branch coverage complete

// ============================================================================
// VERIFIED REGRESSION TEST - DO NOT MODIFY WITHOUT DISCUSSION
// ============================================================================
// Test 501: Complete branch coverage validation
// Tests that shape checker validates all branches are handled
// Demonstrates: Multi-branch event with complete coverage

~import "$std/io"

// Event with two possible outcomes
~event divide { a: i32, b: i32 }
| ok { result: i32 }
| err { msg: []const u8 }

~proc divide {
    if (b == 0) {
        return .{ .err = .{ .msg = "Division by zero" } };
    }
    return .{ .ok = .{ .result = @divTrunc(a, b) } };
}

// Test: Valid division - should take ok branch
~divide(a: 10, b: 2)
| ok _ |> std.io:println(text: "Success: divided")
| err _ |> std.io:println(text: "Error")

// Test: Division by zero - should take err branch
~divide(a: 10, b: 0)
| ok _ |> std.io:println(text: "Success")
| err _ |> std.io:println(text: "Error: division by zero")