chore: add lint rules, fix script\configs

web/eslint-plugins/conventions/ascii-only.js

@@ -0,0 +1,61 @@
+// Rule: ASCII-ONLY SOURCE (scoped to test files via eslint.config.js).
+// Non-ASCII in test names and expectations hurts grep-ability and hides
+// hardcoded localized strings; intentional glyphs go to the allowChars
+// option. File-content based (not AST), one report per line.
+// Details: web/eslint-plugins/README.md.
+
+const DEFAULT_ALLOW = [];
+
+export default {
+	meta: {
+		type: "suggestion",
+		docs: {
+			description:
+				"Require ASCII-only source in scoped files (tests); exceptions go to the allowChars option.",
+			category: "Conventions",
+			recommended: false,
+		},
+		schema: [
+			{
+				type: "object",
+				properties: {
+					allowChars: {
+						type: "array",
+						items: { type: "string", minLength: 1, maxLength: 1 },
+						uniqueItems: true,
+					},
+				},
+				additionalProperties: false,
+			},
+		],
+		messages: {
+			nonAscii:
+				"Non-ASCII character {{chars}} on this line. Tests are written in plain ASCII English; keep intentional glyphs in the rule's allowChars option.",
+		},
+	},
+	create(context) {
+		const allowed = new Set(context.options[0]?.allowChars ?? DEFAULT_ALLOW);
+		return {
+			Program() {
+				const sourceCode = context.sourceCode;
+				const text = sourceCode.getText();
+				const reportedLines = new Set();
+				// eslint-disable-next-line no-control-regex -- the printable-ASCII whitelist needs explicit control escapes
+				for (const match of text.matchAll(/[^\x09\x0A\x0D\x20-\x7E]/g)) {
+					const char = match[0];
+					if (allowed.has(char)) continue;
+					const loc = sourceCode.getLocFromIndex(match.index);
+					if (reportedLines.has(loc.line)) continue;
+					reportedLines.add(loc.line);
+					context.report({
+						loc,
+						messageId: "nonAscii",
+						data: {
+							chars: `'${char}' (U+${char.codePointAt(0).toString(16).toUpperCase().padStart(4, "0")})`,
+						},
+					});
+				}
+			},
+		};
+	},
+};