chore: markdown runtime errors/warnings (#11304)

* chore: markdown runtime warnings

* on second thoughts

* start adding errors too

* lint

* centralise

Author: Rich-Harris

.prettierignore

@@ -5,6 +5,9 @@ packages/**/config/*.js
 packages/svelte/messages/**/*.md
 packages/svelte/src/compiler/errors.js
 packages/svelte/src/compiler/warnings.js
+packages/svelte/src/internal/client/errors.js
+packages/svelte/src/internal/client/warnings.js
+packages/svelte/src/internal/shared/warnings.js
 packages/svelte/tests/**/*.svelte
 packages/svelte/tests/**/_expected*
 packages/svelte/tests/**/_actual*

eslint.config.js

@@ -35,6 +35,9 @@ export default [
 			'**/tests',
 			'packages/svelte/scripts/process-messages/templates/*.js',
 			'packages/svelte/src/compiler/errors.js',
+			'packages/svelte/src/internal/client/errors.js',
+			'packages/svelte/src/internal/client/warnings.js',
+			'packages/svelte/src/internal/shared/warnings.js',
 			'packages/svelte/compiler/index.js',
 			// documentation can contain invalid examples
 			'documentation',

packages/svelte/messages/client-errors/effects.md

@@ -0,0 +1,3 @@
+## effect_update_depth_exceeded
+
+Maximum update depth exceeded. This can happen when a reactive block or effect repeatedly sets a new value. Svelte limits the number of nested updates to prevent infinite loops

packages/svelte/messages/client-errors/lifecycle.md

@@ -0,0 +1,7 @@
+## lifecycle_outside_component
+
+`%name%(...)` can only be used during component initialisation
+
+## lifecycle_legacy_only
+
+`%name%(...)` cannot be used in runes mode

packages/svelte/messages/client-warnings/warnings.md

@@ -0,0 +1,7 @@
+## lifecycle_double_unmount
+
+Tried to unmount a component that was not mounted
+
+## ownership_invalid_binding
+
+%parent% passed a value to %child% with `bind:`, but the value is owned by %owner%. Consider creating a binding between %owner% and %parent%

packages/svelte/messages/shared-warnings/warnings.md

@@ -0,0 +1,3 @@
+## dynamic_void_element_content
+
+`<svelte:element this="%tag%">` is a void element — it cannot have content

packages/svelte/scripts/process-messages/index.js

@@ -220,3 +220,7 @@ function transform(name, dest) {
 
 transform('compile-errors', 'src/compiler/errors.js');
 transform('compile-warnings', 'src/compiler/warnings.js');
+
+transform('client-warnings', 'src/internal/client/warnings.js');
+transform('client-errors', 'src/internal/client/errors.js');
+transform('shared-warnings', 'src/internal/shared/warnings.js');

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

@@ -0,0 +1,17 @@
+import { DEV } from 'esm-env';
+
+/**
+ * MESSAGE
+ * @param {string} PARAMETER
+ * @returns {never}
+ */
+export function CODE(PARAMETER) {
+	if (DEV) {
+		const error = new Error(`${'CODE'}\n${MESSAGE}`);
+		error.name = 'Svelte error';
+		throw error;
+	} else {
+		// TODO print a link to the documentation
+		throw new Error('CODE');
+	}
+}

packages/svelte/scripts/process-messages/templates/client-warnings.js

@@ -0,0 +1,17 @@
+import { DEV } from 'esm-env';
+
+var bold = 'font-weight: bold';
+var normal = 'font-weight: normal';
+
+/**
+ * MESSAGE
+ * @param {string} PARAMETER
+ */
+export function CODE(PARAMETER) {
+	if (DEV) {
+		console.warn(`%c[svelte] ${'CODE'}\n%c${MESSAGE}`, bold, normal);
+	} else {
+		// TODO print a link to the documentation
+		console.warn('CODE');
+	}
+}

packages/svelte/scripts/process-messages/templates/shared-warnings.js

@@ -0,0 +1,19 @@
+import { DEV } from 'esm-env';
+
+var bold = 'font-weight: bold';
+var normal = 'font-weight: normal';
+
+/**
+ * MESSAGE
+ * @param {boolean} trace
+ * @param {string} PARAMETER
+ */
+export function CODE(trace, PARAMETER) {
+	if (DEV) {
+		console.warn(`%c[svelte] ${'CODE'}\n%c${MESSAGE}`, bold, normal);
+		if (trace) console.trace('stack trace');
+	} else {
+		// TODO print a link to the documentation
+		console.warn('CODE');
+	}
+}