crytic crashes when running on my project

[baseballlover723]

cryptic crashes when I run it on my project (https://github.com/baseballlover723/lol-worlds-draw/tree/failing_cryptic) when running bin/crytic -s src/lol/worlds/draw.cr spec/lol/worlds/draw_spec.cr

Running 9 mutations.
    ✅ NumberLiteralChange
        in src/lol/worlds/draw.cr:6:34
    ✅ NumberLiteralChange
        in src/lol/worlds/draw.cr:9:36
    ❌ NumberLiteralChange
        in src/lol/worlds/draw.cr:12:49
        The following change didn't fail the test-suite:
            @@ -8,7 +8,7 @@
                     Group.new
                   end
                 end
            -    def initialize(groups : StaticArray(Group, 4))
            +    def initialize(groups : StaticArray(Group, 0))
                   @groups = groups
                 end
                 def self.new(pull : JSON::PullParser)

    ✅ NumberLiteralChange
        in src/lol/worlds/draw.cr:25:15
    ✅ NumberLiteralChange
        in src/lol/worlds/draw.cr:28:18Unhandled exception: unexpected token: -1 (Crystal::SyntaxException)
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/lexer.cr:3090:9 in 'raise'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/lexer.cr:3089:5 in 'raise'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:6002:9 in 'unexpected_token'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:5998:5 in 'unexpected_token'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4782:9 in 'parse_atomic_type'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4715:7 in 'parse_atomic_type_with_suffix'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4702:7 in 'parse_union_type'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4938:7 in 'parse_atomic_type'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4715:7 in 'parse_atomic_type_with_suffix'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4702:7 in 'parse_union_type'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4958:9 in 'parse_type_arg'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4938:7 in 'parse_type_args'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4813:7 in 'parse_generic'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4808:7 in 'parse_generic'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4799:5 in 'parse_generic'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4740:9 in 'parse_atomic_type'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4715:7 in 'parse_atomic_type_with_suffix'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4702:7 in 'parse_union_type'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4938:7 in 'parse_bare_proc_type'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:1189:7 in 'parse_type_declaration'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:1227:9 in 'new_node_check_type_declaration'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:1164:9 in 'parse_atomic_without_location'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:925:7 in 'parse_atomic'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:608:7 in 'parse_atomic_with_method'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:600:9 in 'parse_prefix'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:582:5 in 'parse_pow'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:581:5 in 'parse_mul_or_div'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:545:7 in 'parse_add_or_sub'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:540:5 in 'parse_shift'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:539:5 in 'parse_logical_and'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:538:5 in 'parse_logical_or'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:537:5 in 'parse_cmp'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:536:5 in 'parse_equality'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:535:5 in 'parse_and'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:534:5 in 'parse_or'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:475:9 in 'parse_range'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:444:7 in 'parse_question_colon'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:328:7 in 'parse_op_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:324:5 in 'parse_op_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:260:7 in 'parse_expression'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:137:7 in 'parse_multi_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:113:7 in 'parse_expressions_internal'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4174:7 in 'parse_expressions'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:6024:7 in 'parse_class_def'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:1606:5 in 'parse_class_def'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:1084:15 in 'parse_atomic_without_location'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:925:7 in 'parse_atomic'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:608:7 in 'parse_atomic_with_method'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:600:9 in 'parse_prefix'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:582:5 in 'parse_pow'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:581:5 in 'parse_mul_or_div'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:545:7 in 'parse_add_or_sub'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:540:5 in 'parse_shift'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:539:5 in 'parse_logical_and'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:538:5 in 'parse_logical_or'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:537:5 in 'parse_cmp'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:536:5 in 'parse_equality'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:535:5 in 'parse_and'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:534:5 in 'parse_or'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:475:9 in 'parse_range'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:444:7 