combine_strs_with_missing_comments

Author: ding-young

src/attr.rs

@@ -11,8 +11,7 @@ use crate::config::IndentStyle;
 use crate::expr::rewrite_literal;
 use crate::lists::{definitive_tactic, itemize_list, write_list, ListFormatting, Separator};
 use crate::overflow;
-use crate::rewrite::RewriteErrorExt;
-use crate::rewrite::{Rewrite, RewriteContext, RewriteResult};
+use crate::rewrite::{Rewrite, RewriteContext, RewriteError, RewriteErrorExt, RewriteResult};
 use crate::shape::Shape;
 use crate::source_map::SpanUtils;
 use crate::types::{rewrite_path, PathContext};
@@ -218,9 +217,10 @@ fn rewrite_initial_doc_comments(
     context: &RewriteContext<'_>,
     attrs: &[ast::Attribute],
     shape: Shape,
-) -> Option<(usize, Option<String>)> {
+) -> Result<(usize, Option<String>), RewriteError> {
+    // TODO Q. should we modify Option<String>
     if attrs.is_empty() {
-        return Some((0, None));
+        return Ok((0, None));
     }
     // Rewrite doc comments
     let sugared_docs = take_while_with_pred(context, attrs, |a| a.is_doc_comment());
@@ -230,7 +230,7 @@ fn rewrite_initial_doc_comments(
             .map(|a| context.snippet(a.span))
             .collect::<Vec<_>>()
             .join("\n");
-        return Some((
+        return Ok((
             sugared_docs.len(),
             Some(rewrite_doc_comment(
                 &snippet,
@@ -240,7 +240,7 @@ fn rewrite_initial_doc_comments(
         ));
     }
 
-    Some((0, None))
+    Ok((0, None))
 }
 
 impl Rewrite for ast::NestedMetaItem {
@@ -330,6 +330,10 @@ impl Rewrite for ast::MetaItem {
 
 impl Rewrite for ast::Attribute {
     fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
+        self.rewrite_result(context, shape).ok()
+    }
+
+    fn rewrite_result(&self, context: &RewriteContext<'_>, shape: Shape) -> RewriteResult {
         let snippet = context.snippet(self.span);
         if self.is_doc_comment() {
             rewrite_doc_comment(snippet, shape.comment(context.config), context.config)
@@ -341,7 +345,7 @@ impl Rewrite for ast::Attribute {
             let prefix = attr_prefix(self);
 
             if should_skip || contains_comment(snippet) {
-                return Some(snippet.to_owned());
+                return Ok(snippet.to_owned());
             }
 
             if let Some(ref meta) = self.meta() {
@@ -366,9 +370,11 @@ impl Rewrite for ast::Attribute {
                 }
 
                 // 1 = `[`
-                let shape = shape.offset_left(prefix.len() + 1)?;
-                Some(meta.rewrite(context, shape).map_or_else(
-                    || snippet.to_owned(),
+                let shape = shape
+                    .offset_left(prefix.len() + 1)
+                    .max_width_error(shape.width, self.span)?;
+                Ok(meta.rewrite_result(context, shape).map_or_else(
+                    |_| snippet.to_owned(),
                     |rw| match &self.kind {
                         ast::AttrKind::Normal(normal_attr) => match normal_attr.item.unsafety {
                             // For #![feature(unsafe_attributes)]
@@ -380,16 +386,20 @@ impl Rewrite for ast::Attribute {
                     },
                 ))
             } else {
-                Some(snippet.to_owned())
+                Ok(snippet.to_owned())
             }
         }
     }
 }
 
 impl Rewrite for [ast::Attribute] {
     fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
+        self.rewrite_result(context, shape).ok()
+    }
+
+    fn rewrite_result(&self, context: &RewriteContext<'_>, shape: Shape) -> RewriteResult {
         if self.is_empty() {
-            return Some(String::new());
+            return Ok(String::new());
         }
 
         // The current remaining attributes.
@@ -405,7 +415,7 @@ impl Rewrite for [ast::Attribute] {
         // merging derives into a single attribute.
         loop {
             if attrs.is_empty() {
-                return Some(result);
+                return Ok(result);
             }
 
             // Handle doc comments.
@@ -444,7 +454,7 @@ impl Rewrite for [ast::Attribute] {
             // Handle derives if we will merge them.
             if !skip_derives && context.config.merge_derives() && is_derive(&attrs[0]) {
                 let derives = take_while_with_pred(context, attrs, is_derive);
-                let derive_str = format_derive(derives, shape, context)?;
+                let derive_str = format_derive(derives, shape, context).unknown_error()?;
                 result.push_str(&derive_str);
 
                 let missing_span = attrs
@@ -477,7 +487,7 @@ impl Rewrite for [ast::Attribute] {
             // If we get here, then we have a regular attribute, just handle one
             // at a time.
 
