deno/cli/diff.rs
2022-07-10 22:49:18 -04:00

228 lines
5.3 KiB
Rust

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use crate::colors;
use dissimilar::{diff as difference, Chunk};
use std::fmt::Write as _;
/// 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) -> String {
if orig_text == edit_text {
return String::new();
}
// normalize newlines as it adds too much noise if they differ
let orig_text = orig_text.replace("\r\n", "\n");
let edit_text = edit_text.replace("\r\n", "\n");
if orig_text == edit_text {
return " | Text differed by line endings.\n".to_string();
}
DiffBuilder::build(&orig_text, &edit_text)
}
struct DiffBuilder {
output: String,
line_number_width: usize,
orig_line: usize,
edit_line: usize,
orig: String,
edit: String,
has_changes: bool,
}
impl DiffBuilder {
pub fn build(orig_text: &str, edit_text: &str) -> String {
let mut diff_builder = DiffBuilder {
output: String::new(),
orig_line: 1,
edit_line: 1,
orig: String::new(),
edit: String::new(),
has_changes: false,
line_number_width: {
let line_count = std::cmp::max(
orig_text.split('\n').count(),
edit_text.split('\n').count(),
);
line_count.to_string().chars().count()
},
};
let chunks = difference(orig_text, edit_text);
diff_builder.handle_chunks(chunks);
diff_builder.output
}
fn handle_chunks<'a>(&'a mut self, chunks: Vec<Chunk<'a>>) {
for chunk in chunks {
match chunk {
Chunk::Delete(s) => {
let split = s.split('\n').enumerate();
for (i, s) in split {
if i > 0 {
self.orig.push('\n');
}
self.orig.push_str(&fmt_rem_text_highlight(s));
}
self.has_changes = true
}
Chunk::Insert(s) => {
let split = s.split('\n').enumerate();
for (i, s) in split {
if i > 0 {
self.edit.push('\n');
}
self.edit.push_str(&fmt_add_text_highlight(s));
}
self.has_changes = true
}
Chunk::Equal(s) => {
let split = s.split('\n').enumerate();
for (i, s) in split {
if i > 0 {
self.flush_changes();
}
self.orig.push_str(&fmt_rem_text(s));
self.edit.push_str(&fmt_add_text(s));
}
}
}
}
self.flush_changes();
}
fn flush_changes(&mut self) {
if self.has_changes {
self.write_line_diff();
self.orig_line += self.orig.split('\n').count();
self.edit_line += self.edit.split('\n').count();
self.has_changes = false;
} else {
self.orig_line += 1;
self.edit_line += 1;
}
self.orig.clear();
self.edit.clear();
}
fn write_line_diff(&mut self) {
let split = self.orig.split('\n').enumerate();
for (i, s) in split {
write!(
self.output,
"{:width$}{} ",
self.orig_line + i,
colors::gray(" |"),
width = self.line_number_width
)
.unwrap();
self.output.push_str(&fmt_rem());
self.output.push_str(s);
self.output.push('\n');
}
let split = self.edit.split('\n').enumerate();
for (i, s) in split {
write!(
self.output,
"{:width$}{} ",
self.edit_line + i,
colors::gray(" |"),
width = self.line_number_width
)
.unwrap();
self.output.push_str(&fmt_add());
self.output.push_str(s);
self.output.push('\n');
}
}
}
fn fmt_add() -> String {
colors::green_bold("+").to_string()
}
fn fmt_add_text(x: &str) -> String {
colors::green(x).to_string()
}
fn fmt_add_text_highlight(x: &str) -> String {
colors::black_on_green(x).to_string()
}
fn fmt_rem() -> String {
colors::red_bold("-").to_string()
}
fn fmt_rem_text(x: &str) -> String {
colors::red(x).to_string()
}
fn fmt_rem_text_highlight(x: &str) -> String {
colors::white_on_red(x).to_string()
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_diff() {
run_test(
"console.log('Hello World')",
"console.log(\"Hello World\");",
concat!(
"1 | -console.log('Hello World')\n",
"1 | +console.log(\"Hello World\");\n",
),
);
run_test(
"\n\n\n\nconsole.log(\n'Hello World'\n)",
"console.log(\n\"Hello World\"\n);",
concat!(
"1 | -\n",
"2 | -\n",
"3 | -\n",
"4 | -\n",
"5 | -console.log(\n",
"1 | +console.log(\n",
"6 | -'Hello World'\n",
"2 | +\"Hello World\"\n",
"7 | -)\n3 | +);\n",
),
);
}
#[test]
fn test_eof_newline_missing() {
run_test(
"test\nsome line text test",
"test\nsome line text test\n",
concat!(
"2 | -some line text test\n",
"2 | +some line text test\n",
"3 | +\n",
),
);
}
#[test]
fn test_newlines_differing() {
run_test("test\n", "test\r\n", " | Text differed by line endings.\n");
}
fn run_test(diff_text1: &str, diff_text2: &str, expected_output: &str) {
assert_eq!(
test_util::strip_ansi_codes(&diff(diff_text1, diff_text2,)),
expected_output,
);
}
}