Change CodeInspection public API to expose providers.

Changes getProvidersForPath to be public - allows extensions to query providers for custom linting.
Adds getProviders to allow extensions to get all providers.
Adds deregister to allow extensions to remove a provider when the extension provides a provider with the same functionality.

Author: Mark-Simulacrum

src/language/CodeInspection.js

@@ -164,6 +164,15 @@ define(function (require, exports, module) {
         return _providers[LanguageManager.getLanguageForPath(filePath).getId()];
     }
 
+    /**
+     * Returns a list of providers
+     *
+     * @return {{languageId:string, Array.<{name:string, scanFileAsync:?function(string, string):!{$.Promise}, scanFile:?function(string, string):Object}>}} providers
+     */
+    function getProviders() {
+        return _providers;
+    }
+
     /**
      * Runs a file inspection over passed file. Uses the given list of providers if specified, otherwise uses
      * the set of providers that are registered for the file's language.
@@ -468,6 +477,27 @@ define(function (require, exports, module) {
         run();  // in case a file of this type is open currently
     }
 
+    /**
+     * Deregisters a provider, given a languageId and the provider.
+     * Allows code to remove providers which provide the same functionality
+     * as the code provides
+     *
+     * @param {string} languageId
+     * @param {{name:string, scanFileAsync:?function(string, string):!{$.Promise},
+     *         scanFile:?function(string, string):?{errors:!Array, aborted:boolean}}} provider
+     *
+     * Returns false if no provider was removed.
+     */
+    function deregister(languageId, provider) {
+        if (_providers[languageId]) {
+            _.remove(_providers[languageId], function (registeredProvider) {
+                return registeredProvider.name === provider.name;
+            });
+        } else {
+            return false;
+        }
+    }
+
     /**
      * Update DocumentManager listeners.
      */
@@ -643,9 +673,12 @@ define(function (require, exports, module) {
     exports._PREF_ASYNC_TIMEOUT     = PREF_ASYNC_TIMEOUT;
 
     // Public API
-    exports.register       = register;
-    exports.Type           = Type;
-    exports.toggleEnabled  = toggleEnabled;
-    exports.inspectFile    = inspectFile;
-    exports.requestRun     = run;
+    exports.register            = register;
+    exports.deregister          = deregister;
+    exports.Type                = Type;
+    exports.toggleEnabled       = toggleEnabled;
+    exports.inspectFile         = inspectFile;
+    exports.requestRun          = run;
+    exports.getProvidersForPath = getProvidersForPath;
+    exports.getProviders        = getProviders;
 });