&mut self, path: P) -> &mut Self
     where
         P: AsRef<Path>,
@@ -124,7 +130,7 @@ impl DiagramFilter {
         doc
     }
 
-    fn error_block(&self, error: DiagramError) -> Block {
+    fn error_block(&self, error: &DiagramError) -> Block {
         let msg = Inline::Str(format!("ERROR: {}", error.to_string()));
         let msg = vec![Inline::Strong(vec![msg])];
         Block::Para(msg)
@@ -228,12 +234,12 @@ fn filter_via(
             } else {
                 String::from("terminated by signal")
             };
-            let stderr = String::from_utf8_lossy(&output.stderr);
+            let stderr = String::from_utf8_lossy(&output.stderr).into_owned();
             Err(DiagramError::HelperFailed(
                 name.to_string(),
                 argv0.to_path_buf(),
                 status,
-                stderr.into_owned(),
+                stderr,
             ))
         }
     } else {
@@ -255,19 +261,31 @@ impl MutVisitor for DiagramFilter {
         match block {
             Block::CodeBlock((_id, classes, _kv), text) => match DiagramKind::from(classes) {
                 DiagramKind::GraphvizDot => match self.dot_to_svg(text) {
-                    Err(err) => *block = self.error_block(err),
+                    Err(err) => {
+                        *block = self.error_block(&err);
+                        self.errors.push(err);
+                    }
                     Ok(svg) => *block = self.svg_block(&svg),
                 },
                 DiagramKind::Roadmap => match self.roadmap_to_svg(text) {
-                    Err(err) => *block = self.error_block(err),
+                    Err(err) => {
+                        *block = self.error_block(&err);
+                        self.errors.push(err);
+                    }
                     Ok(svg) => *block = self.svg_block(&svg),
                 },
                 DiagramKind::Plantuml => match self.plantuml_to_svg(text) {
-                    Err(err) => *block = self.error_block(err),
+                    Err(err) => {
+                        *block = self.error_block(&err);
+                        self.errors.push(err);
+                    }
                     Ok(svg) => *block = self.svg_block(&svg),
                 },
                 DiagramKind::Pikchr => match self.pikchr_to_svg(text, None) {
-                    Err(err) => *block = self.error_block(err),
+                    Err(err) => {
+                        *block = self.error_block(&err);
+                        self.errors.push(err);
+                    }
                     Ok(svg) => *block = self.svg_block(&svg),
                 },
                 DiagramKind::Svg => *block = self.svg_block(text.as_bytes()),