fix(spec): set multi-value parameters as an immutable list (#9567)

Refs #9566

src/core/plugins/spec/reducers.js

@@ -62,7 +62,7 @@ export default {
 
     return state.setIn(
       ["meta", "paths", ...pathMethod, "parameters", paramKey, valueKey],
-      value
+      fromJS(value)
     )
   },
 

test/unit/core/plugins/spec/reducer.js

@@ -1,5 +1,5 @@
 
-import { fromJS } from "immutable"
+import { fromJS, List } from "immutable"
 import reducer from "core/plugins/spec/reducers"
 
 describe("spec plugin - reducer", function(){
@@ -149,6 +149,7 @@ describe("spec plugin - reducer", function(){
       const response = result.getIn(["meta", "paths", path, method, "parameters", "body.myBody", "value"])
       expect(response).toEqual(`{ "a": 123 }`)
     })
+
     it("should store parameter values by identity", () => {
       const updateParam = reducer["spec_update_param"]
 
@@ -176,6 +177,27 @@ describe("spec plugin - reducer", function(){
       const value = result.getIn(["meta", "paths", path, method, "parameters", `body.myBody.hash-${param.hashCode()}`, "value"])
       expect(value).toEqual(`{ "a": 123 }`)
     })
+
+    it("should store a multi-value parameter as an immutable list", () => {
+      const updateParam = reducer["spec_update_param"]
+
+      const path = "/pet/post"
+      const method = "POST"
+
+      const state = fromJS({})
+      const result = updateParam(state, {
+        payload: {
+          path: [path, method],
+          paramName: "myBody",
+          paramIn: "body",
+          value: [ "a", "b" ],
+          isXml: false
+        }
+      })
+
+      const response = result.getIn(["meta", "paths", path, method, "parameters", "body.myBody", "value"])
+      expect(List.isList(response)).toEqual(true)
+    })
   })
   describe("SPEC_UPDATE_EMPTY_PARAM_INCLUSION", function() {
     it("should store parameter values by {in}.{name}", () => {