feat: Choose full diff based on terminal height

Author: quodlibetor

Cargo.lock

@@ -21,7 +21,9 @@ 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 }
+terminal_size = "0.3.0"
 syntect = "5.2.0"
+termcolor = "1.4.1"
 
 [dev-dependencies]
 assert_cmd = "2.0.13"

Cargo.toml

@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::io::Write as _;
 
 use anyhow::{anyhow, bail, Context};
 use console::style;
@@ -11,6 +12,8 @@ use syntect::easy::HighlightLines;
 use syntect::highlighting::ThemeSet;
 use syntect::parsing::SyntaxSet;
 use syntect::util::as_24_bit_terminal_escaped;
+use termcolor::{ColorChoice, StandardStream, WriteColor as _};
+use terminal_size::{terminal_size, Height};
 
 const DEFAULT_UPSTREAM_BRANCHES: &[&str] = &["main", "master", "develop", "trunk"];
 
@@ -248,11 +251,18 @@ fn create_diff(repo: &Repository, require_newline: bool) -> Result<Diff, anyhow:
     let diff = if diffstat.files_changed() == 0 {
         let dirty_workdir_stats = dirty_diff.stats()?;
         if dirty_workdir_stats.files_changed() > 0 {
+            let Height(h) = terminal_size().map(|(_w, h)| h).unwrap_or(Height(24));
+            let cutoff_height = (h - 5) as usize; // give some room for the prompt
             let total_change = dirty_workdir_stats.insertions() + dirty_workdir_stats.deletions();
-            if total_change < 50 {
-                native_diff(&dirty_diff)?;
-            } else {
+            if total_change >= cutoff_height {
                 print_diffstat("Unstaged", &dirty_diff)?;
+            } else {
+                let diff_lines = native_diff(&dirty_diff)?;
+                if diff_lines.len() >= cutoff_height {
+                    print_diffstat("Unstaged", &dirty_diff)?;
+                } else {
+                    print_diff_lines(&diff_lines)?;
+                }
             }
             if !Confirm::new()
                 .with_prompt("Nothing staged, stage and commit everything?")
@@ -419,13 +429,14 @@ fn format_ref(rf: &git2::Reference<'_>) -> Result<String, anyhow::Error> {
 
 // diff helpers
 
-fn native_diff(diff: &Diff<'_>) -> Result<(), anyhow::Error> {
+fn native_diff(diff: &Diff<'_>) -> 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 inner_err = None;
+    let mut diff_lines = Vec::new();
 
     diff.print(DiffFormat::Patch, |_delta, _hunk, line| {
         let content = std::str::from_utf8(line.content()).unwrap();
@@ -441,7 +452,7 @@ fn native_diff(diff: &Diff<'_>) -> Result<(), anyhow::Error> {
                     }
                 };
                 let escaped = as_24_bit_terminal_escaped(&ranges[..], true);
-                print!("{}", escaped);
+                diff_lines.push(escaped);
             }
             _ => {
                 let ranges = match h.highlight_line(content, &ss) {
@@ -452,7 +463,7 @@ fn native_diff(diff: &Diff<'_>) -> Result<(), anyhow::Error> {
                     }
                 };
                 let escaped = as_24_bit_terminal_escaped(&ranges[..], true);
-                print!("{}", escaped);
+                diff_lines.push(escaped);
             }
         }
         true
@@ -461,10 +472,20 @@ fn native_diff(diff: &Diff<'_>) -> Result<(), anyhow::Error> {
     if let Some(err) = inner_err {
         Err(err.into())
     } else {
-        Ok(())
+        Ok(diff_lines)
     }
 }
 
+fn print_diff_lines(diff_lines: &[String]) -> Result<(), anyhow::Error> {
+    let mut stdout = StandardStream::stdout(ColorChoice::Auto);
+    for line in diff_lines {
+        write!(&mut stdout, "{}", line)?;
+    }
+    stdout.reset()?;
+    writeln!(&mut stdout)?;
+    Ok(())
+}
+
 fn print_diffstat(prefix: &str, diff: &Diff<'_>) -> Result<(), anyhow::Error> {
     let buf = diff.stats()?.to_buf(DiffStatsFormat::FULL, 80)?;
     let stat = std::str::from_utf8(&buf).context("converting diffstat to utf-8")?;