-            let formatted_attr = attrs[0].rewrite(context, shape)?;
+            let formatted_attr = attrs[0].rewrite_result(context, shape)?;
             result.push_str(&formatted_attr);
 
             let missing_span = attrs

src/chains.rs

@@ -267,6 +267,7 @@ impl ChainItemKind {
 }
 
 impl Rewrite for ChainItem {
+    // TODO impl rewrite_result after rebase
     fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
         let shape = shape.sub_width(self.tries)?;
         let rewrite = match self.kind {
@@ -293,7 +294,7 @@ impl Rewrite for ChainItem {
             ),
             ChainItemKind::Await => ".await".to_owned(),
             ChainItemKind::Comment(ref comment, _) => {
-                rewrite_comment(comment, false, shape, context.config)?
+                rewrite_comment(comment, false, shape, context.config).ok()?
             }
         };
         Some(format!("{rewrite}{}", "?".repeat(self.tries)))

src/comment.rs

@@ -6,7 +6,7 @@ use itertools::{multipeek, MultiPeek};
 use rustc_span::Span;
 
 use crate::config::Config;
-use crate::rewrite::RewriteContext;
+use crate::rewrite::{RewriteContext, RewriteErrorExt, RewriteResult};
 use crate::shape::{Indent, Shape};
 use crate::string::{rewrite_string, StringFormat};
 use crate::utils::{
@@ -157,7 +157,7 @@ pub(crate) fn combine_strs_with_missing_comments(
     span: Span,
     shape: Shape,
     allow_extend: bool,
-) -> Option<String> {
+) -> RewriteResult {
     trace!(
         "combine_strs_with_missing_comments `{}` `{}` {:?} {:?}",
         prev_str, next_str, span, shape
@@ -187,7 +187,7 @@ pub(crate) fn combine_strs_with_missing_comments(
             result.push_str(&indent.to_string_with_newline(config))
         }
         result.push_str(next_str);
-        return Some(result);
+        return Ok(result);
     }
 
     // We have a missing comment between the first expression and the second expression.
@@ -232,10 +232,10 @@ pub(crate) fn combine_strs_with_missing_comments(
     result.push_str(&second_sep);
     result.push_str(next_str);
 
-    Some(result)
+    Ok(result)
 }
 
-pub(crate) fn rewrite_doc_comment(orig: &str, shape: Shape, config: &Config) -> Option<String> {
+pub(crate) fn rewrite_doc_comment(orig: &str, shape: Shape, config: &Config) -> RewriteResult {
     identify_comment(orig, false, shape, config, true)
 }
 
@@ -244,7 +244,7 @@ pub(crate) fn rewrite_comment(
     block_style: bool,
     shape: Shape,
     config: &Config,
-) -> Option<String> {
+) -> RewriteResult {
     identify_comment(orig, block_style, shape, config, false)
 }
 
@@ -254,7 +254,7 @@ fn identify_comment(
     shape: Shape,
     config: &Config,
     is_doc_comment: bool,
-) -> Option<String> {
+) -> RewriteResult {
     let style = comment_style(orig, false);
 
     // Computes the byte length of line taking into account a newline if the line is part of a
@@ -346,7 +346,7 @@ fn identify_comment(
     let (first_group, rest) = orig.split_at(first_group_ending);
     let rewritten_first_group =
         if !config.normalize_comments() && has_bare_lines && style.is_block_comment() {
-            trim_left_preserve_layout(first_group, shape.indent, config)?
+            trim_left_preserve_layout(first_group, shape.indent, config).unknown_error()? // TODO
         } else if !config.normalize_comments()
             && !config.wrap_comments()
             && !(
@@ -367,7 +367,7 @@ fn identify_comment(
             )?
         };
     if rest.is_empty() {
-        Some(rewritten_first_group)
+        Ok(rewritten_first_group)
     } else {
         identify_comment(
             rest.trim_start(),
@@ -899,7 +899,7 @@ fn rewrite_comment_inner(
     shape: Shape,
     config: &Config,
     is_doc_comment: bool,
-) -> Option<String> {
+) -> RewriteResult {
     let mut rewriter = CommentRewrite::new(orig, block_style, shape, config);
 
     let line_breaks = count_newlines(orig.trim_end());
@@ -933,7 +933,7 @@ fn rewrite_comment_inner(
         }
     }
 
-    Some(rewriter.finish())
+    Ok(rewriter.finish())
 }
 
 const RUSTFMT_CUSTOM_COMMENT_PREFIX: &str = "//#### ";
@@ -998,15 +998,15 @@ pub(crate) fn rewrite_missing_comment(
     span: Span,
     shape: Shape,
     context: &RewriteContext<'_>,
-) -> Option<String> {
+) -> RewriteResult {
     let missing_snippet = context.snippet(span);
     let trimmed_snippet = missing_snippet.trim();
     // check the span starts with a comment
     let pos = trimmed_snippet.find('/');
     if !trimmed_snippet.is_empty() && pos.is_some() {
         rewrite_comment(trimmed_snippet, false, shape, context.config)
     } else {
-        Some(String::new())
+        Ok(String::new())
     }
 }
 
@@ -1018,13 +1018,13 @@ pub(crate) fn recover_missing_comment_in_span(
     shape: Shape,
     context: &RewriteContext<'_>,
     used_width: usize,
-) -> Option<String> {
+) -> RewriteResult {
     let missing_comment = rewrite_missing_comment(span, shape, context)?;
     if missing_comment.is_empty() {
-        Some(String::new())
+        Ok(String::new())
     } else {
         let missing_snippet = context.snippet(span);
-        let pos = missing_snippet.find('/')?;
+        let pos = missing_snippet.find('/').unknown_error()?;
         // 1 = ` `
         let total_width = missing_comment.len() + used_width + 1;
         let force_new_line_before_comment =
@@ -1034,7 +1034,7 @@ pub(crate) fn recover_missing_comment_in_span(
         } else {
             Cow::from(" ")
         };
-        Some(format!("{sep}{missing_comment}"))
+        Ok(format!("{sep}{missing_comment}"))
     }
 }