dprint 0.21.2

Binary for dprint code formatter—a pluggable and configurable code formatting platform.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203

use std::time::Duration;

use crossterm::style::Stylize;
use similar::ChangeTag;
use similar::TextDiffConfig;

/// Gets a string showing the difference between two strings.
pub fn get_difference(old_text: &str, new_text: &str) -> String {
  debug_assert!(old_text != new_text);

  // normalize newlines
  let old_text = old_text.replace("\r\n", "\n");
  let new_text = new_text.replace("\r\n", "\n");

  if old_text == new_text {
    return String::from(" | Text differed by line endings.");
  }

  let mut config = TextDiffConfig::default();
  config.timeout(Duration::from_millis(500));

  let diff = config.diff_lines(&old_text, &new_text);

  let mut output = String::new();
  for hunk in diff.unified_diff().iter_hunks() {
    if !output.is_empty() {
      output.push_str("\n...");
    }
    let max_old_line_num_width = get_number_char_count(hunk.iter_changes().filter_map(|c| c.old_index().map(|i| i + 1)));
    let max_new_line_num_width = get_number_char_count(hunk.iter_changes().filter_map(|c| c.new_index().map(|i| i + 1)));
    for op in hunk.ops() {
      for change in diff.iter_inline_changes(op) {
        if !output.is_empty() {
          output.push('\n');
        }
        let sign = match change.tag() {
          ChangeTag::Delete => get_removal_text("-"),
          ChangeTag::Insert => get_addition_text("+"),
          ChangeTag::Equal => " ".to_string(),
        };
        output.push_str(&format!(
          "{:>old_width$} {:>new_width$}|{}",
          change.new_index().map(|i| (i + 1).to_string()).unwrap_or_else(|| "".to_string()),
          change.old_index().map(|i| (i + 1).to_string()).unwrap_or_else(|| "".to_string()),
          sign,
          old_width = max_old_line_num_width,
          new_width = max_new_line_num_width,
        ));
        for (highlight, change_text) in change.iter_strings_lossy() {
          let change_text = if let Some(change_text) = change_text.strip_suffix("\r\n") {
            change_text
          } else if let Some(change_text) = change_text.strip_suffix('\n') {
            change_text
          } else {
            &change_text
          };
          let change_text = annotate_whitespace(change_text);
          if !change_text.is_empty() {
            let change_text = if highlight {
              match change.tag() {
                ChangeTag::Delete => get_removal_highlight_text(&change_text),
                ChangeTag::Insert => get_addition_highlight_text(&change_text),
                ChangeTag::Equal => change_text,
              }
            } else {
              get_text_for_tag(change.tag(), change_text)
            };
            output.push_str(&change_text);
          }
        }
        if change.missing_newline() {
          // show a ETX (end of text)
          output.push_str(&get_text_for_tag(change.tag(), "\u{2403}".to_string()));
        }
      }
    }
  }

  output
}

fn get_text_for_tag(tag: ChangeTag, text: String) -> String {
  match tag {
    ChangeTag::Delete => get_removal_text(&text),
    ChangeTag::Insert => get_addition_text(&text),
    ChangeTag::Equal => text,
  }
}

fn get_number_char_count(numbers: impl Iterator<Item = usize>) -> usize {
  numbers.max().unwrap_or(1).to_string().chars().count()
}

fn get_addition_text(text: &str) -> String {
  text.green().to_string()
}

fn get_addition_highlight_text(text: &str) -> String {
  let text = text.replace("\t", "\u{21E5}");
  text.white().on_green().to_string()
}

fn get_removal_text(text: &str) -> String {
  let text = text.replace("\t", "\u{21E5}");
  text.red().to_string()
}

fn get_removal_highlight_text(text: &str) -> String {
  let text = text.replace("\t", "\u{21E5}");
  text.white().on_red().to_string()
}

fn annotate_whitespace(text: &str) -> String {
  text.replace("\t", "\u{2192}").replace(" ", "\u{00B7}")
}

#[cfg(test)]
mod test {
  use super::*;
  use pretty_assertions::assert_eq;

  #[test]
  fn should_get_when_differs_by_line_endings() {
    assert_eq!(get_difference("test\r\n", "test\n"), " | Text differed by line endings.");
  }

  #[test]
  fn should_get_difference_on_one_line() {
    assert_eq!(
      get_difference("test1\n", "test2\n"),
      format!(
        "  1|{}{}\n1  |{}{}",
        get_removal_text("-"),
        get_removal_highlight_text("test1"),
        get_addition_text("+"),
        get_addition_highlight_text("test2"),
      )
    );
  }

  #[test]
  fn should_show_the_addition_of_last_line() {
    assert_eq!(
      get_difference("testing\ntesting", "testing\ntesting\n"),
      format!(
        "1 1| testing\n  2|{}{}{}\n2  |{}{}",
        get_removal_text("-"),
        get_removal_text("testing"),
        get_removal_text("\u{2403}"), // end of text
        get_addition_text("+"),
        get_addition_text("testing"),
      )
    );
  }

  #[test]
  fn should_get_difference_for_removed_line() {
    assert_eq!(
      get_difference("class Test\n{\n\n}", "class Test {\n}\n"),
      format!(
        "{}\n{}\n{}\n{}\n{}\n{}",
        format!("  1|{}{}", get_removal_text("-"), get_removal_text(&annotate_whitespace("class Test")),),
        format!("  2|{}{}", get_removal_text("-"), get_removal_text("{"),),
        format!("  3|{}", get_removal_text("-")),
        format!(
          "  4|{}{}{}",
          get_removal_text("-"),
          get_removal_text("}"),
          get_removal_text("\u{2403}"), // end of text
        ),
        format!(
          "1  |{}{}{}{}",
          get_addition_text("+"),
          get_addition_text(&annotate_whitespace("class Test")),
          get_addition_highlight_text(&annotate_whitespace(" ")),
          get_addition_text("{"),
        ),
        format!("2  |{}{}", get_addition_text("+"), get_addition_text("}"),),
      )
    );
  }

  #[test]
  fn should_show_multiple_removals_on_different_lines() {
    assert_eq!(
      get_difference("test ;\n1\n2\n3\n4\n5\n6\n7\n8\n9\ntest ;\n", "test;\n1\n2\n3\n4\n5\n6\n7\n8\n9\ntest;\n"),
      format!(
        "{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}",
        format!("  1|{}{}", get_removal_text("-"), get_removal_text(&annotate_whitespace("test ;")),),
        format!("1  |{}{}", get_addition_text("+"), get_addition_text("test;"),),
        "2 2| 1",
        "3 3| 2",
        "4 4| 3",
        "...",
        " 8  8| 7",
        " 9  9| 8",
        "10 10| 9",
        format!("   11|{}{}", get_removal_text("-"), get_removal_text(&annotate_whitespace("test ;")),),
        format!("11   |{}{}", get_addition_text("+"), get_addition_text("test;"),),
      )
    );
  }
}