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denoland-deno/cli/diff.rs

171 lines
4.2 KiB
Rust

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
use crate::colors;
use dissimilar::{diff as difference, Chunk};
use std::fmt;
use std::fmt::Write;
fn fmt_add() -> String {
format!("{}", colors::green_bold("+"))
}
fn fmt_add_text(x: &str) -> String {
format!("{}", colors::green(x))
}
fn fmt_add_text_highlight(x: &str) -> String {
format!("{}", colors::white_on_green(x))
}
fn fmt_rem() -> String {
format!("{}", colors::red_bold("-"))
}
fn fmt_rem_text(x: &str) -> String {
format!("{}", colors::red(x))
}
fn fmt_rem_text_highlight(x: &str) -> String {
format!("{}", colors::white_on_red(x))
}
fn write_line_diff(
diff: &mut String,
orig_line: &mut usize,
edit_line: &mut usize,
line_number_width: usize,
orig: &mut String,
edit: &mut String,
) -> fmt::Result {
let split = orig.split('\n').enumerate();
for (i, s) in split {
write!(
diff,
"{:0width$}{} ",
*orig_line + i,
colors::gray("|"),
width = line_number_width
)?;
write!(diff, "{}", fmt_rem())?;
write!(diff, "{}", s)?;
writeln!(diff)?;
}
let split = edit.split('\n').enumerate();
for (i, s) in split {
write!(
diff,
"{:0width$}{} ",
*edit_line + i,
colors::gray("|"),
width = line_number_width
)?;
write!(diff, "{}", fmt_add())?;
write!(diff, "{}", s)?;
writeln!(diff)?;
}
*orig_line += orig.split('\n').count();
*edit_line += edit.split('\n').count();
orig.clear();
edit.clear();
Ok(())
}
/// Print diff of the same file_path, before and after formatting.
///
/// Diff format is loosely based on Github diff formatting.
pub fn diff(orig_text: &str, edit_text: &str) -> Result<String, fmt::Error> {
let lines = edit_text.split('\n').count();
let line_number_width = lines.to_string().chars().count();
let mut diff = String::new();
let mut text1 = orig_text.to_string();
let mut text2 = edit_text.to_string();
if !text1.ends_with('\n') {
writeln!(text1)?;
}
if !text2.ends_with('\n') {
writeln!(text2)?;
}
let mut orig_line: usize = 1;
let mut edit_line: usize = 1;
let mut orig: String = String::new();
let mut edit: String = String::new();
let mut changes = false;
let chunks = difference(&text1, &text2);
for chunk in chunks {
match chunk {
Chunk::Delete(s) => {
let split = s.split('\n').enumerate();
for (i, s) in split {
if i > 0 {
orig.push_str("\n");
}
orig.push_str(&fmt_rem_text_highlight(s));
}
changes = true
}
Chunk::Insert(s) => {
let split = s.split('\n').enumerate();
for (i, s) in split {
if i > 0 {
edit.push_str("\n");
}
edit.push_str(&fmt_add_text_highlight(s));
}
changes = true
}
Chunk::Equal(s) => {
let split = s.split('\n').enumerate();
for (i, s) in split {
if i > 0 {
if changes {
write_line_diff(
&mut diff,
&mut orig_line,
&mut edit_line,
line_number_width,
&mut orig,
&mut edit,
)?;
changes = false
} else {
orig.clear();
edit.clear();
orig_line += 1;
edit_line += 1;
}
}
orig.push_str(&fmt_rem_text(s));
edit.push_str(&fmt_add_text(s));
}
}
}
}
Ok(diff)
}
#[test]
fn test_diff() {
let simple_console_log_unfmt = "console.log('Hello World')";
let simple_console_log_fmt = "console.log(\"Hello World\");";
assert_eq!(
colors::strip_ansi_codes(
&diff(simple_console_log_unfmt, simple_console_log_fmt).unwrap()
),
"1| -console.log('Hello World')\n1| +console.log(\"Hello World\");\n"
);
let line_number_unfmt = "\n\n\n\nconsole.log(\n'Hello World'\n)";
let line_number_fmt = "console.log(\n\"Hello World\"\n);";
assert_eq!(
colors::strip_ansi_codes(&diff(line_number_unfmt, line_number_fmt).unwrap()),
"1| -\n2| -\n3| -\n4| -\n5| -console.log(\n1| +console.log(\n6| -'Hello World'\n2| +\"Hello World\"\n7| -)\n3| +);\n"
)
}