start porting warnings

packages/svelte/messages/compile-warnings/attributes.md

@@ -0,0 +1,15 @@
+## avoid_is
+
+The "is" attribute is not supported cross-browser and should be avoided
+
+## global_event_reference
+
+You are referencing globalThis.%name%. Did you forget to declare a variable with that name?
+
+## illegal_attribute_character
+
+Attributes should not contain ':' characters to prevent ambiguity with Svelte directives
+
+## invalid_html_attribute
+
+'%wrong%' is not a valid HTML attribute. Did you mean '%right%'?

packages/svelte/messages/compile-warnings/css.md

@@ -0,0 +1,3 @@
+## css_unused_selector
+
+Unused CSS selector "%name%"

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

@@ -211,3 +211,4 @@ function transform(name, dest) {
 }
 
 transform('compile-errors', 'src/compiler/errors.js');
+transform('compile-warnings', 'src/compiler/warnings.js');

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

@@ -0,0 +1,51 @@
+import { getLocator } from 'locate-character';
+
+/** @typedef {{ start?: number, end?: number }} NodeLike */
+
+// TODO no need to export these, it's temporary
+/** @type {import('#compiler').Warning[]} */
+export let warnings = [];
+/** @type {string | undefined} */
+export let filename;
+export let locator = getLocator('', { offsetLine: 1 });
+
+/**
+ * @param {{
+ *   source: string;
+ *   filename: string | undefined;
+ * }} options
+ * @returns {import('#compiler').Warning[]}
+ */
+export function reset_warnings(options) {
+	filename = options.filename;
+	locator = getLocator(options.source, { offsetLine: 1 });
+
+	return (warnings = []);
+}
+
+/**
+ *
+ * @param {null | NodeLike} node
+ * @param {string} code
+ * @param {string} message
+ */
+function w(node, code, message) {
+	// @ts-expect-error
+	if (node.ignores?.has(code)) return;
+
+	warnings.push({
+		code,
+		message,
+		filename,
+		start: node?.start !== undefined ? locator(node.start) : undefined,
+		end: node?.end !== undefined ? locator(node.end) : undefined
+	});
+}
+
+/**
+ * @param {null | NodeLike} node
+ * @param {string} PARAMETER
+ */
+export function CODE(node, PARAMETER) {
+	w(node, 'CODE', MESSAGE);
+}

packages/svelte/src/compiler/warnings.js

@@ -0,0 +1,84 @@
+/* This file is generated by scripts/process-messages.js. Do not edit! */
+
+import { getLocator } from 'locate-character';
+
+/** @typedef {{ start?: number, end?: number }} NodeLike */
+// TODO no need to export these, it's temporary
+/** @type {import('#compiler').Warning[]} */
+export let warnings = [];
+/** @type {string | undefined} */
+export let filename;
+export let locator = getLocator('', { offsetLine: 1 });
+
+/**
+ * @param {{
+ *   source: string;
+ *   filename: string | undefined;
+ * }} options
+ * @returns {import('#compiler').Warning[]}
+ */
+export function reset_warnings(options) {
+	filename = options.filename;
+	locator = getLocator(options.source, { offsetLine: 1 });
+	return warnings = [];
+}
+
+/**
+ *
+ * @param {null | NodeLike} node
+ * @param {string} code
+ * @param {string} message
+ */
+function w(node, code, message) {
+	// @ts-expect-error
+	if (node.ignores?.has(code)) return;
+
+	warnings.push({
+		code,
+		message,
+		filename,
+		start: node?.start !== undefined ? locator(node.start) : undefined,
+		end: node?.end !== undefined ? locator(node.end) : undefined
+	});
+}
+
+/**
+ * @param {null | NodeLike} node
+
+ */
+export function avoid_is(node) {
+	w(node, "avoid_is", "The \"is\" attribute is not supported cross-browser and should be avoided");
+}
+
+/**
+ * @param {null | NodeLike} node
+ * @param {string} name
+ */
+export function global_event_reference(node, name) {
+	w(node, "global_event_reference", `You are referencing globalThis.${name}. Did you forget to declare a variable with that name?`);
+}
+
+/**
+ * @param {null | NodeLike} node
+
+ */
+export function illegal_attribute_character(node) {
+	w(node, "illegal_attribute_character", "Attributes should not contain ':' characters to prevent ambiguity with Svelte directives");
+}
+
+/**
+ * @param {null | NodeLike} node
+ * @param {string} wrong
+ * @param {string} right
+ */
+export function invalid_html_attribute(node, wrong, right) {
+	w(node, "invalid_html_attribute", `'${wrong}' is not a valid HTML attribute. Did you mean '${right}'?`);
+}
+
+/**
+ * @param {null | NodeLike} node
+ * @param {string} name
+ */
+export function css_unused_selector(node, name) {
+	w(node, "css_unused_selector", `Unused CSS selector "${name}"`);
+}