Added inverse functions for the ptr package (#2172)

* Added inverse functions for the ptr package

* PR Comments

* Linter fix

ptr/value.go

@@ -0,0 +1,91 @@
+/*
+Copyright 2021 The Knative 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 ptr
+
+import "time"
+
+// Int32Value is a helper for turning pointers to integers into values for use
+// in API types that want int32.
+func Int32Value(i *int32) int32 {
+	if i == nil {
+		return 0
+	}
+	return *i
+}
+
+// Int64Value is a helper for turning pointers to integers into values for use
+// in API types that want int64.
+func Int64Value(i *int64) int64 {
+	if i == nil {
+		return 0
+	}
+	return *i
+}
+
+// Float32Value is a helper for turning pointers to floats into values for use
+// in API types that want float32.
+func Float32Value(f *float32) float32 {
+	if f == nil {
+		return 0
+	}
+	return *f
+}
+
+// Float64Value is a helper for turning pointers to floats into values for use
+// in API types that want float64.
+func Float64Value(f *float64) float64 {
+	if f == nil {
+		return 0
+	}
+	return *f
+}
+
+// BoolValue is a helper for turning pointers to bools into values for use in
+// API types that want bool.
+func BoolValue(b *bool) bool {
+	if b == nil {
+		return false
+	}
+	return *b
+}
+
+// StringValue is a helper for turning pointers to strings into values for use
+// in API types that want string.
+func StringValue(s *string) string {
+	if s == nil {
+		return ""
+	}
+	return *s
+}
+
+// DurationValue is a helper for turning *time.Duration into values for use in
+// API types that want time.Duration.
+func DurationValue(t *time.Duration) time.Duration {
+	if t == nil {
+		return 0
+	}
+	return *t
+}
+
+// TimeValue is a helper for turning *time.Time into values for use in API
+// types that want API types that want time.Time.
+func TimeValue(t *time.Time) time.Time {
+	if t == nil {
+		return time.Time{}
+	}
+	return *t
+}

ptr/value_test.go

@@ -0,0 +1,148 @@
+/*
+Copyright 2021 The Knative 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 ptr
+
+import (
+	"testing"
+	"time"
+)
+
+func TestInt32Value(t *testing.T) {
+	want := int32(55)
+	gotValue := Int32Value(&want)
+	if want != gotValue {
+		t.Errorf("Int32() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestInt32Value_Nil(t *testing.T) {
+	want := int32(0)
+	gotValue := Int32Value(nil)
+	if want != gotValue {
+		t.Errorf("Int32() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestInt64Value(t *testing.T) {
+	want := int64(55)
+	gotValue := Int64Value(&want)
+	if want != gotValue {
+		t.Errorf("Int64() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestInt64Value_Nil(t *testing.T) {
+	want := int64(0)
+	gotValue := Int64Value(nil)
+	if want != gotValue {
+		t.Errorf("Int64() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestFloat32Value(t *testing.T) {
+	want := float32(1.25)
+	gotValue := Float32Value(&want)
+	if want != gotValue {
+		t.Errorf("Float32() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestFloat32Value_Nil(t *testing.T) {
+	want := float32(0)
+	gotValue := Float32Value(nil)
+	if want != gotValue {
+		t.Errorf("Float32() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestFloat64Value(t *testing.T) {
+	want := 1.25
+	gotValue := Float64Value(&want)
+	if want != gotValue {
+		t.Errorf("Float64() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestFloat64Value_Nil(t *testing.T) {
+	want := float64(0)
+	gotValue := Float64Value(nil)
+	if want != gotValue {
+		t.Errorf("Float64() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestBoolValue(t *testing.T) {
+	want := true
+	gotValue := BoolValue(&want)
+	if want != gotValue {
+		t.Errorf("Bool() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestBoolValue_Nil(t *testing.T) {
+	want := false
+	gotValue := BoolValue(nil)
+	if want != gotValue {
+		t.Errorf("Bool() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestStringValue(t *testing.T) {
+	want := "should be a pointer"
+	gotValue := StringValue(&want)
+	if want != gotValue {
+		t.Errorf("String() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestStringValue_Nil(t *testing.T) {
+	want := ""
+	gotValue := StringValue(nil)
+	if want != gotValue {
+		t.Errorf("String() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestTimeValue(t *testing.T) {
+	want := time.Now().Add(time.Minute)
+	if got, want := TimeValue(&want), want; got != want {
+		t.Errorf("got = %v, want: %v", got, want)
+	}
+}
+
+func TestTimeValue_Nil(t *testing.T) {
+	want := time.Time{}
+	if got, want := TimeValue(nil), want; got != want {
+		t.Errorf("got = %v, want: %v", got, want)
+	}
+}
+
+func TestDurationValue(t *testing.T) {
+	want := 42 * time.Second
+	gotValue := DurationValue(&want)
+	if want != gotValue {
+		t.Errorf("Duration() = &%v, wanted %v", gotValue, want)
+	}
+}
+
+func TestDurationValue_Nil(t *testing.T) {
+	want := time.Duration(0)
+	gotValue := DurationValue(nil)
+	if want != gotValue {
+		t.Errorf("Duration() = &%v, wanted %v", gotValue, want)
+	}
+}