Bryan Oltman
70 lines
2.1 KiB
Markdown
70 lines
2.1 KiB
Markdown
# Shorebird Dart Style Guide
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This document outlines the style guide for all Shorebird Dart code.
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This guide is a supplement to
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[Effective Dart](https://dart.dev/guides/language/effective-dart) and should be
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read in the same way. If there is a conflict between this guide and Effective
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Dart, this guide takes precedence.
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This style guide only defines rules which are not enforced via lint rules. If
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possible, prefer using lint rules to enforce style.
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## AVOID mixins
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Mixins are a powerful feature of Dart, but they make code harder to test:
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1. Mixins cannot be tested directly and must be tested through the classes they
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are mixed into.
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2. Mixins are effectively unmockable dependencies of the classes they are mixed
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into, meaning every class that uses the mixin will need to set up and mock
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the mixin's dependencies in its own tests.
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Prefer creating a new class as a `scoped` dependency instead, or adding the code
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to an existing `scoped` dependency.
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## PREFER nested `group`s for tests
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These help to make the test structure clearer and easier to read, and result in
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less duplicated code for tests that rely on the same setup.
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```dart
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// BAD
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group('myFunction', () {
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test('returns null when dep1.foo is true and dep2.bar is false', () {
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when(() => dep1.foo).thenReturn(true);
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when(() => dep2.bar).thenReturn(false);
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expect(myFunction(), isNull);
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});
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});
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// GOOD
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group('myFunction', () {
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group('when dep1.foo is true and dep2.bar is false', () {
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setUp(() {
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when(() => dep1.foo).thenReturn(true);
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when(() => dep2.bar).thenReturn(false);
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});
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test('returns null', () {
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expect(myFunction(), isNull);
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});
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});
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});
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```
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## PREFER to use multiline string literals for long strings
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This makes the string easier to read, and reduces the chance of accidentally
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including too few or too many spaces in the string.
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```dart
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// BAD
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final longString = 'This is a string longer than the eighty character '
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'limit that our lint rules enforce.';
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// GOOD
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final longString = '''This is a string longer than the eighty character limit that our lint rules enforce.'''
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```
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