004 shape error

✓ Passing This code compiles and runs correctly.

Code

// Test 355_004: Optional Branches - Shape Validation Still Applies
//
// Verifies:
// 1. Optional branches are still subject to shape checking
// 2. "Optional" means "can be omitted", NOT "can be misused"
// 3. Handling a nonexistent branch name = compile error

~import std/io

// Event with required + optional branch
~event process { value: u32 }
| success u32        // REQUIRED
| ?warning []const u8   // OPTIONAL

~proc process|zig {
    if (value > 100) {
        return .{ .warning = "Value too large" };
    }
    return .{ .success = value * 2 };
}

// Handler references a branch that doesn't exist on this event
// "nonexistent" is not a branch of process — should fail compilation
~process(value: 150)
| success _ |> std/io:print.ln("OK")
| nonexistent _ |> std/io:print.ln("BAD")

input.kz

Backend must reject with:

CONTAINS error[KORU021]
CONTAINS has no branch 'nonexistent'

Error Verification

Actual Compiler Output

error[KORU021]: event 'input:process' has no branch 'nonexistent' (available: success, warning)
  --> tests/regression/300_ADVANCED_FEATURES/355_OPTIONAL_BRANCHES/355_004_shape_error/input.kz:25:0

❌ Compiler coordination error: Incomplete branch coverage
error: CompilerCoordinationFailed
/Users/larsde/src/koru/tests/regression/300_ADVANCED_FEATURES/355_OPTIONAL_BRANCHES/355_004_shape_error/backend.zig:94:13: 0x100d4f18f in emit (backend)
            return error.CompilerCoordinationFailed;
            ^
/Users/larsde/src/koru/tests/regression/300_ADVANCED_FEATURES/355_OPTIONAL_BRANCHES/355_004_shape_error/backend.zig:190:28: 0x100d4fe7b in main (backend)
    const generated_code = try RuntimeEmitter.emit(compile_allocator, final_ast);
                           ^

Test Configuration

MUST_FAIL

← 003 ignored no catchall 005 all optional →