svelte/compiler

const VERSION: string;

function compile(
	source: string,
	options: CompileOptions
): CompileResult;

function compileModule(
	source: string,
	options: ModuleCompileOptions
): CompileResult;

function migrate(
	source: string,
	{
		filename
	}?:
		| {
				filename?: string;
		  }
		| undefined
): {
	code: string;
};

function parse(
	source: string,
	options: {
		filename?: string;
		modern: true;
	}
): AST.Root;

function parse(
	source: string,
	options?:
		| {
				filename?: string;
				modern?: false;
		  }
		| undefined
): Record<string, any>;

function preprocess(
	source: string,
	preprocessor: PreprocessorGroup | PreprocessorGroup[],
	options?:
		| {
				filename?: string;
		  }
		| undefined
): Promise<Processed>;

function walk(): never;

namespace AST {
	export interface BaseNode {
		type: string;
		start: number;
		end: number;
	}

	export interface Fragment {
		type: 'Fragment';
		nodes: Array<
			Text | Tag | ElementLike | Block | Comment
		>;
	}

	export interface Root extends BaseNode {
		type: 'Root';
		/**
		 * Inline options provided by `<svelte:options>` — these override options passed to `compile(...)`
		 */
		options: SvelteOptions | null;
		fragment: Fragment;
		/** The parsed `<style>` element, if exists */
		css: Css.StyleSheet | null;
		/** The parsed `<script>` element, if exists */
		instance: Script | null;
		/** The parsed `<script module>` element, if exists */
		module: Script | null;
	}

	export interface SvelteOptions {
		// start/end info (needed for warnings and for our Prettier plugin)
		start: number;
		end: number;
		// options
		runes?: boolean;
		immutable?: boolean;
		accessors?: boolean;
		preserveWhitespace?: boolean;
		namespace?: Namespace;
		css?: 'injected';
		customElement?: {
			tag?: string;
			shadow?: 'open' | 'none';
			props?: Record<
				string,
				{
					attribute?: string;
					reflect?: boolean;
					type?:
						| 'Array'
						| 'Boolean'
						| 'Number'
						| 'Object'
						| 'String';
				}
			>;
			/**
			 * Is of type
			 * ```ts
			 * (ceClass: new () => HTMLElement) => new () => HTMLElement
			 * ```
			 */
			extend?: ArrowFunctionExpression | Identifier;
		};
		attributes: Attribute[];
	}

	/** Static text */
	export interface Text extends BaseNode {
		type: 'Text';
		/** Text with decoded HTML entities */
		data: string;
		/** The original text, with undecoded HTML entities */
		raw: string;
	}

	/** A (possibly reactive) template expression — `{...}` */
	export interface ExpressionTag extends BaseNode {
		type: 'ExpressionTag';
		expression: Expression;
	}

	/** A (possibly reactive) HTML template expression — `{@html ...}` */
	export interface HtmlTag extends BaseNode {
		type: 'HtmlTag';
		expression: Expression;
	}

	/** An HTML comment */
	// TODO rename to disambiguate
	export interface Comment extends BaseNode {
		type: 'Comment';
		/** the contents of the comment */
		data: string;
	}

	/** A `{@const ...}` tag */
	export interface ConstTag extends BaseNode {
		type: 'ConstTag';
		declaration: VariableDeclaration & {
			declarations: [
				VariableDeclarator & {
					id: Pattern;
					init: Expression;
				}
			];
		};
	}

	/** A `{@debug ...}` tag */
	export interface DebugTag extends BaseNode {
		type: 'DebugTag';
		identifiers: Identifier[];
	}

	/** A `{@render foo(...)} tag */
	export interface RenderTag extends BaseNode {
		type: 'RenderTag';
		expression:
			| SimpleCallExpression
			| (ChainExpression & {
					expression: SimpleCallExpression;
			  });
	}

	/** An `animate:` directive */
	export interface AnimateDirective extends BaseNode {
		type: 'AnimateDirective';
		/** The 'x' in `animate:x` */
		name: string;
		/** The y in `animate:x={y}` */
		expression: null | Expression;
	}

	/** A `bind:` directive */
	export interface BindDirective extends BaseNode {
		type: 'BindDirective';
		/** The 'x' in `bind:x` */
		name: string;
		/** The y in `bind:x={y}` */
		expression: Identifier | MemberExpression;
	}

	/** A `class:` directive */
	export interface ClassDirective extends BaseNode {
		type: 'ClassDirective';
		/** The 'x' in `class:x` */
		name: 'class';
		/** The 'y' in `class:x={y}`, or the `x` in `class:x` */
		expression: Expression;
	}

	/** A `let:` directive */
	export interface LetDirective extends BaseNode {
		type: 'LetDirective';
		/** The 'x' in `let:x` */
		name: string;
		/** The 'y' in `let:x={y}` */
		expression:
			| null
			| Identifier
			| ArrayExpression
			| ObjectExpression;
	}

	/** An `on:` directive */
	export interface OnDirective extends BaseNode {
		type: 'OnDirective';
		/** The 'x' in `on:x` */
		name: string;
		/** The 'y' in `on:x={y}` */
		expression: null | Expression;
		modifiers: string[];
	}

	/** A `style:` directive */
	export interface StyleDirective extends BaseNode {
		type: 'StyleDirective';
		/** The 'x' in `style:x` */
		name: string;
		/** The 'y' in `style:x={y}` */
		value:
			| true
			| ExpressionTag
			| Array<ExpressionTag | Text>;
		modifiers: Array<'important'>;
	}

	// TODO have separate in/out/transition directives
	/** A `transition:`, `in:` or `out:` directive */
	export interface TransitionDirective extends BaseNode {
		type: 'TransitionDirective';
		/** The 'x' in `transition:x` */
		name: string;
		/** The 'y' in `transition:x={y}` */
		expression: null | Expression;
		modifiers: Array<'local' | 'global'>;
		/** True if this is a `transition:` or `in:` directive */
		intro: boolean;
		/** True if this is a `transition:` or `out:` directive */
		outro: boolean;
	}

	/** A `use:` directive */
	export interface UseDirective extends BaseNode {
		type: 'UseDirective';
		/** The 'x' in `use:x` */
		name: string;
		/** The 'y' in `use:x={y}` */
		expression: null | Expression;
	}

	interface BaseElement extends BaseNode {
		name: string;
		attributes: Array<
			Attribute | SpreadAttribute | Directive
		>;
		fragment: Fragment;
	}

	export interface Component extends BaseElement {
		type: 'Component';
	}

	export interface TitleElement extends BaseElement {
		type: 'TitleElement';
		name: 'title';
	}

	export interface SlotElement extends BaseElement {
		type: 'SlotElement';
		name: 'slot';
	}

	export interface RegularElement extends BaseElement {
		type: 'RegularElement';
	}

	export interface SvelteBody extends BaseElement {
		type: 'SvelteBody';
		name: 'svelte:body';
	}

	export interface SvelteComponent extends BaseElement {
		type: 'SvelteComponent';
		name: 'svelte:component';
		expression: Expression;
	}

	export interface SvelteDocument extends BaseElement {
		type: 'SvelteDocument';
		name: 'svelte:document';
	}

	export interface SvelteElement extends BaseElement {
		type: 'SvelteElement';
		name: 'svelte:element';
		tag: Expression;
	}

	export interface SvelteFragment extends BaseElement {
		type: 'SvelteFragment';
		name: 'svelte:fragment';
	}

	export interface SvelteHead extends BaseElement {
		type: 'SvelteHead';
		name: 'svelte:head';
	}

	/** This is only an intermediate representation while parsing, it doesn't exist in the final AST */
	export interface SvelteOptionsRaw extends BaseElement {
		type: 'SvelteOptions';
		name: 'svelte:options';
	}

	export interface SvelteSelf extends BaseElement {
		type: 'SvelteSelf';
		name: 'svelte:self';
	}

	export interface SvelteWindow extends BaseElement {
		type: 'SvelteWindow';
		name: 'svelte:window';
	}

	/** An `{#each ...}` block */
	export interface EachBlock extends BaseNode {
		type: 'EachBlock';
		expression: Expression;
		context: Pattern;
		body: Fragment;
		fallback?: Fragment;
		index?: string;
		key?: Expression;
	}

	/** An `{#if ...}` block */
	export interface IfBlock extends BaseNode {
		type: 'IfBlock';
		elseif: boolean;
		test: Expression;
		consequent: Fragment;
		alternate: Fragment | null;
	}

	/** An `{#await ...}` block */
	export interface AwaitBlock extends BaseNode {
		type: 'AwaitBlock';
		expression: Expression;
		// TODO can/should we move these inside the ThenBlock and CatchBlock?
		/** The resolved value inside the `then` block */
		value: Pattern | null;
		/** The rejection reason inside the `catch` block */
		error: Pattern | null;
		pending: Fragment | null;
		then: Fragment | null;
		catch: Fragment | null;
	}

	export interface KeyBlock extends BaseNode {
		type: 'KeyBlock';
		expression: Expression;
		fragment: Fragment;
	}

	export interface SnippetBlock extends BaseNode {
		type: 'SnippetBlock';
		expression: Identifier;
		parameters: Pattern[];
		body: Fragment;
	}

	export interface Attribute extends BaseNode {
		type: 'Attribute';
		name: string;
		/**
		 * Quoted/string values are represented by an array, even if they contain a single expression like `"{x}"`
		 */
		value:
			| true
			| ExpressionTag
			| Array<Text | ExpressionTag>;
	}

	export interface SpreadAttribute extends BaseNode {
		type: 'SpreadAttribute';
		expression: Expression;
	}

	export interface Script extends BaseNode {
		type: 'Script';
		context: 'default' | 'module';
		content: Program;
		attributes: Attribute[];
	}
}

interface CompileError extends ICompileDiagnostic {}

interface CompileOptions extends ModuleCompileOptions {…}

interface CompileResult {…}

type MarkupPreprocessor = (options: {
	/**
	 * The whole Svelte file content
	 */
	content: string;
	/**
	 * The filename of the Svelte file
	 */
	filename?: string;
}) => Processed | void | Promise<Processed | void>;

interface ModuleCompileOptions {…}

type Preprocessor = (options: {
	/**
	 * The script/style tag content
	 */
	content: string;
	/**
	 * The attributes on the script/style tag
	 */
	attributes: Record<string, string | boolean>;
	/**
	 * The whole Svelte file content
	 */
	markup: string;
	/**
	 * The filename of the Svelte file
	 */
	filename?: string;
}) => Processed | void | Promise<Processed | void>;

interface PreprocessorGroup {…}

interface Processed {…}

interface Warning extends ICompileDiagnostic {}