Move internal modules to “internal” folder.

.internal/updateWrapDetails.js

@@ -0,0 +1,46 @@
+import arrayEach from './.internal/arrayEach.js';
+import arrayIncludes from './.internal/arrayIncludes.js';
+
+/** Used to compose bitmasks for function metadata. */
+const WRAP_BIND_FLAG = 1;
+const WRAP_BIND_KEY_FLAG = 2;
+const WRAP_CURRY_FLAG = 8;
+const WRAP_CURRY_RIGHT_FLAG = 16;
+const WRAP_PARTIAL_FLAG = 32;
+const WRAP_PARTIAL_RIGHT_FLAG = 64;
+const WRAP_ARY_FLAG = 128;
+const WRAP_REARG_FLAG = 256;
+const WRAP_FLIP_FLAG = 512;
+
+/** Used to associate wrap methods with their bit flags. */
+const wrapFlags = [
+  ['ary', WRAP_ARY_FLAG],
+  ['bind', WRAP_BIND_FLAG],
+  ['bindKey', WRAP_BIND_KEY_FLAG],
+  ['curry', WRAP_CURRY_FLAG],
+  ['curryRight', WRAP_CURRY_RIGHT_FLAG],
+  ['flip', WRAP_FLIP_FLAG],
+  ['partial', WRAP_PARTIAL_FLAG],
+  ['partialRight', WRAP_PARTIAL_RIGHT_FLAG],
+  ['rearg', WRAP_REARG_FLAG]
+];
+
+/**
+ * Updates wrapper `details` based on `bitmask` flags.
+ *
+ * @private
+ * @returns {Array} details The details to modify.
+ * @param {number} bitmask The bitmask flags. See `createWrap` for more details.
+ * @returns {Array} Returns `details`.
+ */
+function updateWrapDetails(details, bitmask) {
+  arrayEach(wrapFlags, pair => {
+    const value = `${ pair[0] }`;
+    if ((bitmask & pair[1]) && !arrayIncludes(details, value)) {
+      details.push(value);
+    }
+  });
+  return details.sort();
+}
+
+export default updateWrapDetails;