Add custom classes to represent Google Well Known Types

common/types/duration/duration.go

@@ -0,0 +1,67 @@
+package duration
+
+import (
+	"net/url"
+	"strings"
+	"time"
+
+	"google.golang.org/protobuf/encoding/protojson"
+	"google.golang.org/protobuf/types/known/durationpb"
+)
+
+// Duration is a wrapper for durationpb.Duration to provide custom marshaling
+// for JSON and URL query strings.
+//
+// It embeds durationpb.Duration and exposes the .AsDuration() method to
+// easily convert to time.Duration.
+//
+// Example:
+//
+//	customDur := durationpb.New(30 * time.Second)
+//	goDur := customDur.AsDuration()
+type Duration struct {
+	internal *durationpb.Duration
+}
+
+// New creates a custom Duration from a standard time.Duration.
+func New(d time.Duration) *Duration {
+	return &Duration{internal: durationpb.New(d)}
+}
+
+// AsDuration returns the underlying time.Duration value.
+func (x *Duration) AsDuration() time.Duration {
+	if x == nil {
+		return 0
+	}
+	return x.internal.AsDuration()
+}
+
+// MarshalJSON implements the [json.Marshaler] interface
+// by marshalling the duration as a protobuf Duration.
+func (d Duration) MarshalJSON() ([]byte, error) {
+	return protojson.Marshal(d.internal)
+}
+
+// EncodeValues implements the [query.Encoder] interface by encoding the
+// duration as a string, like "3.3s".
+func (d Duration) EncodeValues(key string, v *url.Values) error {
+	res, err := protojson.Marshal(d.internal)
+	if err != nil {
+		return err
+	}
+	// remove the quotes from the string
+	queryValue := strings.Trim(string(res), "\"")
+	v.Set(key, queryValue)
+	return nil
+}
+
+// UnmarshalJSON implements the [json.Unmarshaler] interface. It can parse a
+// duration from the protobuf Duration.
+func (d *Duration) UnmarshalJSON(b []byte) error {
+	var pb durationpb.Duration
+	if err := protojson.Unmarshal(b, &pb); err != nil {
+		return err
+	}
+	*d = *New(pb.AsDuration())
+	return nil
+}

