fix: faster parse options using cached objects

Author: H4ad

internal/parse-options.js

@@ -1,11 +1,51 @@
-// parse out just the options we care about so we always get a consistent
-// obj with keys in a consistent order.
-const opts = ['includePrerelease', 'loose', 'rtl']
-const parseOptions = options =>
-  !options ? {}
-  : typeof options !== 'object' ? { loose: true }
-  : opts.filter(k => options[k]).reduce((o, k) => {
-    o[k] = true
-    return o
-  }, {})
+// parse out just the options we care about
+const isParsedConfigSymbol = Symbol('isParsedConfig')
+const var1 = Object.freeze({ includePrerelease: true, loose: true, rtl: true, [isParsedConfigSymbol]: true })
+const var2 = Object.freeze({ includePrerelease: true, loose: true, [isParsedConfigSymbol]: true })
+const var3 = Object.freeze({ includePrerelease: true, rtl: true, [isParsedConfigSymbol]: true })
+const var4 = Object.freeze({ includePrerelease: true, [isParsedConfigSymbol]: true })
+const var5 = Object.freeze({ loose: true, rtl: true, [isParsedConfigSymbol]: true })
+const var6 = Object.freeze({ loose: true, [isParsedConfigSymbol]: true })
+const var7 = Object.freeze({ rtl: true, [isParsedConfigSymbol]: true })
+const emptyOpts = Object.freeze({ [isParsedConfigSymbol]: true })
+
+const parseOptions = options => {
+  if (!options) {
+    return emptyOpts
+  }
+
+  if (typeof options !== 'object') {
+    return var6
+  }
+
+  if (options[isParsedConfigSymbol]) {
+    return options
+  }
+
+  if (options.includePrerelease) {
+    if (options.loose && options.rtl) {
+      return var1
+    }
+
+    if (options.loose) {
+      return var2
+    }
+
+    if (options.rtl) {
+      return var3
+    }
+
+    return var4
+  } else if (options.loose) {
+    if (options.rtl) {
+      return var5
+    }
+
+    return var6
+  } else if (options.rtl) {
+    return var7
+  } else {
+    return emptyOpts
+  }
+}
 module.exports = parseOptions

test/internal/parse-options.js

@@ -27,5 +27,20 @@ t.test('objects only include truthy flags we know about, set to true', t => {
     rtl: true,
     includePrerelease: true,
   })
+  t.strictSame(parseOptions({ loose: true }), { loose: true })
+  t.strictSame(parseOptions({ rtl: true }), { rtl: true })
+  t.strictSame(parseOptions({ includePrerelease: true }), { includePrerelease: true })
+  t.strictSame(parseOptions({ loose: true, rtl: true }), { loose: true, rtl: true })
+  t.strictSame(parseOptions({ loose: true, includePrerelease: true }), { loose: true, includePrerelease: true })
+  t.strictSame(parseOptions({ rtl: true, includePrerelease: true }), { rtl: true, includePrerelease: true })
+  t.end()
+})
+
+t.test('should skip validation when options is already parsed', t => {
+  const options = { loose: true, rtl: true }
+  const parsedOptions = parseOptions(options)
+
+  t.equal(parseOptions(parsedOptions) === parsedOptions, true)
+  t.not(parseOptions(options) === parsedOptions, false)
   t.end()
 })