svelte/src/utils/__test__.ts

import * as assert from 'assert';
import deindent from './deindent.js';
import CodeBuilder from './CodeBuilder.ts';

describe( 'deindent', () => {
	it( 'deindents a simple string', () => {
		const deindented = deindent`
			deindent me please
		`;

		assert.equal( deindented, `deindent me please` );
	});

	it( 'deindents a multiline string', () => {
		const deindented = deindent`
			deindent me please
			and me as well
		`;

		assert.equal( deindented, `deindent me please\nand me as well` );
	});

	it( 'preserves indentation of inserted values', () => {
		const insert = deindent`
			line one
			line two
		`;

		const deindented = deindent`
			before
				${insert}
			after
		`;

		assert.equal( deindented, `before\n\tline one\n\tline two\nafter` );
	});
});

describe( 'CodeBuilder', () => {
	it( 'creates an empty block', () => {
		const builder = new CodeBuilder();
		assert.equal( builder.toString(), '' );
	});

	it( 'creates a block with a line', () => {
		const builder = new CodeBuilder();

		builder.addLine( 'var answer = 42;' );
		assert.equal( builder.toString(), 'var answer = 42;' );
	});

	it( 'creates a block with two lines', () => {
		const builder = new CodeBuilder();

		builder.addLine( 'var problems = 99;' );
		builder.addLine( 'var answer = 42;' );
		assert.equal( builder.toString(), 'var problems = 99;\nvar answer = 42;' );
	});

	it( 'adds newlines around blocks', () => {
		const builder = new CodeBuilder();

		builder.addLine( '// line 1' );
		builder.addLine( '// line 2' );
		builder.addBlock( deindent`
			if ( foo ) {
				bar();
			}
		` );
		builder.addLine( '// line 3' );
		builder.addLine( '// line 4' );

		assert.equal( builder.toString(), deindent`
			// line 1
			// line 2

			if ( foo ) {
				bar();
			}

			// line 3
			// line 4
		` );
	});

	it( 'nests codebuilders with correct indentation', () => {
		const child = new CodeBuilder();

		child.addBlock( deindent`
			var obj = {
				answer: 42
			};
		` );

		const builder = new CodeBuilder();

		builder.addLine( '// line 1' );
		builder.addLine( '// line 2' );
		builder.addBlock( deindent`
			if ( foo ) {
				${child}
			}
		` );
		builder.addLine( '// line 3' );
		builder.addLine( '// line 4' );

		assert.equal( builder.toString(), deindent`
			// line 1
			// line 2

			if ( foo ) {
				var obj = {
					answer: 42
				};
			}

			// line 3
			// line 4
		` );
	});

	it( 'adds a line at start', () => {
		const builder = new CodeBuilder();

		builder.addLine( '// second' );
		builder.addLineAtStart( '// first' );

		assert.equal( builder.toString(), deindent`
			// first
			// second
		` );
	});

	it( 'adds a line at start before a block', () => {
		const builder = new CodeBuilder();

		builder.addBlock( '// second' );
		builder.addLineAtStart( '// first' );

		assert.equal( builder.toString(), deindent`
			// first

			// second
		` );
	});

	it( 'adds a block at start', () => {
		const builder = new CodeBuilder();

		builder.addLine( '// second' );
		builder.addBlockAtStart( '// first' );

		assert.equal( builder.toString(), deindent`
			// first

			// second
		` );
	});

	it( 'adds a block at start before a block', () => {
		const builder = new CodeBuilder();

		builder.addBlock( '// second' );
		builder.addBlockAtStart( '// first' );

		assert.equal( builder.toString(), deindent`
			// first

			// second
		` );
	});
});