EoIndentLexerTest.java

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2016-2024 Objectionary.com
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
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 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
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package org.eolang.parser;

import java.io.IOException;
import org.cactoos.text.TextOf;
import org.hamcrest.MatcherAssert;
import org.hamcrest.Matchers;
import org.junit.jupiter.api.Test;

/**
 * Test for {@link EoIndentLexer}.
 *
 * @since 1.0
 */
final class EoIndentLexerTest {
    /**
     * Empty message for JUnit Assertions.
     */
    private static final String EMPTY_MSG = "EMPTY MESSAGE";

    @Test
    void emitsTab() throws IOException {
        final EoIndentLexer lexer = new EoIndentLexer(
            new TextOf("\n  ")
        );
        lexer.nextToken();
        MatcherAssert.assertThat(
            EoIndentLexerTest.EMPTY_MSG,
            lexer.nextToken().getType(),
            Matchers.is(
                EoParser.TAB
            )
        );
    }

    @Test
    void ensuresGrammarFile() throws IOException {
        final EoIndentLexer lexer = new EoIndentLexer(
            new TextOf("")
        );
        MatcherAssert.assertThat(
            EoIndentLexerTest.EMPTY_MSG,
            lexer.getGrammarFileName(),
            Matchers.is(
                "Eo.g4"
            )
        );
    }

    @Test
    void emitsTabWhenEmptyLine() throws IOException {
        final EoIndentLexer lexer = new EoIndentLexer(
            new TextOf("\n\n  ")
        );
        lexer.nextToken();
        MatcherAssert.assertThat(
            EoIndentLexerTest.EMPTY_MSG,
            lexer.nextToken().getType(),
            Matchers.is(
                EoParser.TAB
            )
        );
    }

    @Test
    void emitsUntab() throws IOException {
        final EoIndentLexer lexer = new EoIndentLexer(
            new TextOf("\n  \n  \n")
        );
        lexer.nextToken();
        lexer.nextToken();
        lexer.nextToken();
        MatcherAssert.assertThat(
            EoIndentLexerTest.EMPTY_MSG,
            lexer.nextToken().getType(),
            Matchers.is(
                EoParser.UNTAB
            )
        );
    }

    @Test
    void readsEmptyString() throws IOException {
        final EoIndentLexer lexer = new EoIndentLexer(
            new TextOf("")
        );
        MatcherAssert.assertThat(
            EoIndentLexerTest.EMPTY_MSG,
            lexer.nextToken().getType(),
            Matchers.is(
                EoParser.EOF
            )
        );
    }
}