fix: respect OAS3 parameter default values (#4561)

* add test cases

* refactor default setters into own function

* reach into `schema` for default value in OAS3

* remove exclusive test

test/bugs/4557-default-parameter-values.js

@@ -0,0 +1,67 @@
+/* eslint-env mocha */
+import React from "react"
+import { List, fromJS } from "immutable"
+import expect, { createSpy } from "expect"
+import { render } from "enzyme"
+import ParameterRow from "components/parameter-row"
+
+describe("bug #4557: default parameter values", function(){
+  it("should apply a Swagger 2.0 default value", function(){
+
+    const paramValue = fromJS({
+      description: "a pet",
+      type: "string",
+      default: "MyDefaultValue"
+    })
+
+    let props = {
+      getComponent: ()=> "div",
+      specSelectors: {
+        security(){},
+        parameterWithMeta(){ return paramValue },
+        isOAS3(){ return false }
+      },
+      operation: {get: ()=>{}},
+      onChange: createSpy(),
+      param: paramValue,
+      onChangeConsumes: () => {},
+      pathMethod: [],
+      getConfigs: () => { return {} },
+      specPath: List([])
+    }
+
+    render(<ParameterRow {...props}/>)
+
+    expect(props.onChange).toHaveBeenCalledWith(paramValue, "MyDefaultValue")
+  })
+  it("should apply an OpenAPI 3.0 default value", function(){
+
+    const paramValue = fromJS({
+      description: "a pet",
+      schema: {
+        type: "string",
+        default: "MyDefaultValue"
+      }
+    })
+
+    let props = {
+      getComponent: ()=> "div",
+      specSelectors: {
+        security(){},
+        parameterWithMeta(){ return paramValue },
+        isOAS3(){ return true }
+      },
+      operation: {get: ()=>{}},
+      onChange: createSpy(),
+      param: paramValue,
+      onChangeConsumes: () => {},
+      pathMethod: [],
+      getConfigs: () => { return {} },
+      specPath: List([])
+    }
+
+    render(<ParameterRow {...props}/>)
+
+    expect(props.onChange).toHaveBeenCalledWith(paramValue, "MyDefaultValue")
+  })
+})