feat: added truncation_length/symbol to git_branch (#268)

Git branches can become very long (e.g. gitlab auto-generated branch
names), thus it would be nice to be able to truncate them to keep your
prompt lenght in line.

This patch adds two new options to the git_branch module:
* truncation_length: The amount of graphemes to of a gitbranch to
truncate to
* truncation_symbol: The symbol that should be used to indicate that a
branch name was trunctated

To be able to correctly work with UTF-8 graphemes, unicode-segmentation
was added as a dependency.

1 files changed, 168 insertions, 0 deletions

diff --git a/tests/testsuite/git_branch.rs b/tests/testsuite/git_branch.rs
new file mode 100644
index 000000000..16d889b4d
--- /dev/null
+++ b/tests/testsuite/git_branch.rs
@@ -0,0 +1,168 @@
+use ansi_term::Color;
+use git2::Repository;
+use std::env;
+use std::io;
+use std::process::Command;
+
+use crate::common::{self, TestCommand};
+
+#[test]
+fn test_changed_truncation_symbol() -> io::Result<()> {
+    test_truncate_length_with_config(
+        "1337_hello_world",
+        15,
+        "1337_hello_worl",
+        "%",
+        "truncation_symbol = \"%\"",
+    )
+}
+
+#[test]
+fn test_no_truncation_symbol() -> io::Result<()> {
+    test_truncate_length_with_config(
+        "1337_hello_world",
+        15,
+        "1337_hello_worl",
+        "",
+        "truncation_symbol = \"\"",
+    )
+}
+
+#[test]
+fn test_multi_char_truncation_symbol() -> io::Result<()> {
+    test_truncate_length_with_config(
+        "1337_hello_world",
+        15,
+        "1337_hello_worl",
+        "a",
+        "truncation_symbol = \"apple\"",
+    )
+}
+
+#[test]
+fn test_ascii_boundary_below() -> io::Result<()> {
+    test_truncate_length("1337_hello_world", 15, "1337_hello_worl", "…")
+}
+
+#[test]
+fn test_ascii_boundary_on() -> io::Result<()> {
+    test_truncate_length("1337_hello_world", 16, "1337_hello_world", "")
+}
+
+#[test]
+fn test_ascii_boundary_above() -> io::Result<()> {
+    test_truncate_length("1337_hello_world", 17, "1337_hello_world", "")
+}
+
+#[test]
+fn test_one() -> io::Result<()> {
+    test_truncate_length("1337_hello_world", 1, "1", "…")
+}
+
+#[test]
+fn test_zero() -> io::Result<()> {
+    test_truncate_length("1337_hello_world", 0, "1337_hello_world", "")
+}
+
+#[test]
+fn test_negative() -> io::Result<()> {
+    test_truncate_length("1337_hello_world", -1, "1337_hello_world", "")
+}
+
+#[test]
+fn test_hindi_truncation() -> io::Result<()> {
+    test_truncate_length("नमस्ते", 3, "नमस्", "…")
+}
+
+#[test]
+fn test_hindi_truncation2() -> io::Result<()> {
+    test_truncate_length("नमस्त", 3, "नमस्", "…")
+}
+
+#[test]
+fn test_japanese_truncation() -> io::Result<()> {
+    test_truncate_length("がんばってね", 4, "がんばっ", "…")
+}
+
+fn test_truncate_length(
+    branch_name: &str,
+    truncate_length: i64,
+    expected_name: &str,
+    truncation_symbol: &str,
+) -> io::Result<()> {
+    return test_truncate_length_with_config(
+        branch_name,
+        truncate_length,
+        expected_name,
+        truncation_symbol,
+        "",
+    );
+}
+
+fn test_truncate_length_with_config(
+    branch_name: &str,
+    truncate_length: i64,
+    expected_name: &str,
+    truncation_symbol: &str,
+    config_options: &str,
+) -> io::Result<()> {
+    let fixture_repo_dir = create_fixture_repo()?;
+    let repo_dir = common::new_tempdir()?.path().join("rocket");
+
+    Repository::clone(fixture_repo_dir.to_str().unwrap(), &repo_dir.as_path()).unwrap();
+    Command::new("git")
+        .args(&["checkout", "-b", branch_name])
+        .current_dir(repo_dir.as_path())
+        .output()?;
+
+    let output = common::render_module("git_branch")
+        .use_config(
+            toml::from_str(&format!(
+                "
+                    [git_branch]
+                        truncation_length = {}
+                        {}
+                ",
+                truncate_length, config_options
+            ))
+            .unwrap(),
+        )
+        .arg("--path")
+        .arg(repo_dir)
+        .output()?;
+    let actual = String::from_utf8(output.stdout).unwrap();
+
+    let expected = format!(
+        "on {} ",
+        Color::Purple
+            .bold()
+            .paint(format!("\u{e0a0} {}{}", expected_name, truncation_symbol)),
+    );
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+fn create_fixture_repo() -> io::Result<std::path::PathBuf> {
+    let fixture_repo_dir = common::new_tempdir()?.path().join("fixture");
+    let fixture = env::current_dir()?.join("tests/fixtures/rocket.bundle");
+
+    Command::new("git")
+        .args(&["config", "--global", "user.email", "starship@example.com"])
+        .output()?;
+
+    Command::new("git")
+        .args(&["config", "--global", "user.name", "starship"])
+        .output()?;
+
+    Command::new("git")
+        .args(&[
+            "clone",
+            "-b",
+            "master",
+            &fixture.to_str().unwrap(),
+            fixture_repo_dir.to_str().unwrap(),
+        ])
+        .output()?;
+
+    Ok(fixture_repo_dir)
+}