feat: rule no-unsafe-values

Fixes eslint#29

src/rules/no-unsafe-values.js

@@ -0,0 +1,54 @@
+/**
+ * @fileoverview Rule to unsafe values in JSON.
+ * @author Bradley Meck Farias
+ */
+
+export default {
+ meta: {
+ type: "problem",
+
+ docs: {
+ description: "Disallow JSON values that are unsafe for interchange",
+ },
+
+ messages: {
+ unsafeNumber: "Number outside safe range found.",
+ loneSurrogate: "Lone surrogate found.",
+ },
+ },
+
+ create(context) {
+ return {
+ Number(node) {
+ if (Number.isFinite(node.value) !== true) {
+ context.report({
+ loc: node.loc,
+ messageId: "unsafeNumber",
+ });
+ }
+ },
+ String(node) {
+ if (node.value.isWellFormed) {
+ if (node.value.isWellFormed()) {
+ return;
+ }
+ }
+ // match any high surrogate and, if it exists, a paired low surrogate
+ // match any low surrogate not already matched
+ const surrogatePattern =
+ /[\uD800-\uDBFF][\uDC00-\uDFFF]?|[\uDC00-\uDFFF]/gu;
+ let match = surrogatePattern.exec(node.value);
+ while (match) {
+ // only need to report non-paired surrogates
+ if (match[0].length < 2) {
+ context.report({
+ loc: node.loc,
+ messageId: "loneSurrogate",
+ });
+ }
+ match = surrogatePattern.exec(node.value);
+ }
+ },
+ };
+ },
+};

tests/rules/no-unsafe-values.test.js

@@ -0,0 +1,125 @@
+/**
+ * @fileoverview Tests for no-empty-keys rule.
+ * @author Bradley Meck Farias
+ */
+
+//------------------------------------------------------------------------------
+// Imports
+//------------------------------------------------------------------------------
+
+import rule from "../../src/rules/no-unsafe-values.js";
+import json from "../../src/index.js";
+import { RuleTester } from "eslint";
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester({
+ plugins: {
+ json,
+ },
+ language: "json/json",
+});
+
+ruleTester.run("no-unsafe-values", rule, {
+ valid: [
+ "123",
+ {
+ code: "1234",
+ language: "json/json5",
+ },
+ {
+ code: "12345",
+ language: "json/json5",
+ },
+ '"🔥"',
+ '"\\ud83d\\udd25"',
+ ],
+ invalid: [
+ {
+ code: "2e308",
+ errors: [
+ {
+ messageId: "unsafeNumber",
+ line: 1,
+ column: 1,
+ endLine: 1,
+ endColumn: 6,
+ },
+ ],
+ },
+ {
+ code: "-2e308",
+ errors: [
+ {
+ messageId: "unsafeNumber",
+ line: 1,
+ column: 1,
+ endLine: 1,
+ endColumn: 7,
+ },
+ ],
+ },
+ {
+ code: '"\ud83d"',
+ errors: [
+ {
+ messageId: "loneSurrogate",
+ line: 1,
+ column: 1,
+ endLine: 1,
+ endColumn: 4,
+ },
+ ],
+ },
+ {
+ code: '"\\ud83d"',
+ errors: [
+ {
+ messageId: "loneSurrogate",
+ line: 1,
+ column: 1,
+ endLine: 1,
+ endColumn: 9,
+ },
+ ],
+ },
+ {
+ code: '"\udd25"',
+ errors: [
+ {
+ messageId: "loneSurrogate",
+ line: 1,
+ column: 1,
+ endLine: 1,
+ endColumn: 4,
+ },
+ ],
+ },
+ {
+ code: '"\\udd25"',
+ errors: [
+ {
+ messageId: "loneSurrogate",
+ line: 1,
+ column: 1,
+ endLine: 1,
+ endColumn: 9,
+ },
+ ],
+ },
+ {
+ code: '"\ud83d\ud83d"',
+ errors: [
+ {
+ messageId: "loneSurrogate",
+ line: 1,
+ column: 1,
+ endLine: 1,
+ endColumn: 5,
+ },
+ ],
+ },
+ ],
+});