test/dart_formatter_test.dart - dart_style - Git at Google

 // Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 import 'package:dart_style/dart_style.dart';
 import 'package:pub_semver/pub_semver.dart';
 import 'package:test/test.dart';

 void main() async {
   group('short style', () {
     _runTests(isTall: false);
   });

   group('tall style', () {
     _runTests(isTall: true);
   });
 }

 /// Run all of the DartFormatter tests either using short or tall style.
 void _runTests({required bool isTall}) {
   DartFormatter makeFormatter({
     Version? languageVersion,
     int? indent,
     String? lineEnding,
   }) {
     languageVersion ??=
         isTall
             ? DartFormatter.latestLanguageVersion
             : DartFormatter.latestShortStyleLanguageVersion;

     return DartFormatter(
       languageVersion: languageVersion,
       indent: indent,
       lineEnding: lineEnding,
     );
   }

   group('language version', () {
     test('defaults to latest if omitted', () {
       var formatter = makeFormatter();
       expect(
         formatter.languageVersion,
         isTall
             ? DartFormatter.latestLanguageVersion
             : DartFormatter.latestShortStyleLanguageVersion,
       );
     });

     test('parses at given older language version', () {
       // Use a language version before patterns were supported and a pattern
       // is an error.
       var formatter = makeFormatter(languageVersion: Version(2, 19, 0));
       expect(
         () => formatter.format('main() {switch (o) {case var x: break;}}'),
         throwsA(isA<FormatterException>()),
       );
     });

     test('parses at given newer language version', () {
       // Use a language version after patterns were supported and `1 + 2` is an
       // error.
       var formatter = makeFormatter(languageVersion: Version(3, 0, 0));
       expect(
         () => formatter.format('main() {switch (o) {case 1+2: break;}}'),
         throwsA(isA<FormatterException>()),
       );
     });

     test('@dart comment overrides version', () {
       // Use a language version after patterns were supported and `1 + 2` is an
       // error.
       var formatter = makeFormatter(languageVersion: Version(3, 0, 0));

       // But then have the code opt to the older version.
       const before = '''
 // @dart=2.19
 main() { switch (o) { case 1+2: break; } }
 ''';

       const after = '''
 // @dart=2.19
 main() {
   switch (o) {
     case 1 + 2:
       break;
   }
 }
 ''';

       expect(formatter.format(before), after);
     });
   });

   test('language version comment override opts into short style', () async {
     // Use a language version with tall style.
     var formatter = makeFormatter(languageVersion: Version(3, 7, 0));

     // But the code has a comment to opt into the short style.
     const before = '''
 // @dart=3.6
 main() { f(argument, // comment
 another);}
 ''';
     const after = '''
 // @dart=3.6
 main() {
   f(
       argument, // comment
       another);
 }
 ''';

     expect(formatter.format(before), after);
   });

   test('language version comment override opts into tall style', () async {
     // Use a language version with short style.
     var formatter = makeFormatter(languageVersion: Version(3, 6, 0));

     // But the code has a comment to opt into the tall style.
     //
     // Note that in real-world code it doesn't make sense for a language
     // version comment to be *higher* than the specified default language
     // version before you can't use a comment that's higher than the minimum
     // version in the package's SDK constraint. (Otherwise, you could end up
     // trying to run a library whose language version isn't supported by the
     // SDK you are running it in.)
     //
     // But we support it in the formatter since it's possible to specify a
     // default language version using mechanisms other than the pubspec SDK
     // constraint.
     const before = '''
 // @dart=3.7
 main() { f(argument, // comment
 another);}
 ''';
     const after = '''
 // @dart=3.7
 main() {
   f(
     argument, // comment
     another,
   );
 }
 ''';

     expect(formatter.format(before), after);
   });

   test('throws a FormatterException on failed parse', () {
     var formatter = makeFormatter();
     expect(() => formatter.format('wat?!'), throwsA(isA<FormatterException>()));
   });

   test('FormatterException.message() does not throw', () {
     // This is a regression test for #358 where an error whose position is
     // past the end of the source caused FormatterException to throw.
     expect(
       () => makeFormatter().format('library'),
       throwsA(
         isA<FormatterException>().having(
           (e) => e.message(),
           'message',
           contains('Could not format'),
         ),
       ),
     );
   });

   test('FormatterException describes parse errors', () {
     expect(
       () {
         makeFormatter().format('''

       var a = some error;

       var b = another one;
       ''', uri: 'my_file.dart');

         fail('Should throw.');
       },
       throwsA(
         isA<FormatterException>().having(
           (e) => e.message(),
           'message',
           allOf(
             contains('Could not format'),
             contains('line 2'),
             contains('line 4'),
           ),
         ),
       ),
     );
   });

   test('adds newline to unit', () {
     expect(makeFormatter().format('var x = 1;'), equals('var x = 1;\n'));
   });

   test('adds newline to unit after trailing comment', () {
     expect(
       makeFormatter().format('library foo; //zamm'),
       equals('library foo; //zamm\n'),
     );
   });

