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,
    pub module_explicitly_set: bool,
    pub suppress_excess_property_errors: bool,
    pub suppress_implicit_any_index_errors: bool,
}

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 // @tsz-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.

module_explicitly_set: bool

Whether the module option was explicitly set by the user (via tsconfig or CLI). When false, the module kind was computed from defaults (e.g. based on target). tsc only emits TS1202 (import assignment in ESM) when module is explicitly set.

suppress_excess_property_errors: bool

When true, suppress TS2353 (excess property) errors. This is a removed option (TS5102) but tsc still honors its suppression behavior.

suppress_implicit_any_index_errors: bool

When true, suppress TS7053 (implicit any index) errors. This is a removed option (TS5102) but tsc still honors its suppression behavior.

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.