UniverLab
diff --git a/.gitignore b/.gitignore
@@ -19,3 +19,31 @@ skills-lock.json
 #/target
 *.mp4
 .mimocode/
+
+# AI coding agents
+.cursor/
+.windsurf/
+.claude/
+.continue/
+.copilot/
+.kilocode/
+.zencoder/
+.qwen/
+
+# AI coding agents
+
+# AI coding agents
+
+# AI coding agents
+
+# AI coding agents
+
+# AI coding agents
+
+# AI coding agents
+
+# AI coding agents
+
+# AI coding agents
+
+# AI coding agents
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -20,6 +20,7 @@ toml = "0.8"
 ureq = "2"
 
 [dev-dependencies]
+serial_test = "3.5.0"
 tempfile = "3"
 
 [dependencies.inquire]

diff --git a/src/attributes/mod.rs b/src/attributes/mod.rs
@@ -64,9 +64,8 @@ pub fn run(cmd: AttributesCommand) -> Result<()> {
     Ok(())
 }
 
-/// Apply one or more attribute presets by label. Used by the interactive wizard.
-pub(crate) fn apply_presets(labels: &[&str]) -> Result<()> {
-    let root = find_repo_root()?;
+/// Apply one or more attribute presets by label at a given root. Used by the interactive wizard.
+pub(crate) fn apply_presets_at(labels: &[&str], root: &std::path::Path) -> Result<()> {
     let path = root.join(".gitattributes");
     let existing = if path.exists() {
         fs::read_to_string(&path).unwrap_or_default()
@@ -91,6 +90,12 @@ pub(crate) fn apply_presets(labels: &[&str]) -> Result<()> {
     Ok(())
 }
 
+/// Apply presets using CWD to find repo root.
+pub(crate) fn apply_presets(labels: &[&str]) -> Result<()> {
+    let root = find_repo_root()?;
+    apply_presets_at(labels, &root)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -123,4 +128,88 @@ mod tests {
     fn attributes_binary_preset_marks_png() {
         assert!(PRESET_BINARY.contains("*.png binary"));
     }
+
+    #[test]
+    fn apply_presets_line_endings_writes_content() {
+        let dir = make_git_repo();
+        let path = dir.path().join(".gitattributes");
+        fs::write(&path, "").unwrap();
+        let result = apply_presets_at(&["line-endings"], dir.path());
+        assert!(result.is_ok());
+        let content = fs::read_to_string(&path).unwrap();
+        assert!(content.contains("eol=lf"));
+    }
+
+    #[test]
+    fn apply_presets_binary_files_writes_content() {
+        let dir = make_git_repo();
+        let path = dir.path().join(".gitattributes");
+        fs::write(&path, "").unwrap();
+        let result = apply_presets_at(&["binary-files"], dir.path());
+        assert!(result.is_ok());
+        let content = fs::read_to_string(&path).unwrap();
+        assert!(content.contains("*.png binary"));
+    }
+
+    #[test]
+    fn apply_presets_both_presets() {
+        let dir = make_git_repo();
+        let path = dir.path().join(".gitattributes");
+        fs::write(&path, "").unwrap();
+        let result = apply_presets_at(&["line-endings", "binary-files"], dir.path());
+        assert!(result.is_ok());
+        let content = fs::read_to_string(&path).unwrap();
+        assert!(content.contains("eol=lf"));
+        assert!(content.contains("*.png binary"));
+    }
+
+    #[test]
+    fn apply_presets_skips_unknown_labels() {
+        let dir = make_git_repo();
+        let path = dir.path().join(".gitattributes");
+        fs::write(&path, "").unwrap();
+        let result = apply_presets_at(&["unknown-preset"], dir.path());
+        assert!(result.is_ok());
+        let content = fs::read_to_string(&path).unwrap();
+        assert!(content.is_empty());
+    }
+
+    #[test]
+    fn apply_presets_does_not_duplicate() {
+        let dir = make_git_repo();
+        let path = dir.path().join(".gitattributes");
+        fs::write(&path, "* text=auto eol=lf\n").unwrap();
+        let result = apply_presets_at(&["line-endings"], dir.path());
+        assert!(result.is_ok());
+        let content = fs::read_to_string(&path).unwrap();
+        assert_eq!(content.matches("eol=lf").count(), 1);
+    }
+
+    #[test]
+    fn apply_presets_appends_to_existing_content() {
+        let dir = make_git_repo();
+        let path = dir.path().join(".gitattributes");
+        fs::write(&path, "# custom\n*.txt text\n").unwrap();
+        let result = apply_presets_at(&["line-endings"], dir.path());
+        assert!(result.is_ok());
+        let content = fs::read_to_string(&path).unwrap();
+        assert!(content.contains("# custom"));
+        assert!(content.contains("*.txt text"));
+        assert!(content.contains("eol=lf"));
+    }
+
+    #[test]
+    fn preset_binary_all_expected_extensions() {
+        let extensions = [
+            "png", "jpg", "jpeg", "gif", "ico", "pdf", "zip", "tar", "gz", "wasm",
+        ];
+        for ext in &extensions {
+            assert!(PRESET_BINARY.contains(&format!("*.{ext} binary")));
+        }
+    }
+
+    #[test]
+    fn preset_lf_exact_content() {
+        assert_eq!(PRESET_LF, "* text=auto eol=lf\n");
+    }
 }