Add wrapper func for spew.Sprintf in utils

dump/dump.go

@@ -0,0 +1,34 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package dump
+
+import (
+	"github.com/davecgh/go-spew/spew"
+)
+
+var prettyPrintConfig = &spew.ConfigState{
+	Indent:                  "  ",
+	DisableMethods:          true,
+	DisablePointerAddresses: true,
+	DisableCapacities:       true,
+}
+
+// PrettyPrintObject wrap the spew.Sdump with Indent, and disabled methods like error() and String()
+// The output may change over time, so for guaranteed output please take more direct control
+func PrettyPrintObject(a interface{}) string {
+	return prettyPrintConfig.Sdump(a)
+}

dump/dump_test.go

@@ -0,0 +1,152 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package dump
+
+import (
+	"fmt"
+	"testing"
+)
+
+func ptrint(i int) *int {
+	return &i
+}
+
+func ptrstr(s string) *string {
+	return &s
+}
+
+// custom type to test Stringer interface on non-pointer receiver.
+type customString string
+
+// String implements the Stringer interface for testing invocation
+func (s customString) String() string {
+	return "custom string " + string(s)
+}
+
+// custom type to test error interface on non-pointer receiver.
+type customError int
+
+// Error implements the error interface for testing invocation
+func (e customError) Error() string {
+	return fmt.Sprintf("custom error: %d", int(e))
+}
+
+// custom type to test Stringer interface on pointer receiver.
+type pCustomString string
+
+// String implements the Stringer interface for testing invocation
+func (s *pCustomString) String() string {
+	return "custom string " + string(*s)
+}
+
+// custom type to test error interface on pointer receiver.
+type pCustomError int
+
+// Error implements the error interface for testing invocation
+func (e *pCustomError) Error() string {
+	return fmt.Sprintf("custom error: %d", int(*e))
+}
+
+// embed is used to test embedded structures.
+type embed struct {
+	s string
+}
+
+// embedwrap is used to test embedded structures.
+type embedwrap struct {
+	embed
+	e *embed
+}
+
+func TestPrettyPrintObject(t *testing.T) {
+	tcs := customString("test")
+	tpcs := pCustomString("&test")
+
+	tce := customError(0)
+	tpce := pCustomError(0)
+
+	teb := embed{"test"}
+	tebw := embedwrap{teb, &teb}
+
+	testCases := []struct {
+		a    interface{}
+		want string
+	}{
+		{int8(93), "(int8) 93\n"},
+		{int16(93), "(int16) 93\n"},
+		{int32(93), "(int32) 93\n"},
+		{int64(93), "(int64) 93\n"},
+		{int(-93), "(int) -93\n"},
+		{int8(-93), "(int8) -93\n"},
+		{int16(-93), "(int16) -93\n"},
+		{int32(-93), "(int32) -93\n"},
+		{int64(-93), "(int64) -93\n"},
+		{uint(93), "(uint) 93\n"},
+		{uint8(93), "(uint8) 93\n"},
+		{uint16(93), "(uint16) 93\n"},
+		{uint32(93), "(uint32) 93\n"},
+		{uint64(93), "(uint64) 93\n"},
+		{uintptr(93), "(uintptr) 0x5d\n"},
+		{ptrint(93), "(*int)(93)\n"},
+		{float32(93.76), "(float32) 93.76\n"},
+		{float64(93.76), "(float64) 93.76\n"},
+		{complex64(93i), "(complex64) (0+93i)\n"},
+		{complex128(93i), "(complex128) (0+93i)\n"},
+		{bool(true), "(bool) true\n"},
+		{bool(false), "(bool) false\n"},
+		{string("test"), "(string) (len=4) \"test\"\n"},
+		{ptrstr("test"), "(*string)((len=4) \"test\")\n"},
+		{[1]string{"arr"}, "([1]string) (len=1) {\n  (string) (len=3) \"arr\"\n}\n"},
+		{[]string{"slice"}, "([]string) (len=1) {\n  (string) (len=5) \"slice\"\n}\n"},
+		{tcs, "(dump.customString) (len=4) \"test\"\n"},
+		{&tcs, "(*dump.customString)((len=4) \"test\")\n"},
+		{tpcs, "(dump.pCustomString) (len=5) \"&test\"\n"},
+		{&tpcs, "(*dump.pCustomString)((len=5) \"&test\")\n"},
+		{tce, "(dump.customError) 0\n"},
+		{&tce, "(*dump.customError)(0)\n"},
+		{tpce, "(dump.pCustomError) 0\n"},
+		{&tpce, "(*dump.pCustomError)(0)\n"},
+		{
+			struct {
+				arr   [1]string
+				slice []string
+				m     map[string]int
+			}{
+				[1]string{"arr"},
+				[]string{"slice"},
+				map[string]int{"one": 1},
+			},
+			"(struct { arr [1]string; slice []string; m map[string]int }) {\n  arr: ([1]string) (len=1) {\n    (string) (len=3) \"arr\"\n  },\n  slice: ([]string) (len=1) {\n    (string) (len=5) \"slice\"\n  },\n  m: (map[string]int) (len=1) {\n    (string) (len=3) \"one\": (int) 1\n  }\n}\n",
+		},
+		{teb, "(dump.embed) {\n  s: (string) (len=4) \"test\"\n}\n"},
+		{tebw, "(dump.embedwrap) {\n  embed: (dump.embed) {\n    s: (string) (len=4) \"test\"\n  },\n  e: (*dump.embed)({\n    s: (string) (len=4) \"test\"\n  })\n}\n"},
+		{map[string]int{}, "(map[string]int) {\n}\n"},
+		{map[string]int{"one": 1}, "(map[string]int) (len=1) {\n  (string) (len=3) \"one\": (int) 1\n}\n"},
+		{map[string]interface{}{"one": 1}, "(map[string]interface {}) (len=1) {\n  (string) (len=3) \"one\": (int) 1\n}\n"},
+		{map[string]customString{"key": tcs}, "(map[string]dump.customString) (len=1) {\n  (string) (len=3) \"key\": (dump.customString) (len=4) \"test\"\n}\n"},
+		{map[string]customError{"key": tce}, "(map[string]dump.customError) (len=1) {\n  (string) (len=3) \"key\": (dump.customError) 0\n}\n"},
+		{map[string]embed{"key": teb}, "(map[string]dump.embed) (len=1) {\n  (string) (len=3) \"key\": (dump.embed) {\n    s: (string) (len=4) \"test\"\n  }\n}\n"},
+		{map[string]embedwrap{"key": tebw}, "(map[string]dump.embedwrap) (len=1) {\n  (string) (len=3) \"key\": (dump.embedwrap) {\n    embed: (dump.embed) {\n      s: (string) (len=4) \"test\"\n    },\n    e: (*dump.embed)({\n      s: (string) (len=4) \"test\"\n    })\n  }\n}\n"},
+	}
+
+	for i, tc := range testCases {
+		s := PrettyPrintObject(tc.a)
+		if tc.want != s {
+			t.Errorf("[%d]:\n\texpected %q\n\tgot      %q", i, tc.want, s)
+		}
+	}
+}