perf: freeze parse options to avoid object allocation

internal/parse-options.js

@@ -1,17 +1,41 @@
+const var1 = Object.freeze({ includePrerelease: true, loose: true, rtl: true });
+const var2 = Object.freeze({ includePrerelease: true, loose: true });
+const var3 = Object.freeze({ includePrerelease: true, rtl: true });
+const var4 = Object.freeze({ includePrerelease: true });
+const var5 = Object.freeze({ loose: true, rtl: true });
+const var6 = Object.freeze({ loose: true });
+const var7 = Object.freeze({ rtl: true });
+const emptyOpts = Object.freeze({});
+
 const parseOptions = options => {
-  if (!options) return {};
+  if (!options) return emptyOpts;
+
+  if (typeof options !== 'object') return var6;
 
-  if (typeof options !== 'object') return { loose: true };
+  if (options.includePrerelease) {
+    if (options.loose && options.rtl) {
+      return var1;
+    }
 
-  const parsedOptions = {};
+    if (options.loose) {
+      return var2;
+    }
 
-  // parse out just the options we care about so we always get a consistent
-  // obj with keys in a consistent order.
+    if (options.rtl) {
+      return var3;
+    }
 
-  if (options.includePrerelease) parsedOptions.includePrerelease = true;
-  if (options.loose) parsedOptions.loose = true;
-  if (options.rtl) parsedOptions.rtl = true;
+    return var4;
+  } else if (options.loose) {
+    if (options.rtl) {
+      return var5;
+    }
 
-  return parsedOptions;
+    return var6;
+  } else if (options.rtl) {
+    return var7;
+  } else {
+    return emptyOpts;
+  }
 };
 module.exports = parseOptions;