fix: Actually use latest version of bun when no project version is found

Before, we weren't actually looking up the latest local version, just
grabbing the first version returned by listing files in the `~/.bunv`
dir.

Author: aklinker1

src/vm.zig

@@ -37,6 +37,15 @@ pub fn getInstalledVersions(allocator: mem.Allocator, config_dir: []const u8) !s
         }
     }
 
+    // Sort by semantic version
+    mem.sort([]const u8, result.items, {}, struct {
+        fn lessThan(_: void, a: []const u8, b: []const u8) bool {
+            const semver_a = std.SemanticVersion.parse(a) catch return true;
+            const semver_b = std.SemanticVersion.parse(b) catch return false;
+            return semver_a.order(semver_b) == .lt;
+        }
+    }.lessThan);
+
     return result;
 }
 
@@ -107,8 +116,11 @@ pub fn getLatestLocalVersion(allocator: mem.Allocator, is_debug: bool, config_di
     if (installed_versions.items.len == 0) {
         return null;
     }
-    // TODO: installed versions are not sorted, so naively assuming the first item is the latest is wrong.
-    return try allocator.dupe(u8, installed_versions.items[0]);
+
+    // Versions are sorted, so the last item is the latest
+    const latest = installed_versions.items[installed_versions.items.len - 1];
+    if (is_debug) std.debug.print("Latest local version: {s}\n", .{latest});
+    return try allocator.dupe(u8, latest);
 }
 
 pub fn getLatestRemoteVersion(allocator: mem.Allocator, is_debug: bool) ![]const u8 {