Handle git blame

Cargo.toml

@@ -15,6 +15,8 @@ name = "delta"
 path = "src/main.rs"
 
 [dependencies]
+chrono = "0.4.19"
+chrono-humanize = "0.2.1"
 ansi_colours = "1.0.4"
 ansi_term = "0.12.1"
 atty = "0.2.14"

README.md

@@ -22,6 +22,7 @@
     diff = delta
     show = delta
     log = delta
+    blame = delta
     reflog = delta
 
 [interactive]
@@ -63,11 +64,13 @@ Code evolves, and we all spend time studying diffs. Delta aims to make this both
   - [Choosing colors (styles)](#choosing-colors-styles)
   - [Line numbers](#line-numbers)
   - [Side-by-side view](#side-by-side-view)
+  - [git blame](#git-blame)
   - ["Features": named groups of settings](#features-named-groups-of-settings)
   - [Custom themes](#custom-themes)
   - [diff-highlight and diff-so-fancy emulation](#diff-highlight-and-diff-so-fancy-emulation)
   - [--color-moved support](#--color-moved-support)
   - [Navigation keybindings for large diffs](#navigation-keybindings-for-large-diffs)
+  - [Git blame](#git-blame-1)
   - [24 bit color (truecolor)](#24-bit-color-truecolor)
   - [Using Delta with GNU Screen](#using-delta-with-gnu-screen)
   - [Using Delta on Windows](#using-delta-on-windows)
@@ -152,6 +155,7 @@ Here's what `git show` can look like with git configured to use delta:
 - `diff-highlight` and `diff-so-fancy` emulation modes
 - Stylable box/line decorations to draw attention to commit, file and hunk header sections.
 - Support for Git's `--color-moved` feature.
+- Customizable `git blame` with syntax highlighting (`--hyperlinks` formats commits as links to GitHub/GitLab/Bitbucket etc)
 - Code can be copied directly from the diff (`-/+` markers are removed by default).
 - `n` and `N` keybindings to move between files in large diffs, and between diffs in `log -p` views (`--navigate`)
 - Commit hashes can be formatted as terminal [hyperlinks](https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda) to the GitHub/GitLab/Bitbucket page (`--hyperlinks`).
@@ -407,6 +411,10 @@ In contrast, the long replacement line in the right panel overflows by almost an
 For control over the details of line wrapping, see `--wrap-max-lines`, `--wrap-left-symbol`, `--wrap-right-symbol`, `--wrap-right-percent`, `--wrap-right-prefix-symbol`, `--inline-hint-style`.
 Line wrapping was implemented by @th1000s.
 
+### git blame
+
+Set delta as the pager for `blame` in the `[pager]` section of your gitconfig. See the example at the [top of the page](#get-started).
+
 ### "Features": named groups of settings
 
 All delta options can go under the `[delta]` section in your git config file. However, you can also use named "features" to keep things organized: these are sections in git config like `[delta "my-feature"]`. Here's an example using two custom features:
@@ -493,6 +501,12 @@ In order to support this feature, Delta has to look at the raw colors it receive
 
 Use the `navigate` feature to activate navigation keybindings. In this mode, pressing `n` will jump forward to the next file in the diff, and `N` will jump backwards. If you are viewing multiple commits (e.g. via `git log -p`) then navigation will also visit commit boundaries.
 
+### Git blame
+
+Delta will render `git blame` output in its own way, if you have `pager.blame = delta` set in your `gitconfig`. Example:
+
+<table><tr><td><img width=300px src="https://user-images.githubusercontent.com/52205/140330813-91b198af-c396-4c5e-9a30-26ee35b78e7e.png" alt="image" /></td></tr></table>
+
 ### 24 bit color (truecolor)
 
 Delta looks best if your terminal application supports 24 bit colors. See https://github.com/termstandard/colors#readme. For example, on MacOS, iTerm2 supports 24-bit colors but Terminal.app does not.

src/cli.rs

@@ -420,6 +420,27 @@ pub struct Opt {
     /// (underline), 'ol' (overline), or the combination 'ul ol'.
     pub hunk_header_decoration_style: String,
 
+    /// Format string for git blame commit metadata. Available placeholders are
+    /// "{timestamp}", "{author}", and "{commit}".
+    #[structopt(
+        long = "blame-format",
+        default_value = "{timestamp:<15} {author:<15.14} {commit:<8} │ "
+    )]
+    pub blame_format: String,
+
+    /// Background colors used for git blame lines (space-separated string).
+    /// Lines added by the same commit are painted with the same color; colors
+    /// are recycled as needed.
+    #[structopt(long = "blame-palette")]
+    pub blame_palette: Option<String>,
+
+    /// Format of `git blame` timestamp in raw git output received by delta.
+    #[structopt(
+        long = "blame-timestamp-format",
+        default_value = "%Y-%m-%d %H:%M:%S %z"
+    )]
+    pub blame_timestamp_format: String,
+
     /// Default language used for syntax highlighting when this cannot be
     /// inferred from a filename. It will typically make sense to set this in
     /// per-repository git config (.git/config)

