'use strict';

// Tests for single-line comments;

const decomment = require('../lib');
const os = require('os');
const LB = os.EOL;

describe('Single:', function () {

    describe('empty comment', function () {
        it('must return an empty string', function () {
            expect(decomment('//')).toBe('');
            expect(decomment('//text')).toBe('');
        });
    });

    describe('multiple empty comments, space=false', function () {
        it('must return an empty string', function () {
            expect(decomment('//' + LB + '//')).toBe('');
            expect(decomment('//' + LB + '//' + LB)).toBe('');
        });
    });

    describe('multiple empty comments, space=true', function () {
        it('must return line breaks', function () {
            expect(decomment('//' + LB + '//', {space: true})).toBe(LB);
            expect(decomment('//' + LB + '//' + LB, {space: true})).toBe(LB + LB);
        });
    });

    describe('non-empty comment', function () {
        var out = decomment('// text');
        it('must return an empty string', function () {
            expect(out).toBe('');
        });
    });

    describe('non-empty multiple comments', function () {
        var out1 = decomment('// text1' + LB + '// text2');
        var out2 = decomment('// text1' + LB + '// text2' + LB);
        it('must return an empty string', function () {
            expect(out1).toBe('');
            expect(out2).toBe('');
        });
    });

    describe('with a prefix', function () {
        it('must return the prefix', function () {
            expect(decomment(LB + '//')).toBe(LB);
            // spaces and tabs are removed from empty lines:
            expect(decomment(' \t \t')).toBe('');
            expect(decomment('text//comment' + LB)).toBe('text' + LB);
        });
    });

    describe('starting comments suffixed by spaces', function () {
        it('must remove comment and spaces', function () {
            expect(decomment(' //hello ' + LB + 'next')).toBe('next');
            expect(decomment(' \t //hello \t ' + LB + 'next')).toBe('next');
        });
    });

    describe('with line-break suffix', function () {
        var out = decomment('//' + LB);
        it('must return an empty string', function () {
            expect(out).toBe('');
        });
    });

    describe('with multiple line-break suffixes', function () {
        var out = decomment('//' + LB + LB);
        it('must return a single line break', function () {
            expect(out).toBe(LB);
        });
    });

    describe('with preceding text', function () {
        var out1 = decomment('Text//');
        var out2 = decomment(LB + 'Text//');
        var out3 = decomment('Text' + LB + '//');
        var out4 = decomment('Text//' + LB + 'Here');
        it('must return the preceding text', function () {
            expect(out1).toBe('Text');
            expect(out2).toBe(LB + 'Text');
            expect(out3).toBe('Text' + LB);
            expect(out4).toBe('Text' + LB + 'Here');
        });
    });

    describe('with empty text prefix', function () {
        var out1 = decomment('\'\'//');
        var out2 = decomment('\'\'//');
        var out3 = decomment('``//');
        it('must leave only the comment', function () {
            expect(out1).toBe('\'\'');
            expect(out2).toBe('\'\'');
            expect(out3).toBe('``');
        });
    });

    describe('with empty text suffix', function () {
        var out1 = decomment('//' + LB + '\'\'');
        var out2 = decomment('//' + LB + '\'\'');
        var out3 = decomment('//' + LB + '``');
        it('must leave only the comment', function () {
            expect(out1).toBe('\'\'');
            expect(out2).toBe('\'\'');
            expect(out3).toBe('``');
        });
    });

    describe('comments inside text', function () {
        var out = decomment('\'//Text\'');
        it('must leave only the comment', function () {
            expect(out).toBe('\'//Text\'');
        });
    });

    describe('spaces', function () {
        describe('before text', function () {
            var out = decomment('\t \tText');
            it('must preserve the spaces', function () {
                expect(out).toBe('\t \tText');
            });
        });
        describe('after text', function () {
            var out = decomment('Text\t \t');
            it('must preserve the spaces', function () {
                expect(out).toBe('Text\t \t');
            });
        });
        describe('complex case', function () {
            var out = decomment('a // comment' + LB + '\tb // comment' + LB + 'c//end');
            it('must keep spaces correctly', function () {
                expect(out).toBe('a ' + LB + '\tb ' + LB + 'c');
            });
        });
    });

    describe('multiple line breaks that follow', function () {
        it('must be removed', function () {
            expect(decomment('//text' + LB + LB + 'end', {trim: true})).toBe('end');
            expect(decomment('//text' + LB + '\t' + LB + 'end', {trim: true})).toBe('end');
        });
    });

    describe('inside regEx', function () {
        it('must be ignored', function () {
            expect(decomment('/[a-b//]text/')).toBe('/[a-b//]text/');
        });
    });
});