WIP: Validate rule options

docs/developer-guide/working-with-rules.md

@@ -21,6 +21,10 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    // JSON Schema for rule options goes here
+];
 ```
 
 **Important:** Rule submissions will not be accepted unless they are in this format.
@@ -132,6 +136,34 @@ Since `context.options` is just an array, you can use it to determine how many o
 
 When using options, make sure that your rule has some logic defaults in case the options are not provided.
 
+### Options Schemas
+
+Rules may export a `schema` property, which is a [JSON schema](http://json-schema.org/) format description of a rule's options which will be used by ESLint to validate configuration options and prevent invalid or unexpected inputs before they are passed to the rule in `context.options`.
+
+There are two formats for a rule's exported `schema`. The first is a full JSON Schema object describing all possible options the rule accepts, including the rule's error level as the first argument and any optional arguments thereafter.
+
+However, to simplify schema creation, rules may also export an array of schemas for each optional positional argument, and ESLint will automatically validate the required error level first. For example, the `yoda` rule accepts a primary mode argument, as well as an extra options object with named properties.
+
+```js
+// "yoda": [2, "never", { "exceptRange": true }]
+module.exports.schema = [
+    {
+        "enum": ["always", "never"]
+    },
+    {
+        "type": "object",
+        "properties": {
+            "exceptRange": {
+                "type": "boolean"
+            }
+        },
+        "additionalProperties": false
+    }
+];
+```
+
+In the preceding example, the error level is assumed to be the first argument. It is followed by the first optional argument, a string which may be either `"always"` or `"never"`. The final optional argument is an object, which may have a Boolean property named `exceptRange`.
+
 ### Getting the Source
 
 If your rule needs to get the actual JavaScript source to work with, then use the `context.getSource()` method. This method works as follows:
@@ -191,13 +223,14 @@ The basic pattern for a rule unit test file is:
 //------------------------------------------------------------------------------
 
 var eslint = require("../../../lib/eslint"),
+    validate = require("../../../lib/validate-options"),
     ESLintTester = require("eslint-tester");
 
 //------------------------------------------------------------------------------
 // Tests
 //------------------------------------------------------------------------------
 
-var eslintTester = new ESLintTester(eslint);
+var eslintTester = new ESLintTester(eslint, validate);
 eslintTester.addRuleTest("lib/rules/block-scoped-var", {
 
     // Examples of code that should not trigger the rule

lib/cli-engine.js

@@ -27,7 +27,8 @@ var fs = require("fs"),
     traverse = require("./util/traverse"),
     IgnoredPaths = require("./ignored-paths"),
     Config = require("./config"),
-    util = require("./util");
+    util = require("./util"),
+    validate = require("./validate-options");
 
 //------------------------------------------------------------------------------
 // Typedefs
@@ -285,6 +286,10 @@ function CLIEngine(options) {
             rules.load(rulesdir);
         });
     }
+
+    Object.keys(this.options.rules || {}).forEach(function(name) {
+        validate(name, this.options.rules[name], "CLI");
+    }.bind(this));
 }
 
 CLIEngine.prototype = {

lib/config.js

@@ -11,17 +11,18 @@
 // Requirements
 //------------------------------------------------------------------------------
 
-var fs = require("fs"),
-    path = require("path"),
+var assign = require("object-assign"),
+    debug = require("debug"),
     environments = require("../conf/environments"),
-    util = require("./util"),
     FileFinder = require("./file-finder"),
+    fs = require("fs"),
+    isAbsolutePath = require("path-is-absolute"),
+    path = require("path"),
     stripComments = require("strip-json-comments"),
-    assign = require("object-assign"),
-    debug = require("debug"),
-    yaml = require("js-yaml"),
     userHome = require("user-home"),
-    isAbsolutePath = require("path-is-absolute");
+    util = require("./util"),
+    validate = require("./validate-options"),
+    yaml = require("js-yaml");
 
 //------------------------------------------------------------------------------
 // Constants
@@ -86,6 +87,12 @@ function loadConfig(filePath) {
             config = require(filePath);
         }
 
+        if (config.rules) {
+            Object.keys(config.rules).forEach(function (name) {
+                validate(name, config.rules[name], filePath);
+            });
+        }
+
         // If an `extends` property is defined, it represents a configuration file to use as
         // a "parent". Load the referenced file and merge the configuration recursively.
         if (config.extends) {

lib/eslint.js

@@ -8,17 +8,18 @@
 // Requirements
 //------------------------------------------------------------------------------
 
-var estraverse = require("estraverse-fb"),
-    escope = require("escope"),
+var assign = require("object-assign"),
+    createTokenStore = require("./token-store.js"),
     environments = require("../conf/environments"),
-    assign = require("object-assign"),
-    rules = require("./rules"),
-    util = require("./util"),
+    escapeRegExp = require("escape-string-regexp"),
+    escope = require("escope"),
+    estraverse = require("estraverse-fb"),
+    EventEmitter = require("events").EventEmitter,
     RuleContext = require("./rule-context"),
+    rules = require("./rules"),
     timing = require("./timing"),
-    createTokenStore = require("./token-store.js"),
-    EventEmitter = require("events").EventEmitter,
-    escapeRegExp = require("escape-string-regexp");
+    util = require("./util"),
+    validate = require("./validate-options");
 
 //------------------------------------------------------------------------------
 // Helpers
@@ -238,13 +239,14 @@ function enableReporting(reportingConfig, start, rulesToEnable) {
  * Parses comments in file to extract file-specific config of rules, globals
  * and environments and merges them with global config; also code blocks
  * where reporting is disabled or enabled and merges them with reporting config.
