Struct CheckerOptions 

pub struct CheckerOptions {

    pub strict: bool,
    pub no_implicit_any: bool,
    pub no_implicit_returns: bool,
    pub strict_null_checks: bool,
    pub strict_function_types: bool,
    pub strict_property_initialization: bool,
    pub no_implicit_this: bool,
    pub use_unknown_in_catch_variables: bool,
    pub isolated_modules: bool,
    pub no_unchecked_indexed_access: bool,
    pub strict_bind_call_apply: bool,
    pub exact_optional_property_types: bool,
    pub no_lib: bool,
    pub no_types_and_symbols: bool,
    pub target: ScriptTarget,
    pub module: ModuleKind,
    pub es_module_interop: bool,
    pub allow_synthetic_default_imports: bool,
    pub allow_unreachable_code: Option<bool>,
    pub no_property_access_from_index_signature: bool,
    pub sound_mode: bool,
    pub experimental_decorators: bool,
    pub no_unused_locals: bool,
    pub no_unused_parameters: bool,
    pub always_strict: bool,
    pub resolve_json_module: bool,
    pub check_js: bool,
    pub no_resolve: bool,
    pub no_unchecked_side_effect_imports: bool,
    pub no_implicit_override: bool,
    pub jsx_factory: String,
    pub jsx_fragment_factory: String,
    pub jsx_mode: JsxMode,
}

Compiler options for type checking.

Fields

strict: bool

no_implicit_any: bool

no_implicit_returns: bool

strict_null_checks: bool

strict_function_types: bool

strict_property_initialization: bool

no_implicit_this: bool

use_unknown_in_catch_variables: bool

isolated_modules: bool

no_unchecked_indexed_access: bool

When true, indexed access with index signatures adds | undefined to the type

strict_bind_call_apply: bool

When true, checking bind/call/apply uses strict function signatures

exact_optional_property_types: bool

When true, optional properties are treated as exactly T | undefined not T | undefined | missing

no_lib: bool

When true, no library files (including lib.d.ts) are included. This corresponds to the –noLib compiler flag. TS2318 errors are emitted when referencing global types with this option enabled.

no_types_and_symbols: bool

When true, do not automatically inject built-in type declarations. This corresponds to the –noTypesAndSymbols compiler flag. Prevents loading default lib.d.ts files which provide types like Array, Object, etc.

target: ScriptTarget

Target ECMAScript version (ES3, ES5, ES2015, ES2016, etc.) Controls which built-in types are available (e.g., Promise requires ES2015) Defaults to ES3 for maximum compatibility

module: ModuleKind

Module kind (None, CommonJS, ES2015, ES2020, ES2022, ESNext, etc.) Controls which module system is being targeted (affects import/export syntax validity)

es_module_interop: bool

Emit additional JavaScript to ease support for importing CommonJS modules. When true, synthesizes default exports for CommonJS modules.

allow_synthetic_default_imports: bool

Allow ‘import x from y’ when a module doesn’t have a default export. Implied by esModuleInterop.

allow_unreachable_code: Option<bool>

Controls reporting of unreachable code (TS7027).

• None (default): tsc emits TS7027 as a suggestion, not an error
• Some(false): tsc emits TS7027 as an error
• Some(true): tsc does not emit TS7027 at all

no_property_access_from_index_signature: bool

When true, require bracket notation for index signature property access (TS4111).

sound_mode: bool

When true, enable Sound Mode for stricter type checking beyond TypeScript’s defaults. Sound Mode catches common unsoundness issues like:

• Mutable array covariance (TS9002)
• Method parameter bivariance (TS9003)
• any escapes (TS9004)
• Excess properties via sticky freshness (TS9001)

Activated via: --sound CLI flag or // @ts-sound pragma

experimental_decorators: bool

When true, enables experimental support for decorators (legacy decorators). This is required for the @experimentalDecorators flag. When decorators are used, TypedPropertyDescriptor must be available.

no_unused_locals: bool

When true, report errors for unused local variables (TS6133).

no_unused_parameters: bool

When true, report errors for unused function parameters (TS6133).

always_strict: bool

When true, parse in strict mode and emit “use strict” for each source file. Enables TS1100 for invalid use of ‘arguments’ in strict mode.

resolve_json_module: bool

When true, allows importing JSON files with .json extension. When false, importing JSON files emits TS2732 suggesting to enable this flag.

check_js: bool

When true, enable type checking in JavaScript files. This corresponds to the –checkJs compiler flag. With checkJs enabled, noImplicitAny and other type errors apply to .js files.

no_resolve: bool

When true, disable dependency expansion from imports and triple-slash references.

no_unchecked_side_effect_imports: bool

When true, check side-effect imports for module resolution errors (TS2882).

no_implicit_override: bool

When true, require ‘override’ modifier on members that override base class members (TS4114).

jsx_factory: String

JSX factory function (e.g. React.createElement)

jsx_fragment_factory: String

JSX fragment factory function (e.g. React.Fragment)

jsx_mode: JsxMode

JSX emit mode (preserve, react, react-jsx, react-jsxdev, react-native). Only “react” (classic transform) requires the factory to be in scope.

Implementations

impl CheckerOptions

pub const fn apply_strict_defaults(self) -> CheckerOptions

Apply TypeScript’s --strict defaults to individual strict flags. In tsc, enabling strict turns on the strict family unless explicitly disabled. We mirror that behavior by OR-ing the per-flag booleans with strict.

Trait Implementations

impl Clone for CheckerOptions

fn clone(&self) -> CheckerOptions

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CheckerOptions

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for CheckerOptions

fn default() -> CheckerOptions

Returns the “default value” for a type.