Fix: validate the type of severity level (fixes #5499)

Currently, for example, [ "error" ] is also regarded as a valid severity. This is a totally unexpected behavior.

lib/config/config-validator.js

@@ -13,7 +13,8 @@
 
 var rules = require("../rules"),
     Environments = require("./environments"),
-    schemaValidator = require("is-my-json-valid");
+    schemaValidator = require("is-my-json-valid"),
+    util = require("util");
 
 var validators = {
     rules: Object.create(null)
@@ -83,7 +84,10 @@ function validateRuleOptions(id, options, source) {
         localOptions = [];
     }
 
-    validSeverity = (severity === 0 || severity === 1 || severity === 2 || /^(?:off|warn|error)$/i.test(severity));
+    validSeverity = (
+        severity === 0 || severity === 1 || severity === 2 ||
+        (typeof severity === "string" && /^(?:off|warn|error)$/i.test(severity))
+    );
 
     if (validateRule) {
         validateRule(localOptions);
@@ -97,7 +101,10 @@ function validateRuleOptions(id, options, source) {
 
         if (!validSeverity) {
             message.push(
-                "\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed \"", severity, "\").\n");
+                "\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed '",
+                util.inspect(severity).replace(/'/g, "\"").replace(/\n/g, ""),
+                "').\n"
+            );
         }
 
         if (validateRule && validateRule.errors) {

tests/lib/config/config-validator.js

@@ -138,7 +138,7 @@ describe("Validator", function() {
         it("should catch invalid rule options", function() {
             var fn = validator.validate.bind(null, { rules: { "mock-rule": [3, "third"] } }, "tests");
 
-            assert.throws(fn, "tests:\n\tConfiguration for rule \"mock-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed \"3\").\n\tValue \"third\" must be an enum value.\n");
+            assert.throws(fn, "tests:\n\tConfiguration for rule \"mock-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed '3').\n\tValue \"third\" must be an enum value.\n");
         });
 
         it("should allow for rules with no options", function() {
@@ -201,28 +201,34 @@ describe("Validator", function() {
 
     describe("validateRuleOptions", function() {
 
-        it("should throw for incorrect warning level", function() {
+        it("should throw for incorrect warning level number", function() {
             var fn = validator.validateRuleOptions.bind(null, "mock-rule", 3, "tests");
 
-            assert.throws(fn, "tests:\n\tConfiguration for rule \"mock-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed \"3\").\n");
+            assert.throws(fn, "tests:\n\tConfiguration for rule \"mock-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed '3').\n");
         });
 
-        it("should throw for incorrect warning level", function() {
+        it("should throw for incorrect warning level string", function() {
             var fn = validator.validateRuleOptions.bind(null, "mock-rule", "booya", "tests");
 
-            assert.throws(fn, "tests:\n\tConfiguration for rule \"mock-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed \"booya\").\n");
+            assert.throws(fn, "tests:\n\tConfiguration for rule \"mock-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed '\"booya\"').\n");
+        });
+
+        it("should throw for invalid-type warning level", function() {
+            var fn = validator.validateRuleOptions.bind(null, "mock-rule", [["error"]], "tests");
+
+            assert.throws(fn, "tests:\n\tConfiguration for rule \"mock-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed '[ \"error\" ]').\n");
         });
 
         it("should only check warning level for nonexistent rules", function() {
             var fn = validator.validateRuleOptions.bind(null, "non-existent-rule", [3, "foobar"], "tests");
 
-            assert.throws(fn, "tests:\n\tConfiguration for rule \"non-existent-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed \"3\").\n");
+            assert.throws(fn, "tests:\n\tConfiguration for rule \"non-existent-rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed '3').\n");
         });
 
         it("should only check warning level for plugin rules", function() {
             var fn = validator.validateRuleOptions.bind(null, "plugin/rule", 3, "tests");
 
-            assert.throws(fn, "tests:\n\tConfiguration for rule \"plugin/rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed \"3\").\n");
+            assert.throws(fn, "tests:\n\tConfiguration for rule \"plugin/rule\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed '3').\n");
         });
 
         it("should throw for incorrect configuration values", function() {

tests/lib/eslint.js

@@ -1701,7 +1701,7 @@ describe("eslint", function() {
             var config = { rules: {} };
 
             var fn = eslint.verify.bind(eslint, code, config, filename);
-            assert.throws(fn, "filename.js line 1:\n\tConfiguration for rule \"no-alert\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed \"true\").\n");
+            assert.throws(fn, "filename.js line 1:\n\tConfiguration for rule \"no-alert\" is invalid:\n\tSeverity should be one of the following: 0 = off, 1 = warning, 2 = error (you passed 'true').\n");
         });
     });