refactor(oas31): introduce selector composition mechanism (#8484)

Refs #8474

src/core/plugins/oas31/fn.js

@@ -0,0 +1,50 @@
+/**
+ * @prettier
+ */
+
+export const isOAS31 = (jsSpec) => {
+  const oasVersion = jsSpec.get("openapi")
+
+  return (
+    typeof oasVersion === "string" && /^3\.1\.(?:[1-9]\d*|0)$/.test(oasVersion)
+  )
+}
+
+/**
+ * Creates selector that returns value of the original
+ * selector when spec is OpenAPI 3.1.0., null otherwise.
+ *
+ * @param selector
+ * @returns {function(*, ...[*]): function(*): (*|null)}
+ */
+export const createOnlyOAS31Selector =
+  (selector) =>
+  (state, ...args) =>
+  (system) => {
+    if (system.getSystem().specSelectors.isOAS31()) {
+      const selectedValue = selector(state, ...args)
+      return typeof selectedValue === "function"
+        ? selectedValue(system)
+        : selectedValue
+    } else {
+      return null
+    }
+  }
+
+/**
+ * Creates selector that provides system as the
+ * second argument. This allows to create memoized
+ * composed selectors from different plugins.
+ *
+ * @param selector
+ * @returns {function(*, ...[*]): function(*): *}
+ */
+export const createSystemSelector =
+  (selector) =>
+  (state, ...args) =>
+  (system) => {
+    const selectedValue = selector(state, system, ...args)
+    return typeof selectedValue === "function"
+      ? selectedValue(system)
+      : selectedValue
+  }