Implement a server-side config service interface.

luci_config/server/cfgclient/config_test.go

Index: luci_config/server/cfgclient/config_test.go
diff --git a/luci_config/server/cfgclient/config_test.go b/luci_config/server/cfgclient/config_test.go
new file mode 100644
index 0000000000000000000000000000000000000000..c03a7cc1af6237908a65742c9a360e6c4134913f
--- /dev/null
+++ b/luci_config/server/cfgclient/config_test.go
@@ -0,0 +1,222 @@
+// Copyright 2016 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package cfgclient
+
+import (
+	"fmt"
+	"net/url"
+	"testing"
+
+	"github.com/luci/luci-go/common/errors"
+	"github.com/luci/luci-go/luci_config/server/cfgclient/backend"
+
+	"golang.org/x/net/context"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+// testingBackend is a Backend implementation that ignores Authority.
+type testingBackend struct {
+	serviceURL *url.URL
+	err        error
+	items      []*backend.Item
+	url        url.URL
+}
+
+func (tb *testingBackend) ServiceURL(context.Context) url.URL { return *tb.serviceURL }
+
+func (tb *testingBackend) Get(c context.Context, configSet, path string, p backend.Params) (*backend.Item, error) {
+	if err := tb.err; err != nil {
+		return nil, tb.err
+	}
+	if len(tb.items) == 0 {
+		return nil, ErrNoConfig
+	}
+	return tb.cloneItems()[0], nil
+}
+
+func (tb *testingBackend) GetAll(c context.Context, t backend.GetAllTarget, path string, p backend.Params) (
+	[]*backend.Item, error) {
+
+	if err := tb.err; err != nil {
+		return nil, tb.err
+	}
+	return tb.cloneItems(), nil
+}
+
+func (tb *testingBackend) ConfigSetURL(c context.Context, configSet string, p backend.Params) (url.URL, error) {
+	return tb.url, tb.err
+}
+
+func (tb *testingBackend) cloneItems() []*backend.Item {
+	clones := make([]*backend.Item, len(tb.items))
+	for i, it := range tb.items {
+		clone := *it
+		clones[i] = &clone
+	}
+	return clones
+}
+
+type errorMultiResolver struct {
+	getErr func(i int) error
+	out    *[]string
+}
+
+func (er *errorMultiResolver) PrepareMulti(size int) {
+	*er.out = make([]string, size)
+}
+
+func (er *errorMultiResolver) ResolveItemAt(i int, it *backend.Item) error {
+	if err := er.getErr(i); err != nil {
+		return err
+	}
+	(*er.out)[i] = it.Content
+	return nil
+}
+
+func TestConfig(t *testing.T) {
+	t.Parallel()
+
+	Convey(`A testing backend`, t, func() {
+		c := context.Background()
+
+		var err error
+		tb := testingBackend{
+			items: []*backend.Item{
+				{Meta: backend.Meta{"projects/foo", "path", "####", "v1"}, Content: "foo"},
+				{Meta: backend.Meta{"projects/bar", "path", "####", "v1"}, Content: "bar"},
+			},
+		}
+		transformItems := func(fn func(int, *backend.Item)) {
+			for i, itm := range tb.items {
+				fn(i, itm)
+			}
+		}
+		tb.serviceURL, err = url.Parse("http://example.com/config")
+		if err != nil {
+			panic(err)
+		}
+		c = backend.WithBackend(c, &tb)
+
+		Convey(`Can resolve its service URL.`, func() {
+			So(ServiceURL(c), ShouldResemble, *tb.serviceURL)
+		})
+
+		// Caching / type test cases.
+		Convey(`Test byte resolver`, func() {
+			transformItems(func(i int, ci *backend.Item) {
+				ci.Content = string([]byte{byte(i)})
+			})
+
+			Convey(`Single`, func() {
+				var val []byte
+				So(Get(c, AsService, "", "", Bytes(&val), nil), ShouldBeNil)
+				So(val, ShouldResemble, []byte{0})
+			})
+
+			Convey(`Multi`, func() {
+				var (
+					val  [][]byte
+					meta []*Meta
+				)
+				So(Projects(c, AsService, "", BytesSlice(&val), &meta), ShouldBeNil)
+				So(val, ShouldResemble, [][]byte{{0}, {1}})
+				So(meta, ShouldResemble, []*Meta{
+					{"projects/foo", "path", "####", "v1"},
+					{"projects/bar", "path", "####", "v1"},
+				})
+			})
+		})
+
+		Convey(`Test string resolver`, func() {
+			transformItems(func(i int, ci *backend.Item) {
+				ci.Content = fmt.Sprintf("[%d]", i)
+			})
+
+			Convey(`Single`, func() {
+				var val string
+				So(Get(c, AsService, "", "", String(&val), nil), ShouldBeNil)
+				So(val, ShouldEqual, "[0]")
+			})
+
+			Convey(`Multi`, func() {
+				var (
+					val  []string
+					meta []*Meta
+				)
+				So(Projects(c, AsService, "", StringSlice(&val), &meta), ShouldBeNil)
+				So(val, ShouldResemble, []string{"[0]", "[1]"})
+				So(meta, ShouldResemble, []*Meta{
+					{"projects/foo", "path", "####", "v1"},
+					{"projects/bar", "path", "####", "v1"},
+				})
+			})
+		})
+
+		Convey(`Test nil resolver`, func() {
+			transformItems(func(i int, ci *backend.Item) {
+				ci.Content = fmt.Sprintf("[%d]", i)
+			})
+
+			Convey(`Single`, func() {
+				var meta Meta
+				So(Get(c, AsService, "", "", nil, &meta), ShouldBeNil)
+				So(meta, ShouldResemble, Meta{"projects/foo", "path", "####", "v1"})
+			})
+
+			Convey(`Multi`, func() {
+				var meta []*Meta
+				So(Projects(c, AsService, "", nil, &meta), ShouldBeNil)
+				So(meta, ShouldResemble, []*Meta{
+					{"projects/foo", "path", "####", "v1"},
+					{"projects/bar", "path", "####", "v1"},
+				})
+			})
+		})
+
+		Convey(`Projects with some errors returns a MultiError.`, func() {
+			testErr := errors.New("test error")
+			var (
+				val  []string
+				meta []*Meta
+			)
+			er := errorMultiResolver{
+				out: &val,
+				getErr: func(i int) error {
+					if i == 1 {
+						return testErr
+					}
+					return nil
+				},
+			}
+
+			err := Projects(c, AsService, "", &er, &meta)
+
+			// We have a MultiError with an error in position 1.
+			So(err, ShouldResemble, errors.MultiError{nil, testErr})
+
+			// One of our configs should have resolved.
+			So(val, ShouldResemble, []string{"foo", ""})
+
+			// Meta still works.
+			So(meta, ShouldResemble, []*Meta{
+				{"projects/foo", "path", "####", "v1"},
+				{"projects/bar", "path", "####", "v1"},
+			})
+		})
+
+		Convey(`Test ConfigSetURL`, func() {
+			u, err := url.Parse("https://example.com/foo/bar")
+			if err != nil {
+				panic(err)
+			}
+
+			tb.url = *u
+			uv, err := GetConfigSetURL(c, AsService, "")
+			So(err, ShouldBeNil)
+			So(uv, ShouldResemble, url.URL{Scheme: "https", Host: "example.com", Path: "/foo/bar"})
+		})
+	})
+}