[FEATURE] Add option to specify custom argument description/list

[Yury-Fridlyand]

Is your feature request related to a problem?

A error returned to user in case if argument(s) are missing or have wrong type(s) is not user-friendly and usually confusing. As more signatures/arguments function has as less readable error become. See examples:

opensearchsql> SELECT PI(1);
{'reason': 'Invalid SQL query', 'details': 'pi function expected {[]}, but get [INTEGER]', 'type': 'ExpressionEvaluationException'}
opensearchsql> SELECT DATEDIFF();
{'reason': 'Invalid SQL query', 'details': 'datediff function expected {[DATE,DATE],[DATETIME,DATE],[DATE,DATETIME],[DATETIME,DATETIME],[DATE,TIME],[TIME,DATE],[TIME,TIME],[TIMESTAMP,DATE],[DATE,TIMESTAMP],[TIMESTAMP,TIMESTAMP],[TIMESTAMP,TIME],[TIME,TIMESTAMP],[TIMESTAMP,DATETIME],[DATETIME,TIMESTAMP],[TIME,DATETIME],[DATETIME,TIME]}, but get []', 'type': 'ExpressionEvaluationException'}

The goal is also to avoid such ugly messages like these:

sql/opensearch/src/test/java/org/opensearch/sql/opensearch/storage/script/filter/FilterQueryBuilderTest.java

Lines 622 to 632 in d81ef73

	assertEquals("simple_query_string function expected {[STRUCT,STRING],[STRUCT,STRING,STRING],"
	+ "[STRUCT,STRING,STRING,STRING],[STRUCT,STRING,STRING,STRING,STRING],[STRUCT,STRING,"
	+ "STRING,STRING,STRING,STRING],[STRUCT,STRING,STRING,STRING,STRING,STRING,STRING],"
	+ "[STRUCT,STRING,STRING,STRING,STRING,STRING,STRING,STRING],[STRUCT,STRING,STRING,"
	+ "STRING,STRING,STRING,STRING,STRING,STRING],[STRUCT,STRING,STRING,STRING,STRING,"
	+ "STRING,STRING,STRING,STRING,STRING],[STRUCT,STRING,STRING,STRING,STRING,STRING,"
	+ "STRING,STRING,STRING,STRING,STRING],[STRUCT,STRING,STRING,STRING,STRING,STRING,"
	+ "STRING,STRING,STRING,STRING,STRING,STRING],[STRUCT,STRING,STRING,STRING,STRING,"
	+ "STRING,STRING,STRING,STRING,STRING,STRING,STRING,STRING],[STRUCT,STRING,STRING,"
	+ "STRING,STRING,STRING,STRING,STRING,STRING,STRING,STRING,STRING,STRING,STRING]},"
	+ " but get [STRUCT]",

What solution would you like?

Add new field to FunctionResolver to store argument/function description. It should be returned (if given) instead of default message, see

sql/core/src/main/java/org/opensearch/sql/expression/function/DefaultFunctionResolver.java

Lines 65 to 68 in e04d6f8

	private String formatFunctions(Set<FunctionSignature> functionSignatures) {
	return functionSignatures.stream().map(FunctionSignature::formatTypes)
	.collect(Collectors.joining(",", "{", "}"));
	}

What alternatives have you considered?

N/a

Do you have any additional context?

• Further improvement for changes done in Rework on error reporting to make it more verbose and human-friendly. #839
• Avoid overloaded error messages for some functions affected by [FEATURE] Add 3 interval types instead of 1 to support complex interval expressions #859

[MaxKsyunz]

Using SELECT PI(1) and SELECT DATEDIFF() as examples, what error message would you like to see?

A common pattern is to say that requested signature is not supported.

SELECT PI(1) it could be PI([INTEGER]) is not a valid function call and similarly for SELECT DATEDIFF() -- DATEDIFF() is not a valid function call.

[Yury-Fridlyand]

For example, for DATEDIFF - DATEDIFF function gets two arguments of any datetime type, but for TIMEDIFF - TIMEDIFF function gets two arguments of any, but same datetime type.