Refine comments

Signed-off-by: JaySon-Huang <[email protected]>

pkg/ddl/placement/bundle.go

@@ -314,8 +314,8 @@ func (b *Bundle) String() string {
 
 // Tidy will post optimize Rules, trying to generate rules that suits PD.
 func (b *Bundle) Tidy() error {
-	// refer to #58633
-	// Note that does not explicitly set rule with label.key==EngineLabelKey, because the
+	// refer to tidb#58633
+	// Does not explicitly set exclude rule with label.key==EngineLabelKey, because the
 	// PD may wrongly add peer to the unexpected stores if that key is specified.
 	tempRules := b.Rules[:0]
 	id := 0

pkg/ddl/placement/bundle_test.go

@@ -348,6 +348,7 @@ func TestString(t *testing.T) {
 	rules2, err := newRules(pd.Voter, 4, `["-zone=sh", "+zone=bj"]`)
 	require.NoError(t, err)
 	rules3, err := newRules(pd.Voter, 3, `["-engine=tiflash", "-engine=tiflash_compute"]`)
+	require.NoError(t, err)
 	bundle.Rules = append(append(rules1, rules2...), rules3...)
 
 	require.Equal(t, "{\"group_id\":\"TiDB_DDL_1\",\"group_index\":0,\"group_override\":false,\"rules\":[{\"group_id\":\"\",\"id\":\"\",\"start_key\":\"\",\"end_key\":\"\",\"role\":\"voter\",\"is_witness\":false,\"count\":3,\"label_constraints\":[{\"key\":\"zone\",\"op\":\"in\",\"values\":[\"sh\"]}]},{\"group_id\":\"\",\"id\":\"\",\"start_key\":\"\",\"end_key\":\"\",\"role\":\"voter\",\"is_witness\":false,\"count\":4,\"label_constraints\":[{\"key\":\"zone\",\"op\":\"notIn\",\"values\":[\"sh\"]},{\"key\":\"zone\",\"op\":\"in\",\"values\":[\"bj\"]}]},{\"group_id\":\"\",\"id\":\"\",\"start_key\":\"\",\"end_key\":\"\",\"role\":\"voter\",\"is_witness\":false,\"count\":3,\"label_constraints\":[{\"key\":\"engine\",\"op\":\"notIn\",\"values\":[\"tiflash\"]},{\"key\":\"engine\",\"op\":\"notIn\",\"values\":[\"tiflash_compute\"]}]}]}", bundle.String())