docstore: implement update queries (#2045)

internal/docstore/docstore.go

@@ -302,29 +302,40 @@ func (a *Action) toDriverAction() (*driver.Action, error) {
 		}
 	}
 	if a.mods != nil {
-		// Convert mods from a map to a slice of (fieldPath, value) pairs.
-		// The map is easier for users to write, but the slice is easier
-		// to process.
-		// TODO(jba): check for prefix
-		// Sort keys so tests are deterministic.
-		var keys []string
-		for k := range a.mods {
-			keys = append(keys, string(k))
-		}
-		sort.Strings(keys)
-		for _, k := range keys {
-			k := FieldPath(k)
-			v := a.mods[k]
-			fp, err := parseFieldPath(k)
-			if err != nil {
-				return nil, err
-			}
-			d.Mods = append(d.Mods, driver.Mod{FieldPath: fp, Value: v})
+		d.Mods, err = toDriverMods(a.mods)
+		if err != nil {
+			return nil, err
 		}
 	}
 	return d, nil
 }
 
+func toDriverMods(mods Mods) ([]driver.Mod, error) {
+	// Convert mods from a map to a slice of (fieldPath, value) pairs.
+	// The map is easier for users to write, but the slice is easier
+	// to process.
+	// TODO(jba): check for prefix
+
+	// Sort keys so tests are deterministic.
+	var keys []string
+	for k := range mods {
+		keys = append(keys, string(k))
+	}
+	sort.Strings(keys)
+
+	dmods := make([]driver.Mod, len(keys))
+	for i, k := range keys {
+		k := FieldPath(k)
+		v := mods[k]
+		fp, err := parseFieldPath(k)
+		if err != nil {
+			return nil, err
+		}
+		dmods[i] = driver.Mod{FieldPath: fp, Value: v}
+	}
+	return dmods, nil
+}
+
 // Create is a convenience for building and running a single-element action list.
 // See ActionList.Create.
 func (c *Collection) Create(ctx context.Context, doc Document) error {

internal/docstore/driver/driver.go

@@ -47,6 +47,9 @@ type Collection interface {
 	// RunDeleteQuery deletes every document matched by the query.
 	RunDeleteQuery(context.Context, *Query) error
 
+	// RunUpdateQuery updates every document matched by the query.
+	RunUpdateQuery(context.Context, *Query, []Mod) error
+
 	// QueryPlan returns the plan for the query.
 	QueryPlan(*Query) (string, error)
 

internal/docstore/drivertest/drivertest.go

@@ -166,6 +166,7 @@ func RunConformanceTests(t *testing.T, newHarness HarnessMaker, ct CodecTester,
 
 	t.Run("GetQuery", func(t *testing.T) { withTwoKeyCollection(t, newHarness, testGetQuery) })
 	t.Run("DeleteQuery", func(t *testing.T) { withTwoKeyCollection(t, newHarness, testDeleteQuery) })
+	t.Run("UpdateQuery", func(t *testing.T) { withTwoKeyCollection(t, newHarness, testUpdateQuery) })
 
 	asTests = append(asTests, verifyAsFailsOnNil{})
 	t.Run("As", func(t *testing.T) {
@@ -401,7 +402,6 @@ func testUpdate(t *testing.T, coll *ds.Collection) {
 	if err := coll.Put(ctx, doc); err != nil {
 		t.Fatal(err)
 	}
-
 	got := docmap{KeyField: doc[KeyField]}
 	errs := coll.Actions().Update(doc, ds.Mods{
 		"a": "X",
@@ -880,12 +880,7 @@ func testGetQuery(t *testing.T, coll *ds.Collection) {
 			for _, g := range got {
 				g.DocstoreRevision = nil
 			}
-			var want []*HighScore
-			for _, d := range queryDocuments {
-				if tc.want(d) {
-					want = append(want, d)
-				}
-			}
+			want := filterHighScores(queryDocuments, tc.want)
 			_, err := tc.q.Plan()
 			if err != nil {
 				t.Fatal(err)
@@ -960,12 +955,7 @@ func testDeleteQuery(t *testing.T, coll *ds.Collection) {
 			for _, g := range got {
 				g.DocstoreRevision = nil
 			}
-			var want []*HighScore
-			for _, d := range prevWant {
-				if tc.want(d) {
-					want = append(want, d)
-				}
-			}
+			want := filterHighScores(prevWant, tc.want)
 			prevWant = want
 			diff := cmp.Diff(got, want, cmpopts.SortSlices(func(h1, h2 *HighScore) bool {
 				return h1.Game+"|"+h1.Player < h2.Game+"|"+h2.Player
@@ -983,6 +973,51 @@ func testDeleteQuery(t *testing.T, coll *ds.Collection) {
 	}
 }
 
+func testUpdateQuery(t *testing.T, coll *ds.Collection) {
+	ctx := context.Background()
+	if err := coll.Query().Update(ctx, nil); gcerrors.Code(err) == gcerrors.Unimplemented {
+		t.Skip("update queries not yet implemented")
+	}
+
+	cleanUpTable(t, newHighScore, coll)
+
+	addQueryDocuments(t, coll)
+
+	err := coll.Query().Where("Player", "=", "fran").Update(ctx, docstore.Mods{"Score": 13, "Time": nil})
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := mustCollectHighScores(ctx, t, coll.Query().Get(ctx))
+	for _, g := range got {
+		g.DocstoreRevision = nil
+	}
+
+	want := filterHighScores(queryDocuments, func(h *HighScore) bool {
+		if h.Player == "fran" {
+			h.Score = 13
+			h.Time = time.Time{}
+		}
+		return true
+	})
+	diff := cmp.Diff(got, want, cmpopts.SortSlices(func(h1, h2 *HighScore) bool {
+		return h1.Game+"|"+h1.Player < h2.Game+"|"+h2.Player
+	}))
+	if diff != "" {
+		t.Error(diff)
+	}
+}
+
+func filterHighScores(hs []*HighScore, f func(*HighScore) bool) []*HighScore {
+	var res []*HighScore
+	for _, h := range hs {
+		c := *h // Copy in case f modifies its argument.
+		if f(&c) {
+			res = append(res, &c)
+		}
+	}
+	return res
+}
+
 // cleanUpTable delete all documents from this collection after test.
 func cleanUpTable(t *testing.T, create func() interface{}, coll *docstore.Collection) {
 	if err := coll.Query().Delete(context.Background()); err != nil {

internal/docstore/dynamodocstore/query.go

@@ -24,6 +24,7 @@ import (
 	"github.com/aws/aws-sdk-go/service/dynamodb/expression"
 	"gocloud.dev/internal/docstore"
 	"gocloud.dev/internal/docstore/driver"
+	"gocloud.dev/internal/gcerr"
 )
 
 // TODO: support parallel scans (http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Scan.html#Scan.ParallelScan)
@@ -494,3 +495,7 @@ func (c *collection) RunDeleteQuery(ctx context.Context, q *driver.Query) error
 	}
 	return docstore.ActionListError(alerr)
 }
+
+func (c *collection) RunUpdateQuery(ctx context.Context, q *driver.Query, mods []driver.Mod) error {
+	return gcerr.Newf(gcerr.Unimplemented, nil, "not implemented")
+}