in 'parse_question_colon'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:328:7 in 'parse_op_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:324:5 in 'parse_op_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:260:7 in 'parse_expression'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:137:7 in 'parse_multi_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:113:7 in 'parse_expressions_internal'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4174:7 in 'parse_expressions'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:6024:7 in 'parse_module_def'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:1096:15 in 'parse_atomic_without_location'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:925:7 in 'parse_atomic'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:608:7 in 'parse_atomic_with_method'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:600:9 in 'parse_prefix'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:582:5 in 'parse_pow'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:581:5 in 'parse_mul_or_div'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:545:7 in 'parse_add_or_sub'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:540:5 in 'parse_shift'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:539:5 in 'parse_logical_and'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:538:5 in 'parse_logical_or'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:537:5 in 'parse_cmp'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:536:5 in 'parse_equality'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:535:5 in 'parse_and'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:534:5 in 'parse_or'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:475:9 in 'parse_range'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:444:7 in 'parse_question_colon'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:328:7 in 'parse_op_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:324:5 in 'parse_op_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:260:7 in 'parse_expression'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:137:7 in 'parse_multi_assign'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:126:17 in 'parse_expressions_internal'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:4174:7 in 'parse_expressions'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:84:21 in 'parse'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/parser.cr:24:7 in 'parse'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:23:19 in 'process'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:78:11 in 'visit'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/visitor.cr:27:12 in 'accept'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/ast.cr:169:27 in 'accept_children'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/visitor.cr:28:11 in 'accept'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:24:9 in 'process'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:78:11 in 'visit'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/visitor.cr:27:12 in 'accept'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/ast.cr:169:27 in 'accept_children'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/visitor.cr:28:11 in 'accept'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:24:9 in 'process'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:78:11 in 'visit'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/visitor.cr:27:12 in 'accept'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/ast.cr:169:27 in 'accept_children'
  from ../../../../../../../usr/share/crystal/src/compiler/crystal/syntax/visitor.cr:28:11 in 'accept'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:24:9 in 'process'
  from lib/crytic/src/crytic/mutation/inject_mutated_subject_into_specs.cr:32:9 in 'to_mutated_source'
  from lib/crytic/src/crytic/mutation/isolated_mutation.cr:86:9 in 'mutated_specs_source'
  from lib/crytic/src/crytic/mutation/isolated_mutation.cr:58:45 in 'write_full_source_into_tempfile'
  from lib/crytic/src/crytic/mutation/isolated_mutation.cr:41:7 in 'run'
  from lib/crytic/src/crytic/mutation/isolated_mutation.cr:18:24 in 'run'
  from lib/crytic/src/crytic/runner/sequential.cr:20:18 in 'run_mutations_for_single_subject'
  from lib/crytic/src/crytic/runner/sequential.cr:38:11 in 'run_all_mutations'
  from lib/crytic/src/crytic/runner/sequential.cr:13:17 in 'run'
  from lib/crytic/src/crytic/command/test.cr:19:5 in 'execute'
  from lib/crytic/src/crytic/cli.cr:19:9 in 'run'
  from lib/crytic/src/crytic.cr:5:12 in '__crystal_main'
  from ../../../../../../../usr/share/crystal/src/crystal/main.cr:105:5 in 'main_user_code'
  from ../../../../../../../usr/share/crystal/src/crystal/main.cr:91:7 in 'main'
  from ../../../../../../../usr/share/crystal/src/crystal/main.cr:114:3 in 'main'
  from __libc_start_main
  from _start
  from ???

Crystal Info

LLVM: 8.0.0
Default target: x86_64-unknown-linux-gnu

[hanneskaeufler]

Hi @baseballlover723, thanks for reporting the bug. I just had a look and indeed, what happens is that we apply the NumberLiteralSignFlip mutation, which leads to

    @groups : StaticArray(Group, (-1*4))

which is not valid syntax in crystal. Actually, regardless of syntax, flipping the 4 to -4 isn't valid crystal either way and doesn't compile

In src/lol/worlds/draw.cr:6:15

 6 | @groups : StaticArray(Group, -4)
               ^
Error: can't instantiate StaticArray(T, N) with N = -4 (N must be positive)

I haven't taken such constructs (where e.g. changing a number leads to invalid syntax) into consideration so far. One way forward would be to allow disabling of mutators, as you suggested in #85. Or we could make mutators be aware of these cases and not mutate. That would be my preference for now, but not sure how to even know when changing the number would literal be invalid. I'll look around a bit to see what can be done ... :)