common/types/duration/duration_test.go

@@ -0,0 +1,254 @@
+package duration
+
+import (
+	"encoding/json"
+	"net/url"
+	"testing"
+	"time"
+)
+
+func TestAsDuration(t *testing.T) {
+	d := time.Second * 5
+	dur := New(d)
+	result := dur.AsDuration()
+	if result != d {
+		t.Errorf("AsDuration() = %v, want %v", result, d)
+	}
+}
+
+func TestDuration_MarshalJSON(t *testing.T) {
+	tests := []struct {
+		name     string
+		duration Duration
+		expected string
+		wantErr  bool
+	}{
+		{
+			name:     "zero duration",
+			duration: *New(0),
+			expected: "0s",
+		},
+		{
+			name:     "positive duration",
+			duration: *New(5 * time.Second),
+			expected: "5s",
+		},
+		{
+			name:     "negative duration",
+			duration: *New(-2 * time.Minute),
+			expected: "-120s",
+		},
+		{
+			name:     "negative duration with fractional seconds",
+			duration: *New(-2*time.Minute + 100*time.Millisecond),
+			expected: "-119.900s",
+		},
+		{
+			name:     "fractional seconds",
+			duration: *New(1500 * time.Millisecond),
+			expected: "1.500s",
+		},
+		{
+			name:     "large duration",
+			duration: *New(9223372036*time.Second + 854775000*time.Nanosecond),
+			expected: "9223372036.854775s",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := tt.duration.MarshalJSON()
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Duration.MarshalJSON() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if string(result) != `"`+tt.expected+`"` {
+				t.Errorf("Duration.MarshalJSON() = %v, want %v", string(result), `"`+tt.expected+`"`)
+			}
+		})
+	}
+}
+
+func TestDuration_UnmarshalJSON(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		want    Duration
+		wantErr bool
+	}{
+		{
+			name:    "zero duration",
+			input:   `"0s"`,
+			want:    *New(0),
+			wantErr: false,
+		},
+		{
+			name:    "positive duration",
+			input:   `"5s"`,
+			want:    *New(5 * time.Second),
+			wantErr: false,
+		},
+		{
+			name:    "negative duration",
+			input:   `"-2s"`,
+			want:    *New(-2 * time.Second),
+			wantErr: false,
+		},
+		{
+			name:    "negative duration with fractional seconds",
+			input:   `"-2.1s"`,
+			want:    *New(-2*time.Second - 100*time.Millisecond),
+			wantErr: false,
+		},
+		{
+			name:    "fractional seconds",
+			input:   `"1.5s"`,
+			want:    *New(1500 * time.Millisecond),
+			wantErr: false,
+		},
+		{
+			name:    "large duration",
+			input:   `"9223372036.854775000s"`,
+			want:    *New(9223372036*time.Second + 854775000*time.Nanosecond),
+			wantErr: false,
+		},
+		{
+			name:    "invalid duration format",
+			input:   `"invalid"`,
+			want:    *New(0),
+			wantErr: true,
+		},
+		{
+			name:    "empty string",
+			input:   `""`,
+			want:    *New(0),
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var d Duration
+			err := d.UnmarshalJSON([]byte(tt.input))
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Duration.UnmarshalJSON() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !tt.wantErr {
+				// We cannot compare Proto messages directly, so we compare the underlying time.Duration
+				if d.AsDuration() != tt.want.AsDuration() {
+					t.Errorf("Duration.UnmarshalJSON() = %v, want %v", d.AsDuration(), tt.want.AsDuration())
+				}
+			}
+
+		})
+	}
+}
+
+func TestDuration_EncodeValues(t *testing.T) {
+	tests := []struct {
+		name     string
+		duration Duration
+		key      string
+		expected string
+	}{
+		{
+			name:     "zero duration",
+			duration: *New(0),
+			key:      "duration",
+			expected: "0s",
+		},
+		{
+			name:     "positive duration",
+			duration: *New(5 * time.Second),
+			key:      "timeout",
+			expected: "5s",
+		},
+		{
+			name:     "negative duration",
+			duration: *New(-2 * time.Minute),
+			key:      "delay",
+			expected: "-120s",
+		},
+		{
+			name:     "fractional seconds",
+			duration: *New(1500 * time.Millisecond),
+			key:      "interval",
+			expected: "1.500s",
+		},
+		{
+			name:     "large duration",
+			duration: *New(24 * time.Hour),
+			key:      "period",
+			expected: "86400s",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			values := url.Values{}
+			err := tt.duration.EncodeValues(tt.key, &values)
+			if err != nil {
+				t.Errorf("Duration.EncodeValues() error = %v", err)
+				return
+			}
+			result := values.Get(tt.key)
+			if result != tt.expected {
+				t.Errorf("Duration.EncodeValues() = %v, want %v", result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestDuration_JSONRoundTrip(t *testing.T) {
+	tests := []struct {
+		name     string
+		duration Duration
+	}{
+		{
+			name:     "zero duration",
+			duration: *New(0),
+		},
+		{
+			name:     "positive duration",
+			duration: *New(5 * time.Second),
+		},
+		{
+			name:     "negative duration",
+			duration: *New(-2 * time.Minute),
+		},
+		{
+			name:     "fractional seconds",
+			duration: *New(1500 * time.Millisecond),
+		},
+		{
+			name:     "complex duration",
+			duration: *New(1*time.Hour + 2*time.Minute + 3*time.Second),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Marshal to JSON
+			jsonData, err := json.Marshal(tt.duration)
+			if err != nil {
+				t.Errorf("json.Marshal() error = %v", err)
+				return
+			}
+
+			// Unmarshal from JSON
+			var result Duration
+			err = json.Unmarshal(jsonData, &result)
+			if err != nil {
+				t.Errorf("json.Unmarshal() error = %v", err)
+				return
+			}
+
+			// Check that the round trip preserved the value
+			if result.AsDuration() != tt.duration.AsDuration() {
+				t.Errorf("Duration.UnmarshalJSON() = %v, want %v", result.AsDuration(), tt.duration.AsDuration())
+			}
+
+		})
+	}
+}

common/types/fieldmask/fieldmask.go

@@ -0,0 +1,63 @@
+package fieldmask
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+// FieldMask represents a field mask as defined in Google's Well Known Types.
+// It is used to specify which fields of a resource should be included or excluded
+// in a request or response.
+type FieldMask struct {
+	Paths []string
+}
+
+// New creates a FieldMask from a slice of field paths.
+func New(paths []string) *FieldMask {
+	return &FieldMask{Paths: paths}
+}
+
+// MarshalJSON implements the [json.Marshaler] interface by formatting the
+// field mask as a string according to Google Well Known Type
+func (f FieldMask) MarshalJSON() ([]byte, error) {
+	return json.Marshal(strings.Join(f.Paths, ","))
+}
+
+// UnmarshalJSON implements the [json.Unmarshaler] interface by parsing the
+// field mask from a string according to Google Well Known Type
+func (f *FieldMask) UnmarshalJSON(data []byte) error {
+	if f == nil {
+		return fmt.Errorf("json.Unmarshal on nil pointer")
+	}
+
+	var s string
+	if err := json.Unmarshal(data, &s); err != nil {
+		return err
+	}
+
+	if s != "" {
+		f.Paths = strings.Split(s, ",")
+	} else {
+		f.Paths = []string{}
+	}
+
+	return nil
+}
+
+// EncodeValues implements the [query.Encoder] interface by encoding the
+// field mask as a string, like "a,b,c".
+// If the FieldMask is nil or empty, it returns nil.
+// If the url.Values is nil, it returns an error.
+func (f *FieldMask) EncodeValues(key string, v *url.Values) error {
+	if f == nil || len(f.Paths) == 0 {
+		return nil
+	}
+	if v == nil {
+		return fmt.Errorf("url.Values is nil")
+	}
+
+	v.Set(key, strings.Join(f.Paths, ","))
+	return nil
+}