Merge pull request #127838 from benluddy/unstructured-nested-number-as-float64

Add NestedNumberAsFloat64 unstructured field accessor.

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/unstructured/helpers.go

@@ -125,6 +125,28 @@ func NestedInt64(obj map[string]interface{}, fields ...string) (int64, bool, err
 	return i, true, nil
 }
 
+// NestedNumberAsFloat64 returns the float64 value of a nested field. If the field's value is a
+// float64, it is returned. If the field's value is an int64 that can be losslessly converted to
+// float64, it will be converted and returned.  Returns false if value is not found and an error if
+// not a float64 or an int64 that can be accurately represented as a float64.
+func NestedNumberAsFloat64(obj map[string]interface{}, fields ...string) (float64, bool, error) {
+	val, found, err := NestedFieldNoCopy(obj, fields...)
+	if !found || err != nil {
+		return 0, found, err
+	}
+	switch x := val.(type) {
+	case int64:
+		if x != int64(float64(x)) {
+			return 0, false, fmt.Errorf("%v accessor error: int64 value %v cannot be losslessly converted to float64", jsonPath(fields), x)
+		}
+		return float64(x), true, nil
+	case float64:
+		return x, true, nil
+	default:
+		return 0, false, fmt.Errorf("%v accessor error: %v is of the type %T, expected float64 or int64", jsonPath(fields), val, val)
+	}
+}
+
 // NestedStringSlice returns a copy of []string value of a nested field.
 // Returns false if value is not found and an error if not a []interface{} or contains non-string items in the slice.
 func NestedStringSlice(obj map[string]interface{}, fields ...string) ([]string, bool, error) {

staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/unstructured/helpers_test.go

@@ -18,6 +18,7 @@ package unstructured
 
 import (
 	"io/ioutil"
+	"math"
 	"sync"
 	"testing"
 
@@ -225,3 +226,74 @@ func TestSetNestedMap(t *testing.T) {
 	assert.Len(t, obj["x"].(map[string]interface{})["z"], 1)
 	assert.Equal(t, "bar", obj["x"].(map[string]interface{})["z"].(map[string]interface{})["b"])
 }
+
+func TestNestedNumberAsFloat64(t *testing.T) {
+	for _, tc := range []struct {
+		name           string
+		obj            map[string]interface{}
+		path           []string
+		wantFloat64    float64
+		wantBool       bool
+		wantErrMessage string
+	}{
+		{
+			name:           "not found",
+			obj:            nil,
+			path:           []string{"missing"},
+			wantFloat64:    0,
+			wantBool:       false,
+			wantErrMessage: "",
+		},
+		{
+			name:           "found float64",
+			obj:            map[string]interface{}{"value": float64(42)},
+			path:           []string{"value"},
+			wantFloat64:    42,
+			wantBool:       true,
+			wantErrMessage: "",
+		},
+		{
+			name:           "found unexpected type bool",
+			obj:            map[string]interface{}{"value": true},
+			path:           []string{"value"},
+			wantFloat64:    0,
+			wantBool:       false,
+			wantErrMessage: ".value accessor error: true is of the type bool, expected float64 or int64",
+		},
+		{
+			name:           "found int64",
+			obj:            map[string]interface{}{"value": int64(42)},
+			path:           []string{"value"},
+			wantFloat64:    42,
+			wantBool:       true,
+			wantErrMessage: "",
+		},
+		{
+			name:           "found int64 not representable as float64",
+			obj:            map[string]interface{}{"value": int64(math.MaxInt64)},
+			path:           []string{"value"},
+			wantFloat64:    0,
+			wantBool:       false,
+			wantErrMessage: ".value accessor error: int64 value 9223372036854775807 cannot be losslessly converted to float64",
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			gotFloat64, gotBool, gotErr := NestedNumberAsFloat64(tc.obj, tc.path...)
+			if gotFloat64 != tc.wantFloat64 {
+				t.Errorf("got %v, wanted %v", gotFloat64, tc.wantFloat64)
+			}
+			if gotBool != tc.wantBool {
+				t.Errorf("got %t, wanted %t", gotBool, tc.wantBool)
+			}
+			if tc.wantErrMessage != "" {
+				if gotErr == nil {
+					t.Errorf("got nil error, wanted %s", tc.wantErrMessage)
+				} else if gotErrMessage := gotErr.Error(); gotErrMessage != tc.wantErrMessage {
+					t.Errorf("wanted error %q, got: %v", gotErrMessage, tc.wantErrMessage)
+				}
+			} else if gotErr != nil {
+				t.Errorf("wanted nil error, got %v", gotErr)
+			}
+		})
+	}
+}