Enable multiple footer annotations

Author: Zibi Braniecki

examples/footer.rs

@@ -10,14 +10,14 @@ fn main() {
             id: Some("E0308".to_string()),
             annotation_type: AnnotationType::Error,
         }),
-        footer: Some(Annotation {
+        footer: vec![Annotation {
             label: Some(
                 "expected type: `snippet::Annotation`\n   found type: `__&__snippet::Annotation`"
                     .to_string(),
             ),
             id: None,
             annotation_type: AnnotationType::Note,
-        }),
+        }],
         slices: vec![Slice {
             source: "        slices: vec![\"A\",".to_string(),
             line_start: 13,

examples/format.rs

@@ -49,7 +49,7 @@ fn main() {
             id: Some("E0308".to_string()),
             annotation_type: AnnotationType::Error,
         }),
-        footer: None,
+        footer: vec![],
     };
 
     println!("{}", DisplayList::from(snippet));

examples/multislice.rs

@@ -10,7 +10,7 @@ fn main() {
             id: None,
             annotation_type: AnnotationType::Error,
         }),
-        footer: None,
+        footer: vec![],
         slices: vec![
             Slice {
                 source: "Foo".to_string(),

src/display_list.rs

@@ -358,11 +358,12 @@ impl From<Snippet> for DisplayList {
             body.append(&mut format_slice(
                 &slice,
                 slice_idx == 0,
-                snippet.footer.is_some(),
+                !snippet.footer.is_empty(),
             ));
             slice_idx += 1;
         }
-        if let Some(annotation) = snippet.footer {
+
+        for annotation in snippet.footer {
             body.push(format_annotation(&annotation));
         }
 

src/format.rs

@@ -97,19 +97,12 @@ impl DisplayListFormatting for Formatter {
                     .split_first()
                 {
                     let indent = prefix.len() + name.len() + 2;
-                    writeln!(
-                        f,
-                        "{}{}{}",
-                        prefix,
-                        name,
-                        format!(": {}", first)
-                    )?;
+                    writeln!(f, "{}{}{}", prefix, name, format!(": {}", first))?;
                     for line in rest {
                         writeln!(f, "{}{}", " ".repeat(indent), format!("{}", line))?;
                     }
                 }
                 Ok(())
-                
             }
             DisplayLine::Origin {
                 path,

src/snippet.rs

@@ -2,7 +2,7 @@
 #[derive(Debug, Clone)]
 pub struct Snippet {
     pub title: Option<Annotation>,
-    pub footer: Option<Annotation>,
+    pub footer: Vec<Annotation>,
     pub slices: Vec<Slice>,
 }
 

tests/snippet/mod.rs

@@ -12,9 +12,9 @@ pub struct SnippetDef {
     #[serde(deserialize_with = "deserialize_annotation")]
     #[serde(default)]
     pub title: Option<Annotation>,
-    #[serde(deserialize_with = "deserialize_annotation")]
+    #[serde(deserialize_with = "deserialize_annotations")]
     #[serde(default)]
-    pub footer: Option<Annotation>,
+    pub footer: Vec<Annotation>,
     #[serde(deserialize_with = "deserialize_slices")]
     pub slices: Vec<Slice>,
 }
@@ -41,6 +41,17 @@ where
         .map(|opt_wrapped: Option<Wrapper>| opt_wrapped.map(|wrapped: Wrapper| wrapped.0))
 }
 
+fn deserialize_annotations<'de, D>(deserializer: D) -> Result<Vec<Annotation>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    #[derive(Deserialize)]
+    struct Wrapper(#[serde(with = "AnnotationDef")] Annotation);
+
+    let v = Vec::deserialize(deserializer)?;
+    Ok(v.into_iter().map(|Wrapper(a)| a).collect())
+}
+
 #[derive(Deserialize)]
 #[serde(remote = "Slice")]
 pub struct SliceDef {