   test('removes extra newlines', () {
     expect(makeFormatter().format('var x = 1;\n\n\n'), equals('var x = 1;\n'));
   });

   test('does not add newline to statement', () {
     expect(makeFormatter().formatStatement('var x = 1;'), equals('var x = 1;'));
   });

   test('fails if anything is after the statement', () {
     expect(
       () => makeFormatter().formatStatement('var x = 1;;'),
       throwsA(
         isA<FormatterException>()
             .having((e) => e.errors.length, 'errors.length', equals(1))
             .having(
               (e) => e.errors.first.offset,
               'errors.length.first.offset',
               equals(10),
             ),
       ),
     );
   });

   test('preserves initial indent', () {
     var formatter = makeFormatter(indent: 3);
     expect(
       formatter.formatStatement('if (foo) {bar;}'),
       equals(
         '   if (foo) {\n'
         '     bar;\n'
         '   }',
       ),
     );
   });

   group('line endings', () {
     test('uses given line ending', () {
       // Use zero width no-break space character as the line ending. We have
       // to use a whitespace character for the line ending as the formatter
       // will throw an error if it accidentally makes non-whitespace changes
       // as would occur if we used a non-whitespace character as the line
       // ending.
       var lineEnding = '\t';
       expect(
         makeFormatter(lineEnding: lineEnding).format('var i = 1;'),
         equals('var i = 1;\t'),
       );
     });

     test('infers \\r\\n if the first newline uses that', () {
       expect(
         makeFormatter().format('var\r\ni\n=\n1;\n'),
         equals('var i = 1;\r\n'),
       );
     });

     test('infers \\n if the first newline uses that', () {
       expect(
         makeFormatter().format('var\ni\r\n=\r\n1;\r\n'),
         equals('var i = 1;\n'),
       );
     });

     test('defaults to \\n if there are no newlines', () {
       expect(makeFormatter().format('var i =1;'), equals('var i = 1;\n'));
     });

     test('handles Windows line endings in multiline strings', () {
       expect(
         makeFormatter(lineEnding: '\r\n').formatStatement(
           '  """first\r\n'
           'second\r\n'
           'third"""  ;',
         ),
         equals(
           '"""first\r\n'
           'second\r\n'
           'third""";',
         ),
       );
     });
   });

   test('throws an UnexpectedOutputException on non-whitespace changes', () {
     // Use an invalid line ending character to ensure the formatter will
     // attempt to make non-whitespace changes.
     var formatter = makeFormatter(lineEnding: '%');
     expect(
       () => formatter.format('var i = 1;'),
       throwsA(isA<UnexpectedOutputException>()),
     );
   });
 }
	// Copyright (c) 2024, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	import 'package:dart_style/dart_style.dart';
	import 'package:pub_semver/pub_semver.dart';
	import 'package:test/test.dart';

	void main() async {
	group('short style', () {
	_runTests(isTall: false);
	});

	group('tall style', () {
	_runTests(isTall: true);
	});
	}

	/// Run all of the DartFormatter tests either using short or tall style.
	void _runTests({required bool isTall}) {
	DartFormatter makeFormatter({
	Version? languageVersion,
	int? indent,
	String? lineEnding,
	}) {
	languageVersion ??=
	isTall
	? DartFormatter.latestLanguageVersion
	: DartFormatter.latestShortStyleLanguageVersion;

	return DartFormatter(
	languageVersion: languageVersion,
	indent: indent,
	lineEnding: lineEnding,
	);
	}

	group('language version', () {
	test('defaults to latest if omitted', () {
	var formatter = makeFormatter();
	expect(
	formatter.languageVersion,
	isTall
	? DartFormatter.latestLanguageVersion
	: DartFormatter.latestShortStyleLanguageVersion,
	);
	});

	test('parses at given older language version', () {
	// Use a language version before patterns were supported and a pattern
	// is an error.
	var formatter = makeFormatter(languageVersion: Version(2, 19, 0));
	expect(
	() => formatter.format('main() {switch (o) {case var x: break;}}'),
	throwsA(isA<FormatterException>()),
	);
	});

	test('parses at given newer language version', () {
	// Use a language version after patterns were supported and `1 + 2` is an
	// error.
	var formatter = makeFormatter(languageVersion: Version(3, 0, 0));
	expect(
	() => formatter.format('main() {switch (o) {case 1+2: break;}}'),
	throwsA(isA<FormatterException>()),
	);
	});

	test('@dart comment overrides version', () {
	// Use a language version after patterns were supported and `1 + 2` is an
	// error.
	var formatter = makeFormatter(languageVersion: Version(3, 0, 0));

	// But then have the code opt to the older version.
	const before = '''
	// @dart=2.19
	main() { switch (o) { case 1+2: break; } }
	''';

	const after = '''
	// @dart=2.19
	main() {
	switch (o) {
	case 1 + 2:
	break;
	}
	}
	''';

	expect(formatter.format(before), after);
	});
	});

	test('language version comment override opts into short style', () async {
	// Use a language version with tall style.
	var formatter = makeFormatter(languageVersion: Version(3, 7, 0));

