test: descending array cursor should include end time

cmd/influxd/launcher/query_test.go

@@ -759,6 +759,25 @@ func TestQueryPushDowns(t *testing.T) {
 		op    string
 		want  string
 	}{
+		{
+			name: "range last single point start time",
+			data: []string{
+				"m,tag=a f=1i 1",
+			},
+			query: `
+from(bucket: v.bucket)
+	|> range(start: 1970-01-01T00:00:00.000000001Z, stop: 1970-01-01T01:00:00Z)
+	|> last()
+`,
+			op: "readWindow(last)",
+			want: `
+#datatype,string,long,dateTime:RFC3339,dateTime:RFC3339,dateTime:RFC3339,long,string,string,string
+#group,false,false,true,true,false,false,true,true,true
+#default,_result,,,,,,,,
+,result,table,_start,_stop,_time,_value,_field,_measurement,tag
+,,0,1970-01-01T00:00:00.000000001Z,1970-01-01T01:00:00Z,1970-01-01T00:00:00.000000001Z,1,f,m,a
+`,
+		},
 		{
 			name: "window last",
 			data: []string{

tsdb/tsm1/array_cursor_test.go

@@ -70,6 +70,67 @@ func newFiles(dir string, values ...keyValues) ([]string, error) {
 	return files, nil
 }
 
+func TestDescendingCursor_SinglePointStartTime(t *testing.T) {
+	t.Run("cache", func(t *testing.T) {
+		dir := MustTempDir()
+		defer os.RemoveAll(dir)
+		fs := NewFileStore(dir)
+
+		const START, END = 10, 1
+		kc := fs.KeyCursor(context.Background(), []byte("m,_field=v#!~#v"), START, false)
+		defer kc.Close()
+		cur := newIntegerArrayDescendingCursor()
+		// Include a cached value with timestamp equal to END
+		cur.reset(START, END, Values{NewIntegerValue(1, 1)}, kc)
+
+		var got []int64
+		ar := cur.Next()
+		for ar.Len() > 0 {
+			got = append(got, ar.Timestamps...)
+			ar = cur.Next()
+		}
+
+		if exp := []int64{1}; !cmp.Equal(got, exp) {
+			t.Errorf("unexpected values; -got/+exp\n%s", cmp.Diff(got, exp))
+		}
+	})
+	t.Run("tsm", func(t *testing.T) {
+		dir := MustTempDir()
+		defer os.RemoveAll(dir)
+		fs := NewFileStore(dir)
+
+		const START, END = 10, 1
+
+		data := []keyValues{
+			// Write a single data point with timestamp equal to END
+			{"m,_field=v#!~#v", []Value{NewIntegerValue(1, 1)}},
+		}
+
+		files, err := newFiles(dir, data...)
+		if err != nil {
+			t.Fatalf("unexpected error creating files: %v", err)
+		}
+
+		_ = fs.Replace(nil, files)
+
+		kc := fs.KeyCursor(context.Background(), []byte("m,_field=v#!~#v"), START, false)
+		defer kc.Close()
+		cur := newIntegerArrayDescendingCursor()
+		cur.reset(START, END, nil, kc)
+
+		var got []int64
+		ar := cur.Next()
+		for ar.Len() > 0 {
+			got = append(got, ar.Timestamps...)
+			ar = cur.Next()
+		}
+
+		if exp := []int64{1}; !cmp.Equal(got, exp) {
+			t.Errorf("unexpected values; -got/+exp\n%s", cmp.Diff(got, exp))
+		}
+	})
+}
+
 func TestFileStore_DuplicatePoints(t *testing.T) {
 	dir := MustTempDir()
 	defer os.RemoveAll(dir)