src/color.rs

@@ -162,3 +162,9 @@ const DARK_THEME_PLUS_COLOR_256: Color = Color::Fixed(22);
 const DARK_THEME_PLUS_EMPH_COLOR: Color = Color::RGB(0x00, 0x60, 0x00);
 
 const DARK_THEME_PLUS_EMPH_COLOR_256: Color = Color::Fixed(28);
+
+// blame
+
+pub const LIGHT_THEME_BLAME_PALETTE: &[&str] = &["#FFFFFF", "#DDDDDD", "#BBBBBB"];
+
+pub const DARK_THEME_BLAME_PALETTE: &[&str] = &["#000000", "#222222", "#444444"];

src/config.rs

@@ -57,6 +57,9 @@ fn adapt_wrap_max_lines_argument(arg: String) -> usize {
 pub struct Config {
     pub available_terminal_width: usize,
     pub background_color_extends_to_terminal_width: bool,
+    pub blame_format: String,
+    pub blame_palette: Vec<String>,
+    pub blame_timestamp_format: String,
     pub color_only: bool,
     pub commit_regex: Regex,
     pub commit_style: Style,
@@ -213,6 +216,8 @@ impl From<cli::Opt> for Config {
             _ => *style::GIT_DEFAULT_PLUS_STYLE,
         };
 
+        let blame_palette = make_blame_palette(opt.blame_palette, opt.computed.is_light_mode);
+
         let file_added_label = opt.file_added_label;
         let file_copied_label = opt.file_copied_label;
         let file_modified_label = opt.file_modified_label;
@@ -257,6 +262,9 @@ impl From<cli::Opt> for Config {
             background_color_extends_to_terminal_width: opt
                 .computed
                 .background_color_extends_to_terminal_width,
+            blame_format: opt.blame_format,
+            blame_palette,
+            blame_timestamp_format: opt.blame_timestamp_format,
             commit_style,
             color_only: opt.color_only,
             commit_regex,
@@ -603,6 +611,23 @@ fn make_commit_file_hunk_header_styles(opt: &cli::Opt) -> (Style, Style, Style,
     )
 }
 
+fn make_blame_palette(blame_palette: Option<String>, is_light_mode: bool) -> Vec<String> {
+    match (blame_palette, is_light_mode) {
+        (Some(string), _) => string
+            .split_whitespace()
+            .map(|s| s.to_owned())
+            .collect::<Vec<String>>(),
+        (None, true) => color::LIGHT_THEME_BLAME_PALETTE
+            .iter()
+            .map(|s| s.to_string())
+            .collect::<Vec<String>>(),
+        (None, false) => color::DARK_THEME_BLAME_PALETTE
+            .iter()
+            .map(|s| s.to_string())
+            .collect::<Vec<String>>(),
+    }
+}
+
 /// Did the user supply `option` on the command line?
 pub fn user_supplied_option(option: &str, arg_matches: &clap::ArgMatches) -> bool {
     arg_matches.occurrences_of(option) > 0

src/delta.rs

@@ -1,4 +1,5 @@
 use std::borrow::Cow;
+use std::collections::HashMap;
 use std::io::BufRead;
 use std::io::Write;
 
@@ -13,14 +14,15 @@ use crate::style::DecorationStyle;
 
 #[derive(Clone, Debug, PartialEq)]
 pub enum State {
-    CommitMeta,                 // In commit metadata section
+    CommitMeta,                    // In commit metadata section
     FileMeta, // In diff metadata section, between (possible) commit metadata and first hunk
     HunkHeader(String, String), // In hunk metadata line (line, raw_line)
     HunkZero, // In hunk; unchanged line
     HunkMinus(Option<String>), // In hunk; removed line (raw_line)
     HunkPlus(Option<String>), // In hunk; added line (raw_line)
     SubmoduleLog, // In a submodule section, with gitconfig diff.submodule = log
     SubmoduleShort(String), // In a submodule section, with gitconfig diff.submodule = short
+    Blame(String, Option<String>), // In a line of `git blame` output (commit, repeat_blame_line).
     Unknown,
     // The following elements are created when a line is wrapped to display it:
     HunkZeroWrapped,  // Wrapped unchanged line
@@ -67,6 +69,7 @@ pub struct StateMachine<'a> {
     // avoid emitting the file meta header line twice (#245).
     pub current_file_pair: Option<(String, String)>,
     pub handled_file_meta_header_line_file_pair: Option<(String, String)>,
+    pub blame_commit_colors: HashMap<String, String>,
 }
 
 pub fn delta<I>(lines: ByteLines<I>, writer: &mut dyn Write, config: &Config) -> std::io::Result<()>
@@ -92,6 +95,7 @@ impl<'a> StateMachine<'a> {
             handled_file_meta_header_line_file_pair: None,
             painter: Painter::new(writer, config),
             config,
+            blame_commit_colors: HashMap::new(),
         }
     }
 
