Fix: edit error on checking out bounds spans

miette-derive/src/label.rs

@@ -4,14 +4,14 @@ use syn::{
     parenthesized,
     parse::{Parse, ParseStream},
     spanned::Spanned,
-    Token, Member,
+    Token,
 };
 
 use crate::{
     diagnostic::{DiagnosticConcreteArgs, DiagnosticDef},
     fmt::{self, Display},
     forward::WhichFn,
-    utils::{display_pat_members, gen_all_variants_with}, source_code::SourceCode,
+    utils::{display_pat_members, gen_all_variants_with},
 };
 
 pub struct Labels(Vec<Label>);
@@ -105,13 +105,6 @@ impl Labels {
     }
 
     pub(crate) fn gen_struct(&self, fields: &syn::Fields) -> Option<TokenStream> {
-        let sources = SourceCode::from_fields(fields).unwrap_or_else(|_| None);
-        let source : Option<Member>;
-        if let Some(SourceCode { source_code }) = sources {
-            source = Some(source_code);
-        } else {
-            source = None;
-        }
         let (display_pat, display_members) = display_pat_members(fields);
         let labels = self.0.iter().map(|highlight| {
             let Label { span, label, ty } = highlight;
@@ -120,15 +113,11 @@ impl Labels {
                 let (fmt, args) = display.expand_shorthand_cloned(&display_members);
                 quote! {
                     miette::macro_helpers::OptionalWrapper::<#ty>::new().to_option(&self.#span)
-                    .map(|#var| {
-                        if #source.len() < #var.len() + #var.offset() {
-                            panic!("invalid span, not shadowing the error message");
-                        };
-                        miette::LabeledSpan::new_with_span(
+                    .map(|#var| miette::LabeledSpan::new_with_span(
                             std::option::Option::Some(format!(#fmt #args)),
                             #var.clone(),
                         )
-                    })
+                    )
                 }
             } else {
                 quote! {

src/handlers/graphical.rs

@@ -315,7 +315,13 @@ impl GraphicalReportHandler {
                             source.read_span(label.inner(), self.context_lines, self.context_lines)
                         })
                         .collect::<Result<Vec<Box<dyn SpanContents<'_>>>, MietteError>>()
-                        .map_err(|_| fmt::Error)?;
+                        .map_err(|e| {
+                            if matches!(e,MietteError::OutOfBounds) {
+                                panic!("invalid span , OutOfBounds");
+                            } else {
+                                fmt::Error 
+                            }
+                        })?;
                     let mut contexts = Vec::new();
                     for (right, right_conts) in labels.iter().cloned().zip(contents.iter()) {
                         if contexts.is_empty() {

src/source_impls.rs

@@ -72,7 +72,7 @@ fn context_info<'a>(
         offset += 1;
     }
 
-    if offset >= (span.offset() + span.len()).saturating_sub(1) {
+    if offset >= (span.offset() + span.len()) {
         let starting_offset = before_lines_starts.first().copied().unwrap_or_else(|| {
             if context_lines_before == 0 {
                 span.offset()