It appears that the repository has undergone several changes and renamings:

backend/node_modules/autoprefixer/lib/old-value.js

@@ -1,22 +0,0 @@
-let utils = require('./utils')
-
-class OldValue {
-  constructor(unprefixed, prefixed, string, regexp) {
-    this.unprefixed = unprefixed
-    this.prefixed = prefixed
-    this.string = string || prefixed
-    this.regexp = regexp || utils.regexp(prefixed)
-  }
-
-  /**
-   * Check, that value contain old value
-   */
-  check(value) {
-    if (value.includes(this.string)) {
-      return !!value.match(this.regexp)
-    }
-    return false
-  }
-}
-
-module.exports = OldValue