Pointer

pointer is returned by new

A debug experience on pointer in Go.

        strategies := new(Config)   //new return a pointer to type Config
-       err = json.Unmarshal([]byte(strategyJsonStr), &strategies)
+       err = json.Unmarshal([]byte(strategyJsonStr), strategies)

-       return &strategies, nil
+       return *strategies, nil
 }


-       strategies := new(Config)
+       var strategies Config
        err = json.Unmarshal([]byte(strategyJsonStr), &strategies)

-       return &strategies, nil
+       return strategies, nil

This is a segment of code in ingress-nginx project, json.Unmarshal() need a pointer argument, the old code use &strategies which seems is fine.
But When run e2e tests it failed.

[eric@localhost ingress-nginx]$ PKG="k8s.io/ingress-nginx/internal/ingress/annotations/servicematch" ./build/test.sh
=== RUN   TestIngressAnnotationServiceMatchCookie
--- FAIL: TestIngressAnnotationServiceMatchCookie (0.00s)
        main_test.go:75: expected a Config type
        main_test.go:76: expected a Config got %!s(**servicematch.Config=0xc420078118)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]

Simple debug code can be added as below:

<       //t.Errorf("expected a Config got %T", cfg)
<       //t.Errorf("expected a Config got %s", cfg)