Create the side-by-side option (-y) feature for the diff command (Incomplete)

.github/workflows/fuzzing.yml

@@ -46,6 +46,7 @@ jobs:
           - { name: fuzz_ed, should_pass: true }
           - { name: fuzz_normal, should_pass: true }
           - { name: fuzz_patch, should_pass: true }
+          - { name: fuzz_side, should_pass: true }
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@nightly

fuzz/Cargo.toml

@@ -47,4 +47,8 @@ path = "fuzz_targets/fuzz_ed.rs"
 test = false
 doc = false
 
-
+[[bin]]
+name = "fuzz_side"
+path = "fuzz_targets/fuzz_side.rs"
+test = false
+doc = false

fuzz/fuzz_targets/fuzz_side.rs

@@ -0,0 +1,42 @@
+#![no_main]
+#[macro_use]
+extern crate libfuzzer_sys;
+
+use diffutilslib::side_diff;
+
+use std::fs::File;
+use std::io::Write;
+use diffutilslib::params::Params;
+
+fuzz_target!(|x: (Vec<u8>, Vec<u8>, /* usize, usize */ bool)| {
+    let (original, new, /* width, tabsize, */ expand) = x;
+
+    // if width == 0 || tabsize == 0 {
+    //     return;
+    // }
+
+    let params = Params {
+        // width,
+        // tabsize,
+        expand_tabs: expand,
+        ..Default::default()
+    };
+    let mut output_buf = vec![];
+    side_diff::diff(&original, &new, &mut output_buf, &params);
+    File::create("target/fuzz.file.original")
+        .unwrap()
+        .write_all(&original)
+        .unwrap();
+    File::create("target/fuzz.file.new")
+        .unwrap()
+        .write_all(&new)
+        .unwrap();
+    File::create("target/fuzz.file")
+        .unwrap()
+        .write_all(&original)
+        .unwrap();
+    File::create("target/fuzz.diff")
+        .unwrap()
+        .write_all(&output_buf)
+        .unwrap();
+});

src/diff.rs

@@ -5,11 +5,11 @@
 
 use crate::params::{parse_params, Format};
 use crate::utils::report_failure_to_read_input_file;
-use crate::{context_diff, ed_diff, normal_diff, unified_diff};
+use crate::{context_diff, ed_diff, normal_diff, side_diff, unified_diff};
 use std::env::ArgsOs;
 use std::ffi::OsString;
 use std::fs;
-use std::io::{self, Read, Write};
+use std::io::{self, stdout, Read, Write};
 use std::iter::Peekable;
 use std::process::{exit, ExitCode};
 
@@ -79,6 +79,10 @@
             eprintln!("{error}");
             exit(2);
         }),
+        Format::SideBySide => {
+            let mut output = stdout().lock();
+            side_diff::diff(&from_content, &to_content, &mut output, &params)
+        }
     };
     if params.brief && !result.is_empty() {
         println!(

src/lib.rs

@@ -4,11 +4,13 @@ pub mod ed_diff;
 pub mod macros;
 pub mod normal_diff;
 pub mod params;
+pub mod side_diff;
 pub mod unified_diff;
 pub mod utils;
 
 // Re-export the public functions/types you need
 pub use context_diff::diff as context_diff;
 pub use ed_diff::diff as ed_diff;
 pub use normal_diff::diff as normal_diff;
+pub use side_diff::diff as side_by_side_diff;
 pub use unified_diff::diff as unified_diff;

src/main.rs

@@ -18,6 +18,7 @@ mod ed_diff;
 mod macros;
 mod normal_diff;
 mod params;
+mod side_diff;
 mod unified_diff;
 mod utils;
 

src/params.rs

@@ -11,6 +11,7 @@
     Unified,
     Context,
     Ed,
+    SideBySide,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
@@ -24,6 +25,7 @@
     pub brief: bool,
     pub expand_tabs: bool,
     pub tabsize: usize,
+    pub width: usize,
 }
 
 impl Default for Params {
@@ -38,6 +40,7 @@
             brief: false,
             expand_tabs: false,
             tabsize: 8,
+            width: 130,
         }
     }
 }
@@ -57,6 +60,7 @@
     let mut format = None;
     let mut context = None;
     let tabsize_re = Regex::new(r"^--tabsize=(?<num>\d+)$").unwrap();
+    let width_re = Regex::new(r"--width=(?P<long>\d+)$").unwrap();
     while let Some(param) = opts.next() {
         let next_param = opts.peek();
         if param == "--" {
@@ -101,6 +105,34 @@
             format = Some(Format::Ed);
             continue;
         }
+        if param == "-y" || param == "--side-by-side" {
+            if format.is_some() && format != Some(Format::SideBySide) {
+                return Err("Conflicting output style option".to_string());
+            }
+            format = Some(Format::SideBySide);
+            continue;
+        }
+        if width_re.is_match(param.to_string_lossy().as_ref()) {
+            let param = param.into_string().unwrap();
+            let width_str: &str = width_re
+                .captures(param.as_str())
+                .unwrap()
+                .name("long")
+                .unwrap()
+                .as_str();
+
+            params.width = match width_str.parse::<usize>() {
+                Ok(num) => {
+                    if num == 0 {
+                        return Err("invalid width «0»".to_string());
+                    }
+
+                    num
+                }
+                Err(_) => return Err(format!("invalid width «{width_str}»")),
+            };
+            continue;
+        }
         if tabsize_re.is_match(param.to_string_lossy().as_ref()) {
             // Because param matches the regular expression,
             // it is safe to assume it is valid UTF-8.
@@ -112,9 +144,16 @@
                 .unwrap()
                 .as_str();
             params.tabsize = match tabsize_str.parse::<usize>() {
-                Ok(num) => num,
+                Ok(num) => {
+                    if num == 0 {
+                        return Err("invalid tabsize «0»".to_string());
+                    }
+
+                    num
+                }
                 Err(_) => return Err(format!("invalid tabsize «{tabsize_str}»")),
             };
+
             continue;
         }
         match match_context_diff_params(&param, next_param, format) {
@@ -704,11 +743,11 @@
                 executable: os("diff"),
                 from: os("foo"),
                 to: os("bar"),
-                tabsize: 0,
+                tabsize: 1,
                 ..Default::default()
             }),
             parse_params(
-                [os("diff"), os("--tabsize=0"), os("foo"), os("bar")]
+                [os("diff"), os("--tabsize=1"), os("foo"), os("bar")]
                     .iter()
                     .cloned()
                     .peekable()