+ * @param {string} filename The file being checked.
  * @param {ASTNode} ast The top node of the AST.
  * @param {Object} config The existing configuration data.
  * @param {Object[]} reportingConfig The existing reporting configuration data.
  * @param {Object[]} messages The messages queue.
  * @returns {void}
  */
-function modifyConfigsFromComments(ast, config, reportingConfig, messages) {
+function modifyConfigsFromComments(filename, ast, config, reportingConfig, messages) {
 
     var commentConfig = {
         astGlobals: {},
@@ -285,6 +287,7 @@ function modifyConfigsFromComments(ast, config, reportingConfig, messages) {
                         Object.keys(items).forEach(function(name) {
                             var ruleValue = items[name];
                             if (typeof ruleValue === "number" || (Array.isArray(ruleValue) && typeof ruleValue[0] === "number")) {
+                                validate(name, ruleValue, filename + " line " + comment.loc.start.line);
                                 commentRules[name] = ruleValue;
                             }
                         });
@@ -613,7 +616,7 @@ module.exports = (function() {
             currentAST = ast;
 
             // parse global comments and modify config
-            modifyConfigsFromComments(ast, config, reportingConfig, messages);
+            modifyConfigsFromComments(filename, ast, config, reportingConfig, messages);
 
             // enable appropriate rules
             Object.keys(config.rules).filter(function(key) {

lib/rules/block-scoped-var.js

@@ -316,3 +316,5 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [];

lib/rules/brace-style.js

@@ -211,3 +211,18 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "enum": ["1tbs", "stroustrup"]
+    },
+    {
+        "type": "object",
+        "properties": {
+            "allowSingleLine": {
+                "type": "boolean"
+            }
+        },
+        "additionalProperties": false
+    }
+];

lib/rules/camelcase.js

@@ -97,3 +97,15 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "type": "object",
+        "properties": {
+            "properties": {
+                "enum": ["always", "never"]
+            }
+        },
+        "additionalProperties": false
+    }
+];

lib/rules/comma-dangle.js

@@ -56,3 +56,9 @@ module.exports = function (context) {
         "ArrayExpression": checkForTrailingComma
     };
 };
+
+module.exports.schema = [
+    {
+        "enum": ["always", "always-multiline", "never"]
+    }
+];

lib/rules/comma-spacing.js

@@ -157,3 +157,18 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "type": "object",
+        "properties": {
+            "before": {
+                "type": "boolean"
+            },
+            "after": {
+                "type": "boolean"
+            }
+        },
+        "additionalProperties": false
+    }
+];

lib/rules/comma-style.js

@@ -175,3 +175,21 @@ module.exports = function(context) {
 
     return nodes;
 };
+
+module.exports.schema = [
+    {
+        "enum": ["first", "last"]
+    },
+    {
+        "type": "object",
+        "properties": {
+            "exceptions": {
+                "type": "object",
+                "additionalProperties": {
+                    "type": "boolean"
+                }
+            }
+        },
+        "additionalProperties": false
+    }
+];

lib/rules/complexity.js

@@ -86,3 +86,9 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "type": "integer"
+    }
+];

lib/rules/consistent-return.js

@@ -71,3 +71,5 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [];

lib/rules/consistent-this.js

@@ -106,3 +106,9 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "type": "string"
+    }
+];

lib/rules/curly.js

@@ -101,3 +101,9 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "enum": ["all", "multi", "multi-line"]
+    }
+];

lib/rules/default-case.js

@@ -62,3 +62,5 @@ module.exports = function(context) {
         }
     };
 };
+
+module.exports.schema = [];

lib/rules/dot-notation.js

@@ -102,3 +102,18 @@ module.exports = function(context) {
         }
     };
 };
+
+module.exports.schema = [
+    {
+        "type": "object",
+        "properties": {
+            "allowKeywords": {
+                "type": "boolean"
+            },
+            "allowPattern": {
+                "type": "string"
+            }
+        },
+        "additionalProperties": false
+    }
+];

lib/rules/eol-last.js

@@ -34,3 +34,5 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [];

lib/rules/eqeqeq.js

@@ -88,3 +88,9 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "enum": ["smart", "allow-null"]
+    }
+];

lib/rules/func-names.js

@@ -41,3 +41,5 @@ module.exports = function(context) {
         }
     };
 };
+
+module.exports.schema = [];

lib/rules/func-style.js

@@ -41,3 +41,9 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "enum": ["declaration", "expression"]
+    }
+];

lib/rules/generator-star-spacing.js

@@ -79,3 +79,9 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "enum": ["before", "after", "both", "neither"]
+    }
+];

lib/rules/generator-star.js

@@ -68,3 +68,9 @@ module.exports = function(context) {
     };
 
 };
+
+module.exports.schema = [
+    {
+        "enum": ["start", "middle", "end"]
+    }
+];

lib/rules/global-strict.js

@@ -41,3 +41,9 @@ module.exports = function(context) {
     }
 
 };
+
+module.exports.schema = [
+    {
+        "enum": ["always", "never"]
+    }
+];