Google TypeScript style guide for writing clean, consistent, type-safe code. This skill should be used when writing, reviewing, or refactoring TypeScript code. Triggers on TypeScript files, type annotations, module imports, class design, and code style decisions.

Google TypeScript Best Practices Comprehensive TypeScript style guide based on Google's internal standards, designed for AI agents and LLMs. Contains 45 rules across 8 categories, prioritized by impact to guide automated refactoring and code generation. When to Apply Reference these guidelines when: Writing new TypeScript code Organizing modules and imports Designing type annotations and interfaces Creating classes and functions Reviewing code for style consistency Refactoring existing TypeScript code Rule Categories by Priority Priority Category Impact Prefix 1 Module Organization CRITICAL module 2 Type Safety CRITICAL types 3 Class Design HIGH class 4 Function Patterns HIGH func 5 Control Flow MEDIUM HIGH control 6 Error Handling MEDIUM error 7 Naming & Style MEDIUM naming 8 Literals & Coercion LOW MEDIUM literal Quick Reference 1. Module Organization (CRITICAL) [ module named exports ](references/module named exports.md) Use named exports over default exports [ module no mutable exports ](references/module no mutable exports.md) Avoid mutable exports [ module es6 modules ](references/module es6 modules.md) Use ES6 modules exclusively [ module no namespaces ](references/module no namespaces.md) Avoid TypeScript namespaces [ module import paths ](references/module import paths.md) Use relative paths for project imports [ module import type ](references/module import type.md) Use import type for type only imports [ module export api surface ](references/module export api surface.md) Minimize exported API surface 2. Type Safety (CRITICAL) [ types no any ](references/types no any.md) Never use the any type [ types prefer interfaces ](references/types prefer interfaces.md) Prefer interfaces over type aliases for objects [ types explicit structural ](references/types explicit structural.md) Explicitly annotate structural types [ types nullable patterns ](references/types nullable patterns.md) Handle nullable types correctly [ types array syntax ](references/types array syntax.md) Use consistent array type syntax [ types no wrapper types ](references/types no wrapper types.md) Never use wrapper object types [ types prefer map set ](references/types prefer map set.md) Prefer Map and Set over index signatures [ types no empty object ](references/types no empty object.md) Avoid empty object type 3. Class Design (HIGH) [ class parameter properties ](references/class parameter properties.md) Use parameter properties for constructor assignment [ class readonly properties ](references/class readonly properties.md) Mark properties readonly when never reassigned [ class no private fields ](references/class no private fields.md) Use TypeScript private over private fields [ class no static containers ](references/class no static containers.md) Avoid container classes with only static members [ class constructor parens ](references/class constructor parens.md) Always use parentheses in constructor calls [ class no prototype manipulation ](references/class no prototype manipulation.md) Never manipulate prototypes directly 4. Function Patterns (HIGH) [ func declarations over expressions ](references/func declarations over expressions.md) Prefer function declarations over expressions [ func arrow concise bodies ](references/func arrow concise bodies.md) Use concise arrow function bodies appropriately [ func avoid this rebinding ](references/func avoid this rebinding.md) Avoid rebinding this [ func rest parameters ](references/func rest parameters.md) Use rest parameters over arguments [ func generator syntax ](references/func generator syntax.md) Use correct generator function syntax [ func default parameters ](references/func default parameters.md) Use default parameters sparingly 5. Control Flow (MEDIUM HIGH) [ control always use braces ](references/control always use braces.md) Always use braces for control structures [ control triple equals ](references/control triple equals.md) Always use triple equals [ control for of iteration ](references/control for of iteration.md) Prefer for of over for in for arrays [ control switch default ](references/control switch default.md) Always include default case in switch [ control no assignment in condition ](references/control no assignment in condition.md) Avoid assignment in conditional expressions 6. Error Handling (MEDIUM) [ error throw errors ](references/error throw errors.md) Always throw Error instances [ error catch unknown ](references/error catch unknown.md) Type catch clause variables as unknown [ error empty catch comments ](references/error empty catch comments.md) Document empty catch blocks [ error avoid assertions ](references/error avoid assertions.md) Avoid type and non null assertions 7. Naming & Style (MEDIUM) [ naming identifier styles ](references/naming identifier styles.md) Use correct identifier naming styles [ naming descriptive names ](references/naming descriptive names.md) Use descriptive names [ naming no decorative underscores ](references/naming no decorative underscores.md) Avoid decorative underscores [ naming no interface prefix ](references/naming no interface prefix.md) No I prefix for interfaces [ naming constants ](references/naming constants.md) Use CONSTANT CASE for true constants 8. Literals & Coercion (LOW MEDIUM) [ literal single quotes ](references/literal single quotes.md) Use single quotes for strings [ literal number formats ](references/literal number formats.md) Use correct number literal formats [ literal explicit coercion ](references/literal explicit coercion.md) Use explicit type coercion [ literal array constructor ](references/literal array constructor.md) Avoid Array constructor How to Use Read individual reference files for detailed explanations and code examples: [Section definitions](references/ sections.md) Category structure and impact levels [Rule template](assets/templates/ template.md) Template for adding new rules Reference Files File Description [AGENTS.md](AGENTS.md) Complete compiled guide with all rules [references/ sections.md](references/ sections.md) Category definitions and ordering [assets/templates/ template.md](assets/templates/ template.md) Template for new rules [metadata.json](metadata.json) Version and reference information

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