test(mutator): add AST mutator validity test#15
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egyptianswitftpigeon wants to merge 9 commits intomainfrom
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test(mutator): add AST mutator validity test#15egyptianswitftpigeon wants to merge 9 commits intomainfrom
egyptianswitftpigeon wants to merge 9 commits intomainfrom
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Bug #1: The reduced() method returns cached constant-folded values from original semantic analysis, not the current mutated value. This caused validation to check wrong values after mutations. Fix: Use node.value directly to get the actual current value after mutation. Add _check_subscript_index_validity() to validate indices and add xfails for negative or out-of-bounds indices. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Bug #1 & #6: Add _check_subscript_context() to validate Int nodes when used as subscript indices or type annotation sizes: - Use node.value directly (not reduced()) to get current mutated value - Detect type annotation context (Bytes[N], String[N], etc.) - Add xfail for array/bytes sizes <= 0 - Add xfail for negative indices - Add xfail for out-of-bounds static array access Call validation after all int literal mutations (_add_one, _subtract_one, _set_zero, _type_aware_mutate). Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Bug #2: bytesM types (bytes1-bytes32) require 0x... syntax, not x"..." syntax. Changed _bytesm_to_ast() to use ast.Hex with 0x prefix instead of ast.HexBytes. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Bug #3: Vyper's constant folding evaluates BOTH branches of ternary expressions before checking the condition. A guard like `0 if (len == 0) else x % len` still fails because Vyper evaluates `x % len` even when len is 0. Fix: Use `max(1, len)` as the divisor instead of ternary guards. This ensures the divisor is always >= 1, preventing divide-by-zero during constant folding. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Bug #4: Vyper does not support len() on static arrays (SArrayT). The builtin only works on DynArray, Bytes, and String types. Fix: In _guarded_index(), check if the sequence is SArrayT and use seq_t.length (the compile-time known length) instead of generating a len() call. Dynamic arrays still use len() for runtime length. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Vyper doesn't support tuple literals on the RHS of assignment statements. This fix prevents generating such invalid code by: - Skipping TupleT targets in generate_assign - Returning False for TupleT in assign mutation is_applicable checks - Excluding TupleT immutables from __init__ initialization Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
For SArrayT, generate indices in the valid range [0, length-1] instead of arbitrary uint256 expressions. Since static array length is known at compile time, we can avoid generating out-of-bounds indices that would cause compilation failures. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add test that validates the mutator produces semantically valid Vyper code: - Parameterized on vyper-exports corpus - Uses deterministic seeds for reproducibility - Verifies mutations actually change the AST - Checks compilation matches xfail expectations Also fix import path in stmt_generator.py (src.fuzzer -> fuzzer). Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Summary
src.fuzzer->fuzzer)Test plan
./ivytest.sh tests/mutator/test_ast_mutator.pyto execute the new testsruff checkandpyright🤖 Generated with Claude Code