Check more dependencies, fix bug

Sources/Generator/Processing/DependencyCheck.swift

@@ -4,7 +4,14 @@ func checkDependencies() -> Bool {
     print("--- DEPENDENCIES -----------------------------------")
     print("                                                    ")
     defer { print("                                                    ") }
-    return checkImageOptimAvailability() && checkMagickAvailability() && checkCwebpAvailability() && checkAvifAvailability()
+    var valid = true
+    valid = checkImageOptimAvailability() && valid
+    valid = checkMagickAvailability() && valid
+    valid = checkCwebpAvailability() && valid
+    valid = checkAvifAvailability() && valid
+    valid = checkUglifyJsAvailability() && valid
+    valid = checkCleanCssAvailability() && valid
+    return valid
 }
 
 private func checkImageOptimAvailability() -> Bool {
@@ -73,3 +80,40 @@ private func checkAvifAvailability() -> Bool {
     }
     return true
 }
+
+
+private func checkUglifyJsAvailability() -> Bool {
+    do {
+        let output = try safeShell("uglifyjs --version")
+        let version = output.dropBeforeFirst("uglify-js").components(separatedBy: ".").compactMap { Int($0.trimmed) }
+        if version.count > 1 {
+            print("             uglify-js: \(version.map { "\($0)" }.joined(separator: "."))")
+        } else {
+            print("'\(output)'")
+            print("             uglify-js: Not found")
+            return false
+        }
+    } catch {
+        print("             uglify-js: Failed to get version (\(error))")
+        return false
+    }
+    return true
+}
+
+
+private func checkCleanCssAvailability() -> Bool {
+    do {
+        let output = try safeShell("cleancss --version")
+        let version = output.components(separatedBy: ".").compactMap { Int($0.trimmed) }
+        if version.count > 1 {
+            print("              cleancss: \(version.map { "\($0)" }.joined(separator: "."))")
+        } else {
+            print("              cleancss: Not found")
+            return false
+        }
+    } catch {
+        print("              cleancss: Failed to get version (\(error))")
+        return false
+    }
+    return true
+}