[CALCITE-4893] JsonParseException happens when externalizing expressions with escape character from JSON

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Fix Version/s: 1.31.0
• Assignee: Chunwei Lei
• Reporter: Chunwei Lei
• Created: 18/Nov/21 09:03
• Updated: 03/Aug/22 16:21
• Resolved: 11/Apr/22 23:39

Description

When the expression has escape characters, such as "\r", "\t" and so on, it cannot be externalized correctly. The following test can reproduce the error.

// RelWriterTest.java
@Test void testEscapeCharacter() {
  final FrameworkConfig config = RelBuilderTest.config().build();
  final RelBuilder builder = RelBuilder.create(config);
  final RelNode rel = builder
      .scan("EMP")
      .project(
          builder.call(new MockSqlOperatorTable.SplitFunction(),
              builder.field("ENAME"), builder.literal("\r")))
      .build();
  final String relJson = RelOptUtil.dumpPlan("", rel,
      SqlExplainFormat.JSON, SqlExplainLevel.EXPPLAN_ATTRIBUTES);
  final String s = deserializeAndDumpToTextFormat(getSchema(rel), relJson);
  final String expected = ""
      + "LogicalProject($f0=[SPLIT($1, '\r')])\n"
      + "  LogicalTableScan(table=[[scott, EMP]])\n";
  assertThat(s, isLinux(expected));
} 


FAILURE   3.3sec, org.apache.calcite.plan.RelWriterTest > testEscapeCharacter()
    java.lang.RuntimeException: com.fasterxml.jackson.core.JsonParseException: Illegal unquoted character ((CTRL-CHAR, code 13)): has to be escaped using backslash to be included in string value
     at [Source: (String)"{
      "rels": [
        {
          "id": "0",
          "relOp": "LogicalTableScan",
          "table": [
            "scott",
            "EMP"
          ],
          "inputs": []
        },
        {
          "id": "1",
          "relOp": "LogicalProject",
          "fields": [
            "$f0"
          ],
          "exprs": [
            {
              "op": {
                "name": "SPLIT",
                "kind": "OTHER_FUNCTION",
                "syntax": "FUNCTION"
              },
              "operands": [
                {
                  "input": 1,
                  "name": "$1""[truncated 625 chars]; line: 31, column: 28]
        at org.apache.calcite.tools.Frameworks.withPrepare(Frameworks.java:193)
        at org.apache.calcite.tools.Frameworks.withPlanner(Frameworks.java:135)
        at org.apache.calcite.tools.Frameworks.withPlanner(Frameworks.java:153)
        at org.apache.calcite.plan.RelWriterTest.deserializeAndDump(RelWriterTest.java:1006)
        at org.apache.calcite.plan.RelWriterTest.deserializeAndDumpToTextFormat(RelWriterTest.java:1026)
        at org.apache.calcite.plan.RelWriterTest.testEscapeCharacter(RelWriterTest.java:978)
        Caused by: com.fasterxml.jackson.core.JsonParseException: Illegal unquoted character ((CTRL-CHAR, code 13)): has to be escaped using backslash to be included in string value
         at [Source: (String)"{

Issue Links

• duplicates: CALCITE-5088 Generated model should escape backslashes
• is related to: CALCITE-4884 Provide a new constructor for RelJsonWriter to allow customized JsonBuilder