Chore: avoid monkeypatching Linter instances in RuleTester (#9276)

eslint · Sep 11, 2017 · 61f1093 · 61f1093
1 parent 28929cb
commit 61f1093
Showing 1 changed file with 16 additions and 30 deletions.
diff --git a/lib/testers/rule-tester.js b/lib/testers/rule-tester.js
@@ -307,7 +307,17 @@ class RuleTester {
                 config.rules[ruleName] = 1;
             }
 
-            linter.defineRule(ruleName, rule);
+            linter.defineRule(ruleName, Object.assign({}, rule, {
+
+                // Create a wrapper rule that freezes the `context` properties.
+                create(context) {
+                    freezeDeeply(context.options);
+                    freezeDeeply(context.settings);
+                    freezeDeeply(context.parserOptions);
+
+                    return (typeof rule === "function" ? rule : rule.create)(context);
+                }
+            }));
 
             const schema = validator.getRuleOptionsSchema(rule);
 
@@ -341,35 +351,11 @@ class RuleTester {
                 }
             }));
 
-            // Freezes rule-context properties.
-            const originalGet = linter.rules.get;
-
-            try {
-                linter.rules.get = function(ruleId) {
-                    const originalRule = originalGet.call(linter.rules, ruleId);
-
-                    return {
-                        meta: originalRule.meta,
-                        create(context) {
-                            Object.freeze(context);
-                            freezeDeeply(context.options);
-                            freezeDeeply(context.settings);
-                            freezeDeeply(context.parserOptions);
-
-                            return originalRule.create(context);
-                        }
-                    };
-
-                };
-
-                return {
-                    messages: linter.verify(code, config, filename, true),
-                    beforeAST,
-                    afterAST: cloneDeeplyExcludesParent(afterAST)
-                };
-            } finally {
-                linter.rules.get = originalGet;
-            }
+            return {
+                messages: linter.verify(code, config, filename, true),
+                beforeAST,
+                afterAST: cloneDeeplyExcludesParent(afterAST)
+            };
         }
 
         /**