Add some #[must_use] and other small things brought up from linting

Author: kaleidawave

codespan-reporting/src/diagnostic.rs

@@ -90,6 +90,7 @@ impl<FileId> Label<FileId> {
     }
 
     /// Add a message to the diagnostic.
+    #[must_use]
     pub fn with_message(mut self, message: impl Display) -> Label<FileId> {
         self.message = message.to_string();
         self
@@ -137,63 +138,73 @@ impl<FileId> Diagnostic<FileId> {
     /// Create a new diagnostic with a severity of [`Severity::Bug`].
     ///
     /// [`Severity::Bug`]: Severity::Bug
+    #[must_use]
     pub fn bug() -> Diagnostic<FileId> {
         Diagnostic::new(Severity::Bug)
     }
 
     /// Create a new diagnostic with a severity of [`Severity::Error`].
     ///
     /// [`Severity::Error`]: Severity::Error
+    #[must_use]
     pub fn error() -> Diagnostic<FileId> {
         Diagnostic::new(Severity::Error)
     }
 
     /// Create a new diagnostic with a severity of [`Severity::Warning`].
     ///
     /// [`Severity::Warning`]: Severity::Warning
+    #[must_use]
     pub fn warning() -> Diagnostic<FileId> {
         Diagnostic::new(Severity::Warning)
     }
 
     /// Create a new diagnostic with a severity of [`Severity::Note`].
     ///
     /// [`Severity::Note`]: Severity::Note
+    #[must_use]
     pub fn note() -> Diagnostic<FileId> {
         Diagnostic::new(Severity::Note)
     }
 
     /// Create a new diagnostic with a severity of [`Severity::Help`].
     ///
     /// [`Severity::Help`]: Severity::Help
+    #[must_use]
     pub fn help() -> Diagnostic<FileId> {
         Diagnostic::new(Severity::Help)
     }
 
     /// Set the error code of the diagnostic.
+    #[must_use]
     pub fn with_code(mut self, code: impl Display) -> Diagnostic<FileId> {
         self.code = Some(code.to_string());
         self
     }
 
     /// Set the message of the diagnostic.
+    #[must_use]
     pub fn with_message(mut self, message: impl Display) -> Diagnostic<FileId> {
         self.message = message.to_string();
         self
     }
 
     /// Add a label to the diagnostic.
+    #[must_use]
     pub fn with_label(mut self, label: Label<FileId>) -> Diagnostic<FileId> {
         self.labels.push(label);
         self
     }
 
     /// Add some labels to the diagnostic.
+    #[must_use]
     pub fn with_labels(mut self, mut labels: Vec<Label<FileId>>) -> Diagnostic<FileId> {
         self.labels.append(&mut labels);
         self
     }
 
     /// Add some labels to the diagnostic.
+    #[must_use]
     pub fn with_labels_iter(
         mut self,
         labels: impl IntoIterator<Item = Label<FileId>>,
@@ -204,18 +215,21 @@ impl<FileId> Diagnostic<FileId> {
 
     /// Add a note to the diagnostic.
     #[allow(clippy::needless_pass_by_value)]
+    #[must_use]
     pub fn with_note(mut self, note: impl ToString) -> Diagnostic<FileId> {
         self.notes.push(note.to_string());
         self
     }
 
     /// Add some notes to the diagnostic.
+    #[must_use]
     pub fn with_notes(mut self, mut notes: Vec<String>) -> Diagnostic<FileId> {
         self.notes.append(&mut notes);
         self
     }
 
     /// Add some notes to the diagnostic.
+    #[must_use]
     pub fn with_notes_iter(
         mut self,
         notes: impl IntoIterator<Item = String>,

codespan-reporting/src/files.rs

@@ -224,6 +224,7 @@ pub struct Location {
 /// assert_eq!(files::column_index(source, 2..13, 2 + 11), 3);
 /// assert_eq!(files::column_index(source, 2..13, 2 + 12), 3);
 /// ```
+#[must_use]
 pub fn column_index(source: &str, line_range: Range<usize>, byte_index: usize) -> usize {
     let end_index = core::cmp::min(byte_index, core::cmp::min(line_range.end, source.len()));
 
