From ceee04f4c6ade82ffc432b6e61627142814e8862 Mon Sep 17 00:00:00 2001
From: FFMMM <FFMMM@users.noreply.github.com>
Date: Thu, 24 Mar 2022 10:37:04 -0700
Subject: [PATCH] remove Telemetry.MergeDefaults (#12606)

Signed-off-by: FFMMM <FFMMM@users.noreply.github.com>
---
 lib/telemetry.go      | 52 -----------------------
 lib/telemetry_test.go | 99 -------------------------------------------
 2 files changed, 151 deletions(-)
 delete mode 100644 lib/telemetry_test.go

diff --git a/lib/telemetry.go b/lib/telemetry.go
index d85e51d45d..d74edb37cb 100644
--- a/lib/telemetry.go
+++ b/lib/telemetry.go
@@ -1,7 +1,6 @@
 package lib
 
 import (
-	"reflect"
 	"time"
 
 	"github.com/armon/go-metrics"
@@ -200,57 +199,6 @@ type TelemetryConfig struct {
 	PrometheusOpts prometheus.PrometheusOpts
 }
 
-// MergeDefaults copies any non-zero field from defaults into the current
-// config.
-// TODO(kit): We no longer use this function and can probably delete it
-func (c *TelemetryConfig) MergeDefaults(defaults *TelemetryConfig) {
-	if defaults == nil {
-		return
-	}
-	cfgPtrVal := reflect.ValueOf(c)
-	cfgVal := cfgPtrVal.Elem()
-	otherVal := reflect.ValueOf(*defaults)
-	for i := 0; i < cfgVal.NumField(); i++ {
-		f := cfgVal.Field(i)
-		if !f.IsValid() || !f.CanSet() {
-			continue
-		}
-		// See if the current value is a zero-value, if _not_ skip it
-		//
-		// No built in way to check for zero-values for all types so only
-		// implementing this for the types we actually have for now. Test failure
-		// should catch the case where we add new types later.
-		switch f.Kind() {
-		case reflect.Struct:
-			if f.Type() == reflect.TypeOf(prometheus.PrometheusOpts{}) {
-				continue
-			}
-		case reflect.Slice:
-			if !f.IsNil() {
-				continue
-			}
-		case reflect.Int, reflect.Int64: // time.Duration == int64
-			if f.Int() != 0 {
-				continue
-			}
-		case reflect.String:
-			if f.String() != "" {
-				continue
-			}
-		case reflect.Bool:
-			if f.Bool() {
-				continue
-			}
-		default:
-			// Needs implementing, should be caught by tests.
-			continue
-		}
-
-		// It's zero, copy it from defaults
-		f.Set(otherVal.Field(i))
-	}
-}
-
 func statsiteSink(cfg TelemetryConfig, hostname string) (metrics.MetricSink, error) {
 	addr := cfg.StatsiteAddr
 	if addr == "" {
diff --git a/lib/telemetry_test.go b/lib/telemetry_test.go
deleted file mode 100644
index 4ee012f1ec..0000000000
--- a/lib/telemetry_test.go
+++ /dev/null
@@ -1,99 +0,0 @@
-package lib
-
-import (
-	"reflect"
-	"testing"
-	"time"
-
-	"github.com/armon/go-metrics/prometheus"
-
-	"github.com/stretchr/testify/require"
-)
-
-func makeFullTelemetryConfig(t *testing.T) TelemetryConfig {
-	var (
-		promOpts    = prometheus.PrometheusOpts{}
-		strSliceVal = []string{"foo"}
-		strVal      = "foo"
-		intVal      = int64(1 * time.Second)
-	)
-
-	cfg := TelemetryConfig{}
-	cfgP := reflect.ValueOf(&cfg)
-	cfgV := cfgP.Elem()
-	for i := 0; i < cfgV.NumField(); i++ {
-		f := cfgV.Field(i)
-		if !f.IsValid() || !f.CanSet() {
-			continue
-		}
-		// Set non-zero values for all fields. We only implement kinds that exist
-		// now for brevity but will fail the test if a new field type is added since
-		// this is likely not implemented in MergeDefaults either.
-		switch f.Kind() {
-		case reflect.Struct:
-			if f.Type() != reflect.TypeOf(promOpts) {
-				t.Fatalf("unknown struct type in TelemetryConfig: actual %v, expected: %v", f.Type(), reflect.TypeOf(promOpts))
-			}
-			// TODO(kit): This should delve into the fields and set them individually rather than using an empty struct
-			f.Set(reflect.ValueOf(promOpts))
-		case reflect.Slice:
-			if f.Type() != reflect.TypeOf(strSliceVal) {
-				t.Fatalf("unknown slice type in TelemetryConfig." +
-					" You need to update MergeDefaults and this test code.")
-			}
-			f.Set(reflect.ValueOf(strSliceVal))
-		case reflect.Int, reflect.Int64: // time.Duration == int64
-			f.SetInt(intVal)
-		case reflect.String:
-			f.SetString(strVal)
-		case reflect.Bool:
-			f.SetBool(true)
-		default:
-			t.Fatalf("unknown field type in TelemetryConfig" +
-				" You need to update MergeDefaults and this test code.")
-		}
-	}
-	return cfg
-}
-
-func TestTelemetryConfig_MergeDefaults(t *testing.T) {
-	tests := []struct {
-		name     string
-		cfg      TelemetryConfig
-		defaults TelemetryConfig
-		want     TelemetryConfig
-	}{
-		{
-			name: "basic merge",
-			cfg: TelemetryConfig{
-				StatsiteAddr: "stats.it:4321",
-			},
-			defaults: TelemetryConfig{
-				StatsdAddr:   "localhost:5678",
-				StatsiteAddr: "localhost:1234",
-			},
-			want: TelemetryConfig{
-				StatsdAddr:   "localhost:5678",
-				StatsiteAddr: "stats.it:4321",
-			},
-		},
-		{
-			// This test uses reflect to build a TelemetryConfig with every value set
-			// to ensure that we exercise every possible field type. This means that
-			// if new fields are added that are not supported types in the code, this
-			// test should either ensure they work or fail to build the test case and
-			// fail the test.
-			name:     "exhaustive",
-			cfg:      TelemetryConfig{},
-			defaults: makeFullTelemetryConfig(t),
-			want:     makeFullTelemetryConfig(t),
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			c := tt.cfg
-			c.MergeDefaults(&tt.defaults)
-			require.Equal(t, tt.want, c)
-		})
-	}
-}