diff --git a/src/update/detector.rs b/src/update/detector.rs
index 20727e7f..e5b92472 100644
--- a/src/update/detector.rs
+++ b/src/update/detector.rs
@@ -147,3 +147,47 @@ fn has_pacman_installation() -> bool {
 fn has_pacman_installation() -> bool {
 	false
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn test_install_method_display() {
+		assert_eq!(InstallMethod::Cargo.to_string(), "cargo");
+		assert_eq!(InstallMethod::Homebrew.to_string(), "homebrew");
+		assert_eq!(InstallMethod::Apt.to_string(), "apt");
+		assert_eq!(InstallMethod::Dnf.to_string(), "dnf");
+		assert_eq!(InstallMethod::Pacman.to_string(), "pacman");
+		assert_eq!(InstallMethod::Windows.to_string(), "windows");
+		assert_eq!(InstallMethod::Scoop.to_string(), "scoop");
+		assert_eq!(
+			InstallMethod::Chocolatey.to_string(),
+			"chocolatey"
+		);
+		assert_eq!(
+			InstallMethod::ScoopBucket.to_string(),
+			"scoop-bucket"
+		);
+		assert_eq!(InstallMethod::Unknown.to_string(), "unknown");
+	}
+
+	#[test]
+	fn test_install_method_equality() {
+		assert_eq!(InstallMethod::Cargo, InstallMethod::Cargo);
+		assert_ne!(InstallMethod::Cargo, InstallMethod::Dnf);
+	}
+
+	#[test]
+	fn test_install_method_clone() {
+		let method = InstallMethod::Dnf;
+		let cloned = method.clone();
+		assert_eq!(method, cloned);
+	}
+
+	#[test]
+	fn test_install_method_debug() {
+		let debug_str = format!("{:?}", InstallMethod::Cargo);
+		assert!(debug_str.contains("Cargo"));
+	}
+}
diff --git a/src/update/mod.rs b/src/update/mod.rs
index b217d928..2077eff4 100644
--- a/src/update/mod.rs
+++ b/src/update/mod.rs
@@ -168,3 +168,64 @@ fn confirm(prompt: &str) -> Result<bool> {
 
 	Ok(input.trim().eq_ignore_ascii_case("y"))
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+
+	#[test]
+	fn test_is_prerelease_nightly() {
+		assert!(is_prerelease("0.28.1-nightly"));
+		assert!(is_prerelease("0.28.1-NIGHTLY"));
+	}
+
+	#[test]
+	fn test_is_prerelease_rc() {
+		assert!(is_prerelease("0.28.1-rc.1"));
+		assert!(is_prerelease("0.28.1-RC.1"));
+	}
+
+	#[test]
+	fn test_is_prerelease_beta() {
+		assert!(is_prerelease("0.28.1-beta"));
+		assert!(is_prerelease("0.28.0-beta.2"));
+	}
+
+	#[test]
+	fn test_is_prerelease_alpha() {
+		assert!(is_prerelease("0.28.1-alpha"));
+		assert!(is_prerelease("0.28.0-alpha.1"));
+	}
+
+	#[test]
+	fn test_is_prerelease_dev() {
+		assert!(is_prerelease("0.28.1-dev"));
+		assert!(is_prerelease("0.28.0-dev.20240101"));
+	}
+
+	#[test]
+	fn test_is_prerelease_preview() {
+		assert!(is_prerelease("0.28.1-preview"));
+		assert!(is_prerelease("0.28.0-preview.3"));
+	}
+
+	#[test]
+	fn test_is_prerelease_snapshot() {
+		assert!(is_prerelease("0.28.1-snapshot"));
+	}
+
+	#[test]
+	fn test_is_not_prerelease_stable() {
+		assert!(!is_prerelease("0.28.1"));
+		assert!(!is_prerelease("0.28.0"));
+		assert!(!is_prerelease("1.0.0"));
+	}
+
+	#[test]
+	fn test_is_not_prerelease_version_with_prerelease_substring() {
+		// Ensure we don't false-positive on versions that contain prerelease keywords
+		// but aren't actually prereleases (e.g., "0.28.1-nightly-feature" wouldn't be valid anyway)
+		assert!(is_prerelease("0.28.1-nightly"));
+		assert!(!is_prerelease("0.28.1"));
+	}
+}