java-best-practices

Apply Guard, Value Types, Immutability, and Naming conventions in Swift. Use when writing idiomatic Swift using guard, value types, immutability, or naming conventions. (triggers: **/*.swift, guard, let, struct, final)

Apply core coding standards, dependency injection, and configuration for Spring Boot 3. Use when applying Spring Boot 3 coding standards or configuring dependency injection. (triggers: application.properties, **/*Service.java, autowired, requiredargsconstructor, configuration-properties, slf4j)

Write PHP following best practices, PSR standards, and code quality guidelines. Use when writing PHP following PSR standards, SOLID principles, or improving code quality. (triggers: **/*.php, psr-12, camelCase, PascalCase, dry, solid)

Core patterns for robust Kotlin code including scope functions and backing properties. Use when writing idiomatic Kotlin, choosing between scope functions (let/apply/run/also/with), encapsulating mutable state with backing properties, or exposing read-only collection interfaces. (triggers: **/*.kt, apply, let, run, also, with, runCatching, backing property, MutableList, internal, private set)

Configure development tools, linting, and testing for JavaScript projects. Use when configuring ESLint, Prettier, or test runners for JavaScript projects. (triggers: .eslintrc.*, jest.config.*, package.json, eslint, prettier, jest, test, lint, build)

Modern JavaScript (ES2022+) patterns for clean, maintainable code. Use when working with modern JavaScript features like optional chaining, nullish coalescing, or ESM. (triggers: **/*.js, **/*.mjs, **/*.cjs, const, let, arrow, async, await, promise, destructuring, spread, class)

Idiomatic JavaScript patterns and conventions for maintainable code. Use when writing or refactoring JavaScript following idiomatic patterns and conventions. (triggers: **/*.js, **/*.mjs, module, import, export, error, validation)

Configure Maven, Gradle, and static analysis for Java projects. Use when setting up Java build tooling, configuring Spotless or Checkstyle, managing JDK versions with sdkman, writing Dockerfiles for Java services, or adding SpotBugs/SonarLint. (triggers: pom.xml, build.gradle, build.gradle.kts, mvnw, gradlew, .sdkmanrc, spotbugs, checkstyle, spotless, eclipse-temurin)

Testing standards using JUnit 5, AssertJ, and Mockito for Java. Use when writing or reviewing Java unit tests, setting up parameterized tests, writing integration tests with Testcontainers, or working with Mockito mocks. (triggers: **/*Test.java, **/*IT.java, @Test, @ParameterizedTest, Mockito, AssertJ, assertThat, JUnit, Testcontainers)

Modern Java 21+ standards including Records, Pattern Matching, and Virtual Threads. Use when working with Java records, sealed classes, switch expressions, text blocks, Optional, or upgrading from older Java versions. (triggers: **/*.java, pom.xml, build.gradle, record, sealed, switch, var, Optional, stream, VirtualThread, instanceof, text block)

Implement modern concurrency with Virtual Threads and Structured Concurrency in Java. Use when implementing Java Virtual Threads (Java 21), Structured Concurrency with StructuredTaskScope, CompletableFuture pipelines, or debugging race conditions. (triggers: **/*.java, Thread, Executor, synchronized, lock, CompletableFuture, StructuredTaskScope, VirtualThread, AtomicInteger, async, race condition)

Dart code quality conventions: naming, const/final/var hierarchy, single quotes, trailing commas, collection idioms, tear-offs, and import organization. Use when writing new Dart code or reviewing for style violations — wrong import style, global variables, var misuse, anonymous lambdas where tear-offs fit, or missing trailing commas. (triggers: **/*.dart, naming, convention, trailing comma, import, tear-off)