	// But the code has a comment to opt into the short style.
	const before = '''
	// @dart=3.6
	main() { f(argument, // comment
	another);}
	''';
	const after = '''
	// @dart=3.6
	main() {
	f(
	argument, // comment
	another);
	}
	''';

	expect(formatter.format(before), after);
	});

	test('language version comment override opts into tall style', () async {
	// Use a language version with short style.
	var formatter = makeFormatter(languageVersion: Version(3, 6, 0));

	// But the code has a comment to opt into the tall style.
	//
	// Note that in real-world code it doesn't make sense for a language
	// version comment to be higher than the specified default language
	// version before you can't use a comment that's higher than the minimum
	// version in the package's SDK constraint. (Otherwise, you could end up
	// trying to run a library whose language version isn't supported by the
	// SDK you are running it in.)
	//
	// But we support it in the formatter since it's possible to specify a
	// default language version using mechanisms other than the pubspec SDK
	// constraint.
	const before = '''
	// @dart=3.7
	main() { f(argument, // comment
	another);}
	''';
	const after = '''
	// @dart=3.7
	main() {
	f(
	argument, // comment
	another,
	);
	}
	''';

	expect(formatter.format(before), after);
	});

	test('throws a FormatterException on failed parse', () {
	var formatter = makeFormatter();
	expect(() => formatter.format('wat?!'), throwsA(isA<FormatterException>()));
	});

	test('FormatterException.message() does not throw', () {
	// This is a regression test for #358 where an error whose position is
	// past the end of the source caused FormatterException to throw.
	expect(
	() => makeFormatter().format('library'),
	throwsA(
	isA<FormatterException>().having(
	(e) => e.message(),
	'message',
	contains('Could not format'),
	),
	),
	);
	});

	test('FormatterException describes parse errors', () {
	expect(
	() {
	makeFormatter().format('''

	var a = some error;

	var b = another one;
	''', uri: 'my_file.dart');

	fail('Should throw.');
	},
	throwsA(
	isA<FormatterException>().having(
	(e) => e.message(),
	'message',
	allOf(
	contains('Could not format'),
	contains('line 2'),
	contains('line 4'),
	),
	),
	),
	);
	});

	test('adds newline to unit', () {
	expect(makeFormatter().format('var x = 1;'), equals('var x = 1;\n'));
	});

	test('adds newline to unit after trailing comment', () {
	expect(
	makeFormatter().format('library foo; //zamm'),
	equals('library foo; //zamm\n'),
	);
	});

	test('removes extra newlines', () {
	expect(makeFormatter().format('var x = 1;\n\n\n'), equals('var x = 1;\n'));
	});

	test('does not add newline to statement', () {
	expect(makeFormatter().formatStatement('var x = 1;'), equals('var x = 1;'));
	});

	test('fails if anything is after the statement', () {
	expect(
	() => makeFormatter().formatStatement('var x = 1;;'),
	throwsA(
	isA<FormatterException>()
	.having((e) => e.errors.length, 'errors.length', equals(1))
	.having(
	(e) => e.errors.first.offset,
	'errors.length.first.offset',
	equals(10),
	),
	),
	);
	});

	test('preserves initial indent', () {
	var formatter = makeFormatter(indent: 3);
	expect(
	formatter.formatStatement('if (foo) {bar;}'),
	equals(
	' if (foo) {\n'
	' bar;\n'
	' }',
	),
	);
	});

	group('line endings', () {
	test('uses given line ending', () {
	// Use zero width no-break space character as the line ending. We have
	// to use a whitespace character for the line ending as the formatter
	// will throw an error if it accidentally makes non-whitespace changes
	// as would occur if we used a non-whitespace character as the line
	// ending.
	var lineEnding = '\t';
	expect(
	makeFormatter(lineEnding: lineEnding).format('var i = 1;'),
	equals('var i = 1;\t'),
	);
	});

	test('infers \\r\\n if the first newline uses that', () {
	expect(
	makeFormatter().format('var\r\ni\n=\n1;\n'),
	equals('var i = 1;\r\n'),
	);
	});

	test('infers \\n if the first newline uses that', () {
	expect(
	makeFormatter().format('var\ni\r\n=\r\n1;\r\n'),
	equals('var i = 1;\n'),
	);
	});

	test('defaults to \\n if there are no newlines', () {
	expect(makeFormatter().format('var i =1;'), equals('var i = 1;\n'));
	});

	test('handles Windows line endings in multiline strings', () {
	expect(
	makeFormatter(lineEnding: '\r\n').formatStatement(
	' """first\r\n'
	'second\r\n'
	'third""" ;',
	),
	equals(
	'"""first\r\n'
	'second\r\n'
	'third""";',
	),
	);
	});
	});

	test('throws an UnexpectedOutputException on non-whitespace changes', () {
	// Use an invalid line ending character to ensure the formatter will
	// attempt to make non-whitespace changes.
	var formatter = makeFormatter(lineEnding: '%');
	expect(
	() => formatter.format('var i = 1;'),
	throwsA(isA<UnexpectedOutputException>()),
	);
	});
	}