Bound remote control object reads

internal/artifacts/current_state_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"strings"
 	"testing"
 	"time"
@@ -119,6 +120,50 @@ func TestLoadCurrentStateReadsCoherentLegacyPair(t *testing.T) {
 	if state.Commit != nil || state.Pointer != nil {
 		t.Fatalf("legacy current state unexpectedly includes immutable commit data: %#v", state)
 	}
+	if len(store.Downloads) != 0 {
+		t.Fatalf("legacy current-state downloads = %#v, want direct bounded reads", store.Downloads)
+	}
+	wantReads := []string{state.CurrentRunIDKey, state.CurrentManifestKey}
+	if len(store.Reads) != len(wantReads) {
+		t.Fatalf("legacy current-state reads = %#v, want %q", store.Reads, wantReads)
+	}
+	for index, want := range wantReads {
+		if store.Reads[index].Key != want {
+			t.Fatalf("legacy current-state read %d = %q, want %q", index, store.Reads[index].Key, want)
+		}
+	}
+}
+
+func TestCurrentStateControlObjectLimitsAcceptExactAndRejectLimitPlusOne(t *testing.T) {
+	tests := []struct {
+		name     string
+		category string
+		key      string
+		limit    int64
+	}{
+		{name: "commit pointer", category: "current commit pointer", key: "current/commit-pointer.json", limit: MaxCurrentCommitPointerBytes},
+		{name: "commit manifest", category: "remote commit manifest", key: "runs/run/commit.json", limit: MaxRemoteCommitManifestBytes},
+		{name: "session manifest", category: "committed session manifest", key: "runs/run/session-manifest.json", limit: MaxRemoteSessionManifestBytes},
+		{name: "legacy run pointer", category: "legacy current run pointer", key: "current/run_id.txt", limit: MaxLegacyCurrentRunPointerBytes},
+		{name: "legacy manifest", category: "legacy current manifest", key: "current/manifest.json", limit: MaxLegacyCurrentManifestBytes},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			store := &storage.FakeBackend{}
+			exact := strings.Repeat("x", int(test.limit))
+			store.SeedObject(storage.FakeObject{Key: test.key, Data: []byte(exact)})
+			_, data, err := readCurrentStateControlObject(context.Background(), store, test.key, test.category, test.limit)
+			if err != nil || string(data) != exact {
+				t.Fatalf("exact-limit read data length=%d error=%v", len(data), err)
+			}
+
+			store.SeedObject(storage.FakeObject{Key: test.key, Data: []byte(exact + "x")})
+			_, _, err = readCurrentStateControlObject(context.Background(), store, test.key, test.category, test.limit)
+			if err == nil || !strings.Contains(err.Error(), test.category) || !strings.Contains(err.Error(), test.key) || !strings.Contains(err.Error(), fmt.Sprint(test.limit)) {
+				t.Fatalf("limit-plus-one error = %v, want category, key, and limit", err)
+			}
+		})
+	}
 }
 
 func TestLoadCurrentStateRejectsTornLegacyPair(t *testing.T) {