[sfelixalejandro]

Resolves #228

Overview

In SQLite, collation sequences like COLLATE NOCASE only apply to comparison operators (=, !=, <, >, IN). Built-in scalar functions like instr(X, Y) completely ignore collations attached to their arguments. Additionally, because AshSqlite.Repo sets case_sensitive_like: :on, LIKE in SQLite is also case-sensitive and ignores COLLATE NOCASE.

As reported in #228, queries using contains or string_starts_with against a %Ash.CiString{} or a resource attribute typed as :ci_string were compiled into instr(col, (? COLLATE NOCASE)) or col LIKE ?, failing to match case-insensitively.

Solution

In AshSqlite.SqlImplementation, we intercept Contains, StringStartsWith, and StringEndsWith:

• When either operand is a ci_string (struct %Ash.CiString{}, attribute with storage type :ci_string, calculation, or typed expression):
  • contains/2: compiles to instr(LOWER(left), LOWER(right)) > 0
  • string_starts_with/2: compiles to instr(LOWER(left), LOWER(right)) = 1
  • string_ends_with/2: compiles to like(LOWER(left), escape_pattern)
• When neither operand is a ci_string, it returns :error and falls through to AshSql.Expr's default behaviour, preserving normal case-sensitive behavior without performance overhead.

Tests

• Added unit tests in test/calculation_test.exs verifying case-insensitive matching for contains, string_starts_with, and string_ends_with using both %Ash.CiString{} and :ci_string resource attributes.
• Verified standard strings continue to match case-sensitively.
• Full test suite passing (330/330 tests).

[zachdaniel]

🚀 Thank you for your contribution! 🚀

[sfelixalejandro]

Glad to help! 🚀