Fix: eslint.verify should not mutate config argument (fixes #8329) (#…

…8334)
eslint · Mar 28, 2017 · 3146167 · 3146167
1 parent 927de90
commit 3146167
Show file tree

Hide file tree

Showing 2 changed files with 16 additions and 5 deletions.
diff --git a/lib/eslint.js b/lib/eslint.js
@@ -778,17 +778,18 @@ module.exports = (function() {
         // search and apply "eslint-env *".
         const envInFile = findEslintEnv(text || textOrSourceCode.text);
 
+        config = Object.assign({}, config);
+
         if (envInFile) {
-            if (!config || !config.env) {
-                config = Object.assign({}, config || {}, { env: envInFile });
-            } else {
-                config = Object.assign({}, config);
+            if (config.env) {
                 config.env = Object.assign({}, config.env, envInFile);
+            } else {
+                config.env = envInFile;
             }
         }
 
         // process initial config to make it safe to extend
-        config = prepareConfig(config || {});
+        config = prepareConfig(config);
 
         // only do this for text
         if (text !== null) {

diff --git a/tests/lib/eslint.js b/tests/lib/eslint.js
@@ -3425,6 +3425,16 @@ describe("eslint", () => {
 
             assert(result.length === 0);
         });
+
+
+        it("should not modify config object passed as argument", () => {
+            const config = {};
+
+            Object.freeze(config);
+            assert.doesNotThrow(() => {
+                eslint.verify("var foo", config);
+            });
+        });
     });
 
     describe("Variables and references", () => {