Switch to replace-rs

Author: killercup

Cargo.toml

@@ -20,6 +20,8 @@ exclude = [
 serde = "1.0"
 serde_json = "1.0"
 serde_derive = "1.0"
+replace-rs = { git = "https://github.com/killercup/replace-rs" }
+failure = "0.1.1"
 
 [dev-dependencies]
 duct = "0.8.2"

cargo-fix/src/main.rs

@@ -171,7 +171,7 @@ fn rustfix_crate(rustc: &Path, filename: &str) -> Result<(), Error> {
             warn!("failed to read `{}`: {}", file, e);
             continue
         }
-        let new_code = rustfix::apply_suggestions(&code, &suggestions);
+        let new_code = rustfix::apply_suggestions(&code, &suggestions)?;
         File::create(&file)
             .and_then(|mut f| f.write_all(new_code.as_bytes()))
             .with_context(|_| format!("failed to write file `{}`", file))?;

src/diagnostics.rs

@@ -1,5 +1,5 @@
 //! Rustc Diagnostic JSON Output
-//! 
+//!
 //! The following data types are copied from [rust-lang/rust](https://github.com/rust-lang/rust/blob/de78655bca47cac8e783dbb563e7e5c25c1fae40/src/libsyntax/json.rs)
 
 #[derive(Deserialize, Debug)]
@@ -21,8 +21,8 @@ pub struct Diagnostic {
 #[derive(Deserialize, Debug)]
 pub struct DiagnosticSpan {
     pub file_name: String,
-    byte_start: u32,
-    byte_end: u32,
+    pub byte_start: u32,
+    pub byte_end: u32,
     /// 1-based.
     pub line_start: usize,
     pub line_end: usize,

src/lib.rs

@@ -1,8 +1,13 @@
 #[macro_use]
 extern crate serde_derive;
 extern crate serde_json;
+extern crate failure;
+extern crate replace_rs as replace;
 
 use std::collections::HashSet;
+use std::ops::Range;
+
+use failure::Error;
 
 pub mod diagnostics;
 use diagnostics::{Diagnostic, DiagnosticSpan};
@@ -61,6 +66,7 @@ pub struct Solution {
 pub struct Snippet {
     pub file_name: String,
     pub line_range: LineRange,
+    pub range: Range<usize>,
     /// leading surrounding text, text to replace, trailing surrounding text
     ///
     /// This split is useful for higlighting the part that gets replaced
@@ -109,6 +115,7 @@ fn parse_snippet(span: &DiagnosticSpan) -> Snippet {
                 column: span.column_end,
             },
         },
+        range: (span.byte_start as usize)..(span.byte_end as usize),
         text: (lead, body, tail),
     }
 }
@@ -208,16 +215,22 @@ pub fn apply_suggestion(file_content: &mut String, suggestion: &Replacement) ->
     new_content
 }
 
-pub fn apply_suggestions(code: &str, suggestions: &[Suggestion]) -> String {
-    let mut fixed = code.to_string();
+pub fn apply_suggestions(code: &str, suggestions: &[Suggestion]) -> Result<String, Error> {
+    use replace::Data;
+
+    let mut fixed = Data::new(code.as_bytes());
 
     for sug in suggestions.iter().rev() {
         for sol in &sug.solutions {
             for r in &sol.replacements {
-                fixed = apply_suggestion(&mut fixed, r);
+                fixed.replace_range(
+                    r.snippet.range.start,
+                    r.snippet.range.end - 1,
+                    r.replacement.as_bytes(),
+                )?;
             }
         }
     }
 
-    fixed
+    Ok(String::from_utf8(fixed.to_vec())?)
 }

tests/everything.rs

@@ -15,14 +15,15 @@ use std::collections::HashSet;
 use std::process::Output;
 use tempdir::TempDir;
 
-use rustfix::{Replacement, apply_suggestions};
+use rustfix::apply_suggestions;
 
 fn compile(file: &Path) -> Result<Output, Box<Error>> {
     let tmp = TempDir::new("rustfix-tests")?;
     let better_call_clippy = cmd!(
         "rustc", file,
         "--error-format=pretty-json", "-Zunstable-options", "--emit=metadata",
         "--crate-name=rustfix_test",
+        "-Zsuggestion-applicability",
         "--out-dir", tmp.path()
     );
     let res = better_call_clippy
@@ -101,7 +102,7 @@ fn test_rustfix_with_file<P: AsRef<Path>>(file: P) -> Result<(), Box<Error>> {
         "got unexpected suggestions from clippy",
     );
 
-    let fixed = apply_suggestions(&code, &suggestions);
+    let fixed = apply_suggestions(&code, &suggestions)?;
 
     if std::env::var("RUSTFIX_TEST_RECORD_FIXED_RUST").is_ok() {
         use std::io::Write;
@@ -110,7 +111,7 @@ fn test_rustfix_with_file<P: AsRef<Path>>(file: P) -> Result<(), Box<Error>> {
     }
 
     let expected_fixed = read_file(&fixed_file)?;
-    assert_eq!(fixed.trim(), expected_fixed.trim(), "file doesn't look fixed");
+    assert_eq!(fixed.trim(), expected_fixed.trim(), "file {} doesn't look fixed", file.display());
 
     compiles_without_errors(&fixed_file)?;