feat: pass file info to custom rules (#42)

* pass file info to custom rules

* add test for file info

src/lib/linting.js

@@ -105,7 +105,7 @@ class Linting extends EventEmitter {
                 // execute the rule, potentially waiting for async rules
                 // also handles catching errors from the rule
                 Promise.resolve()
-                    .then(() => rule(reporter, cheerioParsed, ast))
+                    .then(() => rule(reporter, cheerioParsed, ast, { filepath: this.path }))
                     .catch(e => reporter.exception(e))
                     .then(() => onDone(reporter));
             };

src/rules/custom.js

@@ -1,8 +1,9 @@
-const logger = require("../lib/logger")("rule:elm");
+const logger = require("../lib/logger")("rule:custom");
 
 /** @typedef {import("../lib/reporter.js")} Reporter */
 /** @typedef {import("../lib/parse.js").AST} AST */
 /** @typedef {import("../lib/parse.js").Node} Node */
+/** @typedef {{ filepath: string }} Info */
 
 /**
  * @callback CustomRule
@@ -27,10