LLVM lit framework. Config: e2e-tests/lit.cfg.py.

Running Tests

Always use cmake targets — never run test binaries directly:

cmake --build build -j --target unit-tests e2e-tests

Substitutions

Placeholder	Expands to
sammine / check	sammine / SammineCheck binary paths
full / dir / base	Full .mn path / its directory / basename without .mn
O / I	-O T / -I T — output dir / import search dir flags
T	(lit built-in) Per-test temp output dir

CHECK Directives

# CHECK: match line, # CHECK-NEXT: match next line, # CHECK-ERR: match error output, # CHECK-NOT: assert absence.

Test Patterns

Success — compile + run + check stdout:

# RUN: %sammine --file %full %O && %T/%base.exe | %check %full

# CHECK: expected output line

Error — ! → must fail, 2>&1 → capture stderr:

# RUN: ! %sammine --file %full %O 2>&1 | %check %full

# CHECK: Expected error message substring

Variants: --diagnostics (semantic/type errors, compilables/), --check (ariadne pretty errors, error_reporting/), --diagnostics=dev (source file/line — debug only, not in tests).

Stderr diagnostic — compiler succeeds but emits to stderr (e.g. --llvm-ir pre/post/diff):

# RUN: %sammine --file %full %O --llvm-ir pre 2>&1 | %check %full

For invalid flag values, prefix with !.

Multi-file import — compile library first → .o + .mni in T:

# RUN: %sammine --file %dir/Inputs/math.mn %O && %sammine --file %full %O %I && %T/import_basic.exe | %check %full

Library sources in Inputs/ (excluded from lit). dir locates sibling files. Syntax: import module_name as alias;, C bindings: reuse func(params) -> ret;, exports: export let.

File Organization

Tests in e2e-tests/compilables/ by feature. Naming: feature_variant.mn.

Subfolder	Contents
array/	Fixed-size arrays
ptr/	Pointers & alloc/free
arith/	Arithmetic & integer types
func/	Function calls, recursion
functions/	First-class functions & partial application
control/	Control flow (if, nested_if, if_expr_value)
types/	Type system (var types, records, ...)
misc/	General tests, compiler flags
generics/	Monomorphized generics
enums/	Enum decls, case/match, payloads, generics, unqualified variants
type_inference/	Type inference, numeric literal resolution
import/	Module imports; library sources in Inputs/
typeclass/	Typeclass decls & instances

Other dirs: error_reporting/ — error message regression tests (39 tests). euler/ — Project Euler integration tests.

Error Reporting Test Coverage (error_reporting/)

39 tests covering error messages across compiler phases. Each test uses # RUN: ! sammine --file full O 2>&1 | check full and checks error message substrings.

Category	Tests	Error paths covered
Lexer	single_invalid, double_invalid, multi_invalid_same_line, wide_invalid, unterminated_char	Invalid tokens, unterminated char literal
Type mismatches	return_type_mismatch, if_branch_mismatch, if_cond_not_bool, case_arm_type_mismatch, var_init_mismatch, int_literal_to_float, signed_unsigned_mix	Return type, if branches, if condition, case arms, variable init
Function calls	func_too_many_args, func_arg_type_mismatch, not_callable	Arity, arg type, non-callable
Immutability	immutable_reassign, immutable_array_write	Variable reassign, array index write
Structs	struct_missing_field, struct_field_access_non_struct, unknown_struct_type	Field count, field on non-struct, unknown type
Enums/case	case_non_enum, case_non_exhaustive, case_multi_missing, case_wrong_bindings, case_zero_bindings, enum_wrong_variant, enum_variant_arg_count, invalid_backing_type, enum_discriminant_payload, int_enum_dup_discriminant, int_enum_mixed, int_enum_negative	Exhaustiveness, variant errors, backing types
Linear types	linear_branch_mismatch	Branch consumption inconsistency
Generics	generic_arg_count	Wrong argument count for generic function
Operators	operator_no_instance, no_instance_compare, bitwise_on_float, negate_non_numeric, unsigned_neg	Missing typeclass, bitwise on float, negation
Scope/naming	undeclared_variable, reserved_double_underscore	Undefined var, reserved __
Main signature	main_bad_params, main_wrong_argc_type	Wrong param count/type

Additional error tests live in compilables/ subdirectories (ptr/, array/, linear/, generics/, func/, types/, typeclass/) — these test the same error paths with --diagnostics flag and are not duplicated in error_reporting/.

Still-untested error paths (future work)

Reassigning linear variable without consuming previous value
'name' is not callable for non-function types (partially covered)
Type parameter inference failure (Type parameter 'T' could not be inferred)
Typeclass method not found / wrong arg count
Variadic function arg count errors
Most parser syntax errors (~100 imm_error paths)

README Demo

e2e-tests/compilables/misc/readme_demo.mn mirrors the README "Language Features" block. Keep both in sync; verify compilation after changes.

Gotchas

if/else as statements (not last expr in block) need trailing ; — parser errors without it.
Auxiliary inputs in Inputs/ dirs are excluded from lit discovery.