feat: Allow setting the diff theme

Author: quodlibetor

Cargo.toml

@@ -21,14 +21,14 @@ clap = { version = "4.5.1", features = ["derive", "env", "wrap_help"] }
 console = "0.15.8"
 dialoguer = "0.11.0"
 git2 = { version = "0.18.2", default-features = false }
+itertools = "0.12.1"
+termcolor = "1.4.1"
 terminal_size = "0.3.0"
 syntect = "5.2.0"
-termcolor = "1.4.1"
 
 [dev-dependencies]
 assert_cmd = "2.0.13"
 assert_fs = "1.1.1"
-itertools = "0.12.1"
 
 # The profile that 'cargo dist' will build with
 [profile.dist]

src/lib.rs

@@ -16,6 +16,7 @@ use termcolor::{ColorChoice, StandardStream, WriteColor as _};
 use terminal_size::{terminal_size, Height};
 
 const DEFAULT_UPSTREAM_BRANCHES: &[&str] = &["main", "master", "develop", "trunk"];
+pub const DEFAULT_THEME: &str = "base16-ocean.dark";
 
 pub struct Config {
     /// Change the commit message that you amend, instead of using the original commit message
@@ -27,11 +28,13 @@ pub struct Config {
     pub default_upstream_branch: Option<String>,
     /// Require a newline when confirming y/n questions
     pub require_newline: bool,
+    /// Which theme to use
+    pub theme: String,
 }
 
 pub fn instafix(c: Config) -> Result<(), anyhow::Error> {
     let repo = Repository::open(".").context("opening repo")?;
-    let diff = create_diff(&repo, c.require_newline).context("creating diff")?;
+    let diff = create_diff(&repo, &c.theme, c.require_newline).context("creating diff")?;
     let head = repo.head().context("finding head commit")?;
     let head_branch = Branch::wrap(head);
     let upstream = get_merge_base(&repo, &head_branch, c.default_upstream_branch.as_deref())
@@ -254,7 +257,11 @@ fn get_merge_base<'a>(
 }
 
 /// Get a diff either from the index or the diff from the index to the working tree
-fn create_diff(repo: &Repository, require_newline: bool) -> Result<Diff, anyhow::Error> {
+fn create_diff<'a>(
+    repo: &'a Repository,
+    theme: &str,
+    require_newline: bool,
+) -> Result<Diff<'a>, anyhow::Error> {
     let head = repo.head()?;
     let head_tree = head.peel_to_tree()?;
     let staged_diff = repo.diff_tree_to_index(Some(&head_tree), None, None)?;
@@ -269,7 +276,7 @@ fn create_diff(repo: &Repository, require_newline: bool) -> Result<Diff, anyhow:
             if total_change >= cutoff_height {
                 print_diffstat("Unstaged", &dirty_diff)?;
             } else {
-                let diff_lines = native_diff(&dirty_diff)?;
+                let diff_lines = native_diff(&dirty_diff, theme)?;
                 if diff_lines.len() >= cutoff_height {
                     print_diffstat("Unstaged", &dirty_diff)?;
                 } else {
@@ -439,13 +446,26 @@ fn format_ref(rf: &git2::Reference<'_>) -> Result<String, anyhow::Error> {
     Ok(format!("{} ({})", shorthand, &sha[..10]))
 }
 
+/// A vec of all built-in theme names
+pub fn print_themes() {
+    println!("Available themes:");
+    for theme in ThemeSet::load_defaults().themes.keys() {
+        println!("  {}", theme);
+    }
+}
+
 // diff helpers
 
-fn native_diff(diff: &Diff<'_>) -> Result<Vec<String>, anyhow::Error> {
+fn native_diff(diff: &Diff<'_>, theme: &str) -> Result<Vec<String>, anyhow::Error> {
     let ss = SyntaxSet::load_defaults_newlines();
     let ts = ThemeSet::load_defaults();
     let syntax = ss.find_syntax_by_extension("patch").unwrap();
-    let mut h = HighlightLines::new(syntax, &ts.themes["base16-ocean.dark"]);
+    let mut h = HighlightLines::new(
+        syntax,
+        ts.themes
+            .get(theme)
+            .unwrap_or_else(|| &ts.themes[DEFAULT_THEME]),
+    );
 
     let mut inner_err = None;
     let mut diff_lines = Vec::new();

src/main.rs

@@ -15,10 +15,12 @@
 use std::env;
 
 use clap::Parser;
+use git_instafix::DEFAULT_THEME;
 
 const MAX_COMMITS_VAR: &str = "GIT_INSTAFIX_MAX_COMMITS";
 const UPSTREAM_VAR: &str = "GIT_INSTAFIX_UPSTREAM";
 const REQUIRE_NEWLINE_VAR: &str = "GIT_INSTAFIX_REQUIRE_NEWLINE";
+const THEME_VAR: &str = "GIT_INSTAFIX_THEME";
 
 #[derive(Parser, Debug)]
 #[clap(
@@ -63,13 +65,25 @@ struct Args {
     /// [gitconfig: instafix.require-newline]
     #[clap(long, env = REQUIRE_NEWLINE_VAR)]
     require_newline: Option<bool>,
+
+    /// Show the possible color themes for output
+    #[clap(long)]
+    help_themes: bool,
+
+    /// Use this theme
+    #[clap(long, env = THEME_VAR)]
+    theme: Option<String>,
 }
 
 fn main() {
     let mut args = Args::parse();
     if env::args().next().unwrap().ends_with("squash") {
         args.squash = Some(true)
     }
+    if args.help_themes {
+        git_instafix::print_themes();
+        return;
+    }
     let config = args_to_config_using_git_config(args).unwrap();
     if let Err(e) = git_instafix::instafix(config) {
         // An empty message means don't display any error message
@@ -103,5 +117,9 @@ fn args_to_config_using_git_config(args: Args) -> Result<git_instafix::Config, a
         require_newline: args
             .require_newline
             .unwrap_or_else(|| cfg.get_bool("instafix.require-newline").unwrap_or(false)),
+        theme: args.theme.unwrap_or_else(|| {
+            cfg.get_string("instafix.theme")
+                .unwrap_or_else(|_| DEFAULT_THEME.to_string())
+        }),
     })
 }