Remove coverage mode (#4015)

Author: topecongiro

README.md

@@ -218,7 +218,6 @@ needs to be specified in `rustfmt.toml`, e.g., with `edition = "2018"`.
   | :--------: | :-----------------------------------------------: | :----------: |
   |   files    |            overwrites output to files             |      No      |
   |   stdout   |              writes output to stdout              |      No      |
-  |  coverage  | displays how much of the input file was processed |     Yes      |
   | checkstyle |           emits in a checkstyle format            |     Yes      |
   |    json    |           emits diffs in a json format            |     Yes      |
 

rustfmt-core/rustfmt-lib/src/config/options.rs

@@ -115,8 +115,6 @@ pub enum EmitMode {
     Files,
     /// Writes the output to stdout.
     Stdout,
-    /// Displays how much of the input file was processed
-    Coverage,
     /// Unfancy stdout
     Checkstyle,
     /// Writes the resulting diffs in a JSON format. Returns an empty array

rustfmt-core/rustfmt-lib/src/coverage.rs

@@ -46,7 +46,6 @@ mod attr;
 mod chains;
 mod closures;
 mod comment;
-mod coverage;
 mod expr;
 mod format_report_formatter;
 pub(crate) mod formatting;
@@ -473,9 +472,7 @@ pub(crate) fn create_emitter<'a>(config: &Config) -> Box<dyn Emitter + 'a> {
         EmitMode::Files => Box::new(emitter::FilesEmitter::new(
             config.print_misformatted_file_names(),
         )),
-        EmitMode::Stdout | EmitMode::Coverage => {
-            Box::new(emitter::StdoutEmitter::new(config.verbose()))
-        }
+        EmitMode::Stdout => Box::new(emitter::StdoutEmitter::new(config.verbose())),
         EmitMode::Json => Box::new(emitter::JsonEmitter::default()),
         EmitMode::ModifiedLines => Box::new(emitter::ModifiedLinesEmitter::default()),
         EmitMode::Checkstyle => Box::new(emitter::CheckstyleEmitter::default()),

rustfmt-core/rustfmt-lib/src/lib.rs

@@ -3,7 +3,6 @@ use rustc_span::{BytePos, Pos, Span};
 use crate::comment::{is_last_comment_block, rewrite_comment, CodeCharKind, CommentCodeSlices};
 use crate::config::file_lines::FileLines;
 use crate::config::FileName;
-use crate::coverage::transform_missing_snippet;
 use crate::shape::{Indent, Shape};
 use crate::source_map::LineRangeUtils;
 use crate::utils::{
@@ -155,7 +154,7 @@ impl<'a> FmtVisitor<'a> {
     fn write_snippet_inner<F>(
         &mut self,
         big_snippet: &str,
-        old_snippet: &str,
+        snippet: &str,
         big_diff: usize,
         span: Span,
         process_last_snippet: F,
@@ -169,8 +168,6 @@ impl<'a> FmtVisitor<'a> {
         let file_name = &self.parse_sess.span_to_filename(span);
         let mut status = SnippetStatus::new(line);
 
-        let snippet = &*transform_missing_snippet(self.config, old_snippet);
-
         let slice_within_file_lines_range =
             |file_lines: FileLines, cur_line, s| -> (usize, usize, bool) {
                 let (lf_count, crlf_count) = count_lf_crlf(s);

rustfmt-core/rustfmt-lib/src/missed_spans.rs

@@ -193,22 +193,6 @@ fn system_tests() {
     });
 }
 
-// Do the same for tests/coverage-source directory.
-// The only difference is the coverage mode.
-#[test]
-fn coverage_tests() {
-    init_log();
-    let files = get_test_files(
-        Path::new("tests/coverage/source"),
-        true,
-        SKIP_FILE_WHITE_LIST,
-    );
-    let (_reports, count, fails) = check_files(files, &None);
-
-    println!("Ran {} tests in coverage mode.", count);
-    assert_eq!(fails, 0, "{} tests failed", fails);
-}
-
 #[test]
 fn checkstyle_test() {
     init_log();

rustfmt-core/rustfmt-lib/src/test/mod.rs

@@ -7,7 +7,6 @@ use rustc_span::{BytePos, Pos, Span};
 use crate::attr::*;
 use crate::comment::{rewrite_comment, CodeCharKind, CommentCodeSlices};
 use crate::config::{BraceStyle, Config};
-use crate::coverage::transform_missing_snippet;
 use crate::items::{
     format_impl, format_trait, format_trait_alias, is_mod_decl, is_use_item,
     rewrite_associated_impl_type, rewrite_associated_type, rewrite_extern_crate,
@@ -268,7 +267,6 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
         )
         .peekable();
         while let Some((kind, offset, sub_slice)) = iter.next() {
-            let sub_slice = transform_missing_snippet(config, sub_slice);
             debug!("close_block: {:?} {:?} {:?}", kind, offset, sub_slice);
 
             match kind {