[CALCITE-2688] Improve diagnosability when return type could not be inferred.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.18.0
• Assignee: Zoltan Haindrich
• Reporter: Zoltan Haindrich
• Created: 20/Nov/18 15:02
• Updated: 23/Dec/18 00:12
• Resolved: 03/Dec/18 14:56

Description

Currently when the return type inferenence fails; a null is returned; while leads to an NPE very quickly - the resulting Exception is not informative at all.

  @Test(expected = IllegalArgumentException.class)
  public void checkNoCommonReturnTypeException() {
    coalesce(vVarchar(1), vInt(2));
  }

example NPE:

java.lang.NullPointerException
	at java.util.Objects.requireNonNull(Objects.java:203)
	at org.apache.calcite.rex.RexCall.<init>(RexCall.java:59)
	at org.apache.calcite.rex.RexBuilder.makeCall(RexBuilder.java:242)
	at org.apache.calcite.rex.RexBuilder.makeCall(RexBuilder.java:254)
	at org.apache.calcite.test.RexProgramBuilderBase.coalesce(RexProgramBuilderBase.java:300)
	at org.apache.calcite.test.RexProgramTest.checkNoCommonReturnTypeException(RexProgramTest.java:753)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

Issue Links

• links to: pr930