@@ -383,6 +384,7 @@ where
     Source: AsRef<str>,
 {
     /// Create a new files database.
+    #[must_use]
     pub fn new() -> SimpleFiles<Name, Source> {
         SimpleFiles { files: Vec::new() }
     }

codespan-reporting/src/term/config.rs

@@ -152,6 +152,7 @@ pub mod styles {
 
     impl Styles {
         /// The style used to mark a header at a given severity.
+        #[must_use]
         pub fn header(&self, severity: Severity) -> &ColorSpec {
             match severity {
                 Severity::Bug => &self.header_bug,
@@ -162,23 +163,28 @@ pub mod styles {
             }
         }
 
+        #[must_use]
         pub fn header_message(&self) -> &ColorSpec {
             &self.header_message
         }
 
+        #[must_use]
         pub fn line_number(&self) -> &ColorSpec {
             &self.line_number
         }
 
+        #[must_use]
         pub fn note_bullet(&self) -> &ColorSpec {
             &self.note_bullet
         }
 
+        #[must_use]
         pub fn source_border(&self) -> &ColorSpec {
             &self.source_border
         }
 
         /// The style used to mark a primary or secondary label at a given severity.
+        #[must_use]
         pub fn label(&self, severity: Severity, label_style: LabelStyle) -> &ColorSpec {
             match (label_style, severity) {
                 (LabelStyle::Primary, Severity::Bug) => &self.primary_label_bug,
@@ -192,6 +198,7 @@ pub mod styles {
     }
 
     impl Styles {
+        #[must_use]
         pub fn no_color() -> Styles {
             Styles {
                 header_bug: ColorSpec::new(),
@@ -416,6 +423,7 @@ impl Default for Chars {
 
 impl Chars {
     /// A character set that uses Unicode box drawing characters.
+    #[must_use]
     pub fn box_drawing() -> Chars {
         Chars {
             snippet_start: "┌─".into(),
@@ -446,6 +454,7 @@ impl Chars {
     /// This is useful if your terminal's font does not support box drawing
     /// characters well and results in output that looks similar to rustc's
     /// diagnostic output.
+    #[must_use]
     pub fn ascii() -> Chars {
         Chars {
             snippet_start: "-->".into(),

codespan-reporting/src/term/renderer.rs

@@ -602,7 +602,7 @@ impl<'writer, 'config> Renderer<'writer, 'config> {
                 let current_label_style = single_labels
                     .iter()
                     .filter(|(_, range, _)| is_overlapping(range, &column_range))
-                    .map(|(label_style, _, _)| label_style.clone())
+                    .map(|(label_style, _, _)| *label_style)
                     .max_by_key(label_priority_key);
 
                 // Update writer style if necessary
@@ -925,7 +925,7 @@ impl<'writer, 'config> Renderer<'writer, 'config> {
             let column_range = metrics.byte_index..(metrics.byte_index + ch.len_utf8());
             let label_style = hanging_labels(single_labels, trailing_label)
                 .filter(|(_, range, _)| column_range.contains(&range.start))
-                .map(|(label_style, _, _)| label_style.clone())
+                .map(|(label_style, _, _)| *label_style)
                 .max_by_key(label_priority_key);
 
             let mut spaces = match label_style {
@@ -1199,6 +1199,7 @@ fn is_overlapping(range0: &Range<usize>, range1: &Range<usize>) -> bool {
 }
 
 /// For prioritizing primary labels over secondary labels when rendering carets.
+#[allow(clippy::trivially_copy_pass_by_ref)]
 fn label_priority_key(label_style: &LabelStyle) -> u8 {
     match label_style {
         LabelStyle::Secondary => 0,

codespan-reporting/src/term/views.rs

@@ -23,6 +23,7 @@ impl<'diagnostic, 'config, FileId> RichDiagnostic<'diagnostic, 'config, FileId>
 where
     FileId: Copy + PartialEq,
 {
+    #[must_use]
     pub fn new(
         diagnostic: &'diagnostic Diagnostic<FileId>,
         config: &'config Config,