feature: allowEmptyValue controls (#4788)

* add baseline tests

* coerce empty strings to null when updating parameter values

* add ParameterIncludeEmpty

* add redux management for empty parameter value inclusion state

* use name+in keying for state management instead of hash keying

* update new redux method usages to name+in keying

* coerce empty Immutable iterables in onChangeWrapper

* OAS3 tests & support

* add included empty parameters to requests before dispatching to Swagger Client

* make empty inclusion interface prettier

* add tests for #4587

* linter fixes

* check for truthy value before reaching into property

test/core/plugins/spec/actions.js

@@ -1,7 +1,7 @@
 /* eslint-env mocha */
 import expect, { createSpy } from "expect"
 import { fromJS } from "immutable"
-import { execute, executeRequest, changeParamByIdentity } from "corePlugins/spec/actions"
+import { execute, executeRequest, changeParamByIdentity, updateEmptyParamInclusion } from "corePlugins/spec/actions"
 
 describe("spec plugin - actions", function(){
 
@@ -207,4 +207,22 @@ describe("spec plugin - actions", function(){
       })
     })
   })
+
+  describe("updateEmptyParamInclusion", function () {
+    it("should map its arguments to a payload", function () {
+      const pathMethod = ["/one", "get"]
+
+      const result = updateEmptyParamInclusion(pathMethod, "param", "query", true)
+
+      expect(result).toEqual({
+        type: "spec_update_empty_param_inclusion",
+        payload: {
+          pathMethod,
+          paramName: "param",
+          paramIn: "query",
+          includeEmptyValue: true
+        }
+      })
+    })
+  })
 })