@@ -116,6 +120,7 @@ impl<'a> StateMachine<'a> {
                 || self.handle_submodule_log_line()?
                 || self.handle_submodule_short_line()?
                 || self.handle_hunk_line()?
+                || self.handle_blame_line()?
                 || self.should_skip_line()
                 || self.emit_line_unchanged()?;
         }

src/features/line_numbers.rs

@@ -266,14 +266,22 @@ fn format_and_paint_line_number_field<'a>(
             .as_ref()
             .unwrap_or(&Align::Center);
         match placeholder.placeholder {
-            Some(Placeholder::NumberMinus) => ansi_strings.push(styles[Minus].paint(
-                format_line_number(line_numbers[Minus], alignment_spec, width, None, config),
-            )),
+            Some(Placeholder::NumberMinus) => {
+                ansi_strings.push(styles[Minus].paint(format_line_number(
+                    line_numbers[Minus],
+                    alignment_spec,
+                    width,
+                    placeholder.precision,
+                    None,
+                    config,
+                )))
+            }
             Some(Placeholder::NumberPlus) => {
                 ansi_strings.push(styles[Plus].paint(format_line_number(
                     line_numbers[Plus],
                     alignment_spec,
                     width,
+                    placeholder.precision,
                     Some(plus_file),
                     config,
                 )))
@@ -292,10 +300,11 @@ fn format_line_number(
     line_number: Option<usize>,
     alignment: &Align,
     width: usize,
+    precision: Option<usize>,
     plus_file: Option<&str>,
     config: &config::Config,
 ) -> String {
-    let pad = |n| format::pad(n, width, alignment);
+    let pad = |n| format::pad(n, width, alignment, precision);
     match (line_number, config.hyperlinks, plus_file) {
         (None, _, _) => pad(""),
         (Some(n), true, Some(file)) => {
@@ -332,6 +341,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberMinus),
                 alignment_spec: None,
                 width: None,
+                precision: None,
                 suffix: "".into(),
                 prefix_len: 0,
                 suffix_len: 0,
@@ -348,6 +358,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberPlus),
                 alignment_spec: None,
                 width: Some(4),
+                precision: None,
                 suffix: "".into(),
                 prefix_len: 0,
                 suffix_len: 0,
@@ -364,6 +375,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberPlus),
                 alignment_spec: Some(Align::Right),
                 width: Some(4),
+                precision: None,
                 suffix: "".into(),
                 prefix_len: 0,
                 suffix_len: 0,
@@ -380,6 +392,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberPlus),
                 alignment_spec: Some(Align::Right),
                 width: Some(4),
+                precision: None,
                 suffix: "".into(),
                 prefix_len: 0,
                 suffix_len: 0,
@@ -396,6 +409,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberPlus),
                 alignment_spec: Some(Align::Right),
                 width: Some(4),
+                precision: None,
                 suffix: "@@".into(),
                 prefix_len: 2,
                 suffix_len: 2,
@@ -413,6 +427,7 @@ pub mod tests {
                     placeholder: Some(Placeholder::NumberMinus),
                     alignment_spec: Some(Align::Left),
                     width: Some(3),
+                    precision: None,
                     suffix: "@@---{np:_>4}**".into(),
                     prefix_len: 2,
                     suffix_len: 15,
@@ -422,6 +437,7 @@ pub mod tests {
                     placeholder: Some(Placeholder::NumberPlus),
                     alignment_spec: Some(Align::Right),
                     width: Some(4),
+                    precision: None,
                     suffix: "**".into(),
                     prefix_len: 5,
                     suffix_len: 2,
@@ -439,6 +455,7 @@ pub mod tests {
                 placeholder: None,
                 alignment_spec: None,
                 width: None,
+                precision: None,
                 suffix: "__@@---**".into(),
                 prefix_len: 0,
                 suffix_len: 9,
@@ -455,12 +472,14 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberMinus),
                 alignment_spec: Some(Align::Left),
                 width: Some(4),
+                precision: None,
                 suffix: "|".into(),
                 prefix_len: 2,
                 suffix_len: 1,
             }]
         );
     }
+
     #[test]
     fn test_line_number_format_odd_width_two() {
         assert_eq!(
@@ -475,6 +494,7 @@ pub mod tests {
                     placeholder: Some(Placeholder::NumberMinus),
                     alignment_spec: Some(Align::Left),
                     width: Some(4),
+                    precision: None,
                     suffix: "+{np:<4}|".into(),
                     prefix_len: 2,
                     suffix_len: 9,
@@ -484,6 +504,7 @@ pub mod tests {
                     placeholder: Some(Placeholder::NumberPlus),
                     alignment_spec: Some(Align::Left),
                     width: Some(4),
+                    precision: None,
                     suffix: "|".into(),
                     prefix_len: 1,
                     suffix_len: 1,
@@ -500,6 +521,7 @@ pub mod tests {
                 placeholder: None,
                 alignment_spec: None,
                 width: None,
+                precision: None,
                 suffix: "|++|".into(),
                 prefix_len: 1,
                 suffix_len: 4,
@@ -522,6 +544,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberMinus),
                 alignment_spec: None,
                 width: None,
+                precision: None,
                 suffix: long.into(),
                 suffix_len: long.len(),
             },]