Better error messages (hashtag2726)

[vikramsubramanian]

• [x] Non-existing function in CALL: I am not sure if this applies to non-existing function calls in other expressions but in CALL the following happens:

  kuzu> CALL show_table("small_r") RETURN *;
  Error: unordered_map::at: key not found

  Let's say something like: "show_table is not a valid function name".

• [x] Non-existing node table:

  MATCH (a:kz_ex_rt) RETURN *;
  Error: Assertion failed in file "/Users/ssalihog/projects/vs-code-projects/kuzu/kuzu-master/src/binder/bind/bind_graph_pattern.cpp" on line 606: KU_UNREACHABLE

  Let's say something like: "kz_ex_rt is not a valid node table name". )

[mayil-ai[bot]]

Summary: Improved error messages for non-existing function and node table names in CALL and MATCH queries.

Possible Solution

Based on the provided information and code snippets, here is a solution to address the issue:

• Improve error handling for non-existing function calls in CALL expressions:

  • In src/function/table_functions/call_functions.cpp, implement a check to validate the function name against the list of available functions defined in src/include/common/enums/expression_type.h.
  • If the function name is not found, throw a BinderException with a clear error message indicating the function does not exist.

• Improve error handling for non-existing node table names in MATCH expressions:

  • In src/binder/bind/bind_graph_pattern.cpp, before line 606, add a check to validate the node table name using the validate_node_table_name function.
  • If the node table name is not valid, throw a BinderException with a clear error message indicating the node table does not exist.

• Update the unordered_map usage to handle the "key not found" error gracefully:

  • Wherever unordered_map::at is used, wrap it in a try-catch block to catch std::out_of_range exceptions.
  • In the catch block, throw a BinderException with a user-friendly error message.

• Address the assertion failure in bind_graph_pattern.cpp on line 606:

  • Replace the KU_UNREACHABLE assertion with a conditional check and a BinderException if the condition is not met.
  • Ensure that the condition being asserted is properly validated before reaching this line of code.

• Update error messages to be more informative:

  • Modify the BinderException class to include additional context such as the query part that caused the error and suggestions for possible fixes.
  • Update the getErrorMessage method in tools/java_api/src/test/java/com/kuzudb/test/QueryResultTest.java to return the enhanced error messages.

• Ensure that all changes are thoroughly tested:

  • Add unit tests for the new validation functions validate_function_name and validate_node_table_name.
  • Add unit tests for the updated error handling in CALL and MATCH expressions.
  • Update existing tests to check for the new error messages and ensure they are informative and accurate.

Code snippets to check

• src/binder/bind/bind_graph_pattern.cpp

  This file contains the code for binding graph patterns, which is relevant to the issue of providing better error messages for non-existing node table names.

• src/binder/bind_expression/bind_function_expression.cpp

  This file is responsible for binding function expressions, which is relevant to the issue of providing better error messages for non-existing function calls.

• src/function/table_functions/call_functions.cpp

  This file deals with the implementation of table functions, which may need to be modified to provide better error messages for non-existing function calls.

• src/include/common/enums/expression_type.h

  This file defines function names, which may be used to check for the existence of functions and provide better error messages.