plancodec: add test for plan id to avoid change the plan id.

util/plancodec/id.go

@@ -105,47 +105,48 @@ const (
 )
 
 // plan id.
+// Attention: for compatibility of encode/decode plan, The plan id shouldn't be changed.
 const (
-	typeSelID int = iota + 1
-	typeSetID
-	typeProjID
-	typeAggID
-	typeStreamAggID
-	typeHashAggID
-	typeShowID
-	typeJoinID
-	typeUnionID
-	typeTableScanID
-	typeMemTableScanID
-	typeUnionScanID
-	typeIdxScanID
-	typeSortID
-	typeTopNID
-	typeLimitID
-	typeHashJoinID
-	typeMergeJoinID
-	typeIndexJoinID
-	typeIndexMergeJoinID
-	typeIndexHashJoinID
-	typeApplyID
-	typeMaxOneRowID
-	typeExistsID
-	typeDualID
-	typeLockID
-	typeInsertID
-	typeUpdateID
-	typeDeleteID
-	typeIndexLookUpID
-	typeTableReaderID
-	typeIndexReaderID
-	typeWindowID
-	typeTiKVSingleGatherID
-	typeIndexMergeID
-	typePointGet
-	typeShowDDLJobs
-	typeBatchPointGet
-	typeClusterMemTableReader
-	typeDataSourceID
+	typeSelID                 int = 1
+	typeSetID                     = 2
+	typeProjID                    = 3
+	typeAggID                     = 4
+	typeStreamAggID               = 5
+	typeHashAggID                 = 6
+	typeShowID                    = 7
+	typeJoinID                    = 8
+	typeUnionID                   = 9
+	typeTableScanID               = 10
+	typeMemTableScanID            = 11
+	typeUnionScanID               = 12
+	typeIdxScanID                 = 13
+	typeSortID                    = 14
+	typeTopNID                    = 15
+	typeLimitID                   = 16
+	typeHashJoinID                = 17
+	typeMergeJoinID               = 18
+	typeIndexJoinID               = 19
+	typeIndexMergeJoinID          = 20
+	typeIndexHashJoinID           = 21
+	typeApplyID                   = 22
+	typeMaxOneRowID               = 23
+	typeExistsID                  = 24
+	typeDualID                    = 25
+	typeLockID                    = 26
+	typeInsertID                  = 27
+	typeUpdateID                  = 28
+	typeDeleteID                  = 29
+	typeIndexLookUpID             = 30
+	typeTableReaderID             = 31
+	typeIndexReaderID             = 32
+	typeWindowID                  = 33
+	typeTiKVSingleGatherID        = 34
+	typeIndexMergeID              = 35
+	typePointGet                  = 36
+	typeShowDDLJobs               = 37
+	typeBatchPointGet             = 38
+	typeClusterMemTableReader     = 39
+	typeDataSourceID              = 40
 )
 
 // TypeStringToPhysicalID converts the plan type string to plan id.

util/plancodec/id_test.go

@@ -0,0 +1,73 @@
+// Copyright 2020 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package plancodec
+
+import (
+	"testing"
+
+	. "github.com/pingcap/check"
+)
+
+func TestT(t *testing.T) {
+	CustomVerboseFlag = true
+	TestingT(t)
+}
+
+var _ = Suite(&testPlanIDSuite{})
+
+type testPlanIDSuite struct{}
+
+func (s *testPlanIDSuite) TestPlanIDChanged(c *C) {
+	// Attention: For compatibility, shouldn't modify the below test, you can only add test when add new plan ID.
+	c.Assert(typeSelID, Equals, 1)
+	c.Assert(typeSetID, Equals, 2)
+	c.Assert(typeProjID, Equals, 3)
+	c.Assert(typeAggID, Equals, 4)
+	c.Assert(typeStreamAggID, Equals, 5)
+	c.Assert(typeHashAggID, Equals, 6)
+	c.Assert(typeShowID, Equals, 7)
+	c.Assert(typeJoinID, Equals, 8)
+	c.Assert(typeUnionID, Equals, 9)
+	c.Assert(typeTableScanID, Equals, 10)
+	c.Assert(typeMemTableScanID, Equals, 11)
+	c.Assert(typeUnionScanID, Equals, 12)
+	c.Assert(typeIdxScanID, Equals, 13)
+	c.Assert(typeSortID, Equals, 14)
+	c.Assert(typeTopNID, Equals, 15)
+	c.Assert(typeLimitID, Equals, 16)
+	c.Assert(typeHashJoinID, Equals, 17)
+	c.Assert(typeMergeJoinID, Equals, 18)
+	c.Assert(typeIndexJoinID, Equals, 19)
+	c.Assert(typeIndexMergeJoinID, Equals, 20)
+	c.Assert(typeIndexHashJoinID, Equals, 21)
+	c.Assert(typeApplyID, Equals, 22)
+	c.Assert(typeMaxOneRowID, Equals, 23)
+	c.Assert(typeExistsID, Equals, 24)
+	c.Assert(typeDualID, Equals, 25)
+	c.Assert(typeLockID, Equals, 26)
+	c.Assert(typeInsertID, Equals, 27)
+	c.Assert(typeUpdateID, Equals, 28)
+	c.Assert(typeDeleteID, Equals, 29)
+	c.Assert(typeIndexLookUpID, Equals, 30)
+	c.Assert(typeTableReaderID, Equals, 31)
+	c.Assert(typeIndexReaderID, Equals, 32)
+	c.Assert(typeWindowID, Equals, 33)
+	c.Assert(typeTiKVSingleGatherID, Equals, 34)
+	c.Assert(typeIndexMergeID, Equals, 35)
+	c.Assert(typePointGet, Equals, 36)
+	c.Assert(typeShowDDLJobs, Equals, 37)
+	c.Assert(typeBatchPointGet, Equals, 38)
+	c.Assert(typeClusterMemTableReader, Equals, 39)
+	c.Assert(typeDataSourceID, Equals, 40)
+}