feat: add support for go modules

Signed-off-by: Luke-zhang-04 <[email protected]>

Author: Luke-zhang-04

src/onefetch/deps.rs

@@ -1,17 +1,20 @@
 use {
     crate::onefetch::error::*,
+    regex::Regex,
     std::collections::HashMap,
     std::{ffi::OsStr, fs},
 };
 
 pub enum PackageManager {
     Npm,
+    GoModules,
 }
 
 impl std::fmt::Display for PackageManager {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match *self {
             PackageManager::Npm => write!(f, "Npm"),
+            PackageManager::GoModules => write!(f, "Go Modules"),
         }
     }
 }
@@ -28,11 +31,21 @@ fn npm(contents: &str) -> Option<i32> {
     Some(parsed["dependencies"].len() as i32)
 }
 
+fn gomodules(contents: &str) -> Option<i32> {
+    let count = Regex::new(r"v[0-9].").unwrap().find_iter(contents).count();
+
+    Some(count as i32)
+}
+
 impl Detector {
     pub fn new() -> Self {
         let mut package_managers: HashMap<String, (DependencyParser, PackageManager)> =
             HashMap::new();
         package_managers.insert(String::from("package.json"), (npm, PackageManager::Npm));
+        package_managers.insert(
+            String::from("go.mod"),
+            (gomodules, PackageManager::GoModules),
+        );
 
         Self { package_managers }
     }