internal/credential: add pagination options

The new options are used in future commits for paginating list results.

internal/credential/options.go

@@ -4,6 +4,11 @@
 package credential
 
 import (
+	"errors"
+
+	"github.com/hashicorp/boundary/internal/db"
+	"github.com/hashicorp/boundary/internal/pagination"
+	"github.com/hashicorp/boundary/internal/util"
 	"github.com/hashicorp/boundary/internal/util/template"
 )
 
@@ -26,7 +31,11 @@ type Option func(*options) error
 
 // options = how options are represented
 type options struct {
-	WithTemplateData template.Data
+	WithTemplateData       template.Data
+	WithReader             db.Reader
+	WithWriter             db.Writer
+	WithLimit              int
+	WithStartPageAfterItem pagination.Item
 }
 
 func getDefaultOptions() *options {
@@ -40,3 +49,41 @@ func WithTemplateData(with template.Data) Option {
 		return nil
 	}
 }
+
+// WithReaderWriter allows the caller to pass an inflight transaction to be used
+// for all database operations. If WithReaderWriter(...) is used, then the
+// caller is responsible for managing the transaction.
+func WithReaderWriter(r db.Reader, w db.Writer) Option {
+	return func(o *options) error {
+		switch {
+		case util.IsNil(r):
+			return errors.New("nil reader")
+		case util.IsNil(w):
+			return errors.New("nil writer")
+		}
+		o.WithReader = r
+		o.WithWriter = w
+		return nil
+	}
+}
+
+// WithLimit provides an option to provide a limit.
+// If WithLimit == 0, then default limits are used for results.
+func WithLimit(l int) Option {
+	return func(o *options) error {
+		if l < 0 {
+			return errors.New("limit must be at least 0")
+		}
+		o.WithLimit = l
+		return nil
+	}
+}
+
+// WithStartPageAfterItem is used to paginate over the results.
+// The next page will start after the provided item.
+func WithStartPageAfterItem(item pagination.Item) Option {
+	return func(o *options) error {
+		o.WithStartPageAfterItem = item
+		return nil
+	}
+}

internal/credential/options_test.go

@@ -5,20 +5,118 @@ package credential
 
 import (
 	"testing"
+	"time"
 
+	"github.com/hashicorp/boundary/internal/db"
+	"github.com/hashicorp/boundary/internal/db/timestamp"
+	"github.com/hashicorp/boundary/internal/pagination"
 	"github.com/hashicorp/boundary/internal/util"
 	"github.com/hashicorp/boundary/internal/util/template"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
+type fakeWriter struct {
+	db.Writer
+}
+
+type fakeReader struct {
+	db.Reader
+}
+
+type fakeItem struct {
+	pagination.Item
+	publicId   string
+	updateTime time.Time
+	createTime time.Time
+}
+
+func (p *fakeItem) GetPublicId() string {
+	return p.publicId
+}
+
+func (p *fakeItem) GetUpdateTime() *timestamp.Timestamp {
+	return timestamp.New(p.updateTime)
+}
+
+func (p *fakeItem) GetCreateTime() *timestamp.Timestamp {
+	return timestamp.New(p.createTime)
+}
+
 func Test_GetOpts(t *testing.T) {
 	t.Parallel()
 	t.Run("WithTemplateData", func(t *testing.T) {
+		t.Parallel()
 		opts := getDefaultOptions()
 		assert.Empty(t, opts.WithTemplateData)
 		opts, err := GetOpts(WithTemplateData(template.Data{User: template.User{Id: util.Pointer("foo")}}))
 		require.NoError(t, err)
 		assert.Equal(t, "foo", *opts.WithTemplateData.User.Id)
 	})
+	t.Run("WithLimit", func(t *testing.T) {
+		t.Parallel()
+		t.Run("success", func(t *testing.T) {
+			t.Parallel()
+			opts := getDefaultOptions()
+			assert.Empty(t, opts.WithLimit)
+			opts, err := GetOpts(WithLimit(1))
+			require.NoError(t, err)
+			assert.Equal(t, 1, opts.WithLimit)
+		})
+		t.Run("negative limit", func(t *testing.T) {
+			t.Parallel()
+			opts := getDefaultOptions()
+			assert.Empty(t, opts.WithLimit)
+			_, err := GetOpts(WithLimit(-1))
+			require.Error(t, err)
+		})
+	})
+	t.Run("WithReaderWriter", func(t *testing.T) {
+		t.Parallel()
+		t.Run("success", func(t *testing.T) {
+			t.Parallel()
+			opts := getDefaultOptions()
+			assert.Empty(t, opts.WithReader)
+			assert.Empty(t, opts.WithWriter)
+			r, w := &fakeReader{}, &fakeWriter{}
+			opts, err := GetOpts(WithReaderWriter(r, w))
+			require.NoError(t, err)
+			assert.Equal(t, r, opts.WithReader)
+			assert.Equal(t, w, opts.WithWriter)
+		})
+		t.Run("nil reader", func(t *testing.T) {
+			t.Parallel()
+			w := &fakeWriter{}
+			_, err := GetOpts(WithReaderWriter(nil, w))
+			require.Error(t, err)
+		})
+		t.Run("nil interface reader", func(t *testing.T) {
+			t.Parallel()
+			w := &fakeWriter{}
+			_, err := GetOpts(WithReaderWriter((*fakeReader)(nil), w))
+			require.Error(t, err)
+		})
+		t.Run("nil writer", func(t *testing.T) {
+			t.Parallel()
+			r := &fakeReader{}
+			_, err := GetOpts(WithReaderWriter(r, nil))
+			require.Error(t, err)
+		})
+		t.Run("nil interface writer", func(t *testing.T) {
+			t.Parallel()
+			r := &fakeReader{}
+			_, err := GetOpts(WithReaderWriter(r, (*fakeWriter)(nil)))
+			require.Error(t, err)
+		})
+	})
+	t.Run("WithStartPageAfterItem", func(t *testing.T) {
+		assert := assert.New(t)
+		updateTime := time.Now()
+		createTime := time.Now()
+		opts, err := GetOpts(WithStartPageAfterItem(&fakeItem{nil, "s_1", updateTime, createTime}))
+		require.NoError(t, err)
+		assert.Equal(opts.WithStartPageAfterItem.GetPublicId(), "s_1")
+		assert.Equal(opts.WithStartPageAfterItem.GetUpdateTime(), timestamp.New(updateTime))
+		assert.Equal(opts.WithStartPageAfterItem.GetCreateTime(), timestamp.New(createTime))
+	})
 }