Intuitive DSL for Java

/*
 * This file is part of the Intuitive DSL project.
 * Copyright (c) 2026 DBA Labs - Switzerland. All rights reserved.
 *
 * This program is dual-licensed under a commercial license and the AGPLv3.
 * For commercial licensing, contact us at [email protected] or visit https://www.dbalabs.ch.
 *
 * AGPLv3 licensing:
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, version 3 (19 November 2007).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/agpl-3.0.html>.
 */

package ch.dbalabs.intuitivedsl.grammar;

import ch.dbalabs.intuitivedsl.exception.DslDefinitionException;
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThatThrownBy;

class DefinitionContractNegativeCoverageTest {

    private final GrammarCompiler compiler = new GrammarCompiler();

    @Test
    void shouldRejectNestedEmptyAlternativeInsideOptionalGroup() {
        assertThatThrownBy(() -> compiler.compile("DO [ { A | | B } ] ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Empty alternative branch");
    }

    @Test
    void shouldRejectNestedEmptyAlternativeInsideRequiredGroup() {
        assertThatThrownBy(() -> compiler.compile("DO { A | [ ] } ;"))
                .isInstanceOf(DslDefinitionException.class);
    }

    @Test
    void shouldRejectCompletelyEmptyOptionalGroup() {
        assertThatThrownBy(() -> compiler.compile("DO [ ] ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Empty optional group");
    }

    @Test
    void shouldRejectCompletelyEmptyRequiredGroup() {
        assertThatThrownBy(() -> compiler.compile("DO { } ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Empty required group");
    }

    @Test
    void shouldRejectEmptyMacroNameInModernSyntax() {
        assertThatThrownBy(() -> compiler.compile("RUN ${} ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Empty macro name");
    }

    @Test
    void shouldRejectEmptyMacroNameInLegacySyntax() {
        assertThatThrownBy(() -> compiler.compile("RUN <> ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Empty legacy macro name");
    }

    @Test
    void shouldRejectDanglingEllipsisWithoutPrecedingNode() {
        assertThatThrownBy(() -> compiler.compile("... RUN target ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("preceding node");
    }

    @Test
    void shouldRejectRepeatedAlternativeSeparatorAtTopLevel() {
        assertThatThrownBy(() -> compiler.compile("DO { A || B } ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Empty alternative branch");
    }

    @Test
    void shouldRejectMismatchedNestedClosersInDeepDefinitions() {
        assertThatThrownBy(() -> compiler.compile("DO { A [ B | C } ] ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Mismatched brackets/braces");
    }

    @Test
    void shouldRejectTrailingEmptyAlternativeInDeepDefinitions() {
        assertThatThrownBy(() -> compiler.compile("DO { A | { B | } } ;"))
                .isInstanceOf(DslDefinitionException.class)
                .hasMessageContaining("Empty alternative branch detected at the end");
    }
}