fix: expose CompileError interface, not class (#12255)

* chore: refactor CompileError stuff

* changeset

Author: Rich-Harris

.changeset/good-rice-tap.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+breaking: expose `CompileError` interface, not class

packages/svelte/scripts/process-messages/templates/compile-errors.js

@@ -1,21 +1,20 @@
+/** @import { Location } from 'locate-character' */
 import * as state from './state.js';
 
 /** @typedef {{ start?: number, end?: number }} NodeLike */
 
-// interface is duplicated between here (used internally) and ./interfaces.js
-// (exposed publicly), and I'm not sure how to avoid that
-export class CompileError extends Error {
+export class InternalCompileError extends Error {
 	name = 'CompileError';
 
 	filename = state.filename;
 
-	/** @type {import('#compiler').CompileError['position']} */
+	/** @type {[number, number] | undefined} */
 	position = undefined;
 
-	/** @type {import('#compiler').CompileError['start']} */
+	/** @type {Location | undefined} */
 	start = undefined;
 
-	/** @type {import('#compiler').CompileError['end']} */
+	/** @type {Location | undefined} */
 	end = undefined;
 
 	/**
@@ -63,7 +62,7 @@ function e(node, code, message) {
 	const start = typeof node === 'number' ? node : node?.start;
 	const end = typeof node === 'number' ? node : node?.end;
 
-	throw new CompileError(
+	throw new InternalCompileError(
 		code,
 		message,
 		start !== undefined && end !== undefined ? [start, end] : undefined

packages/svelte/src/compiler/errors.js

@@ -1,18 +1,17 @@
 /* This file is generated by scripts/process-messages/index.js. Do not edit! */
 
+/** @import { Location } from 'locate-character' */
 import * as state from './state.js';
 
 /** @typedef {{ start?: number, end?: number }} NodeLike */
-// interface is duplicated between here (used internally) and ./interfaces.js
-// (exposed publicly), and I'm not sure how to avoid that
-export class CompileError extends Error {
+export class InternalCompileError extends Error {
 	name = 'CompileError';
 	filename = state.filename;
-	/** @type {import('#compiler').CompileError['position']} */
+	/** @type {[number, number] | undefined} */
 	position = undefined;
-	/** @type {import('#compiler').CompileError['start']} */
+	/** @type {Location | undefined} */
 	start = undefined;
-	/** @type {import('#compiler').CompileError['end']} */
+	/** @type {Location | undefined} */
 	end = undefined;
 
 	/**
@@ -59,7 +58,7 @@ function e(node, code, message) {
 	const start = typeof node === 'number' ? node : node?.start;
 	const end = typeof node === 'number' ? node : node?.end;
 
-	throw new CompileError(code, message, start !== undefined && end !== undefined ? [start, end] : undefined);
+	throw new InternalCompileError(code, message, start !== undefined && end !== undefined ? [start, end] : undefined);
 }
 
 /**

packages/svelte/src/compiler/index.js

@@ -139,6 +139,5 @@ export function walk() {
 	);
 }
 
-export { CompileError } from './errors.js';
 export { VERSION } from '../version.js';
 export { migrate } from './migrate/index.js';

packages/svelte/src/compiler/public.d.ts

@@ -5,4 +5,10 @@ export type {
 	PreprocessorGroup,
 	Processed
 } from './preprocess/public';
-export type { CompileOptions, ModuleCompileOptions, CompileResult, Warning } from './types/index';
+export type {
+	CompileError,
+	CompileOptions,
+	ModuleCompileOptions,
+	CompileResult,
+	Warning
+} from './types/index';

packages/svelte/src/compiler/types/index.d.ts

@@ -12,6 +12,7 @@ import type { Context } from 'zimmerframe';
 import type { Scope } from '../phases/scope.js';
 import type { Css } from './css.js';
 import type { EachBlock, Namespace, SvelteNode, SvelteOptions } from './template.js';
+import type { InternalCompileError } from '../errors.js';
 
 /** The return value of `compile` from `svelte/compiler` */
 export interface CompileResult {
@@ -59,13 +60,7 @@ export interface Warning {
 	filename?: string;
 }
 
-export interface CompileError extends Error {
-	code: string;
-	filename?: string;
-	position?: [number, number];
-	start?: Location;
-	end?: Location;
-}
+export interface CompileError extends InternalCompileError {}
 
 export type CssHashGetter = (args: {
 	name: string;

packages/svelte/types/index.d.ts

@@ -725,13 +725,7 @@ declare module 'svelte/compiler' {
 		filename?: string;
 	}
 
-	interface CompileError_1 extends Error {
-		code: string;
-		filename?: string;
-		position?: [number, number];
-		start?: Location;
-		end?: Location;
-	}
+	interface CompileError extends InternalCompileError {}
 
 	type CssHashGetter = (args: {
 		name: string;
@@ -1206,18 +1200,6 @@ declare module 'svelte/compiler' {
 	function preprocess(source: string, preprocessor: PreprocessorGroup | PreprocessorGroup[], options?: {
 		filename?: string;
 	} | undefined): Promise<Processed>;
-	class CompileError extends Error {
-		
-		constructor(code: string, message: string, position: [number, number] | undefined);
-		filename: string | undefined;
-		
-		position: CompileError_1["position"];
-		
-		start: CompileError_1["start"];
-		
-		end: CompileError_1["end"];
-		code: string;
-	}
 	/**
 	 * The current version, as set in package.json.
 	 *
@@ -1902,8 +1884,20 @@ declare module 'svelte/compiler' {
 		content: Program;
 		attributes: Attribute[];
 	}
+	class InternalCompileError extends Error {
+		
+		constructor(code: string, message: string, position: [number, number] | undefined);
+		filename: string | undefined;
+		
+		position: [number, number] | undefined;
+		
+		start: Location | undefined;
+		
+		end: Location | undefined;
+		code: string;
+	}
 
-	export { MarkupPreprocessor, Preprocessor, PreprocessorGroup, Processed, CompileOptions, ModuleCompileOptions, CompileResult, Warning, compile, compileModule, parse, walk, preprocess, CompileError, VERSION, migrate };
+	export { MarkupPreprocessor, Preprocessor, PreprocessorGroup, Processed, CompileError, CompileOptions, ModuleCompileOptions, CompileResult, Warning, compile, compileModule, parse, walk, preprocess, VERSION, migrate };
 }
 
 declare module 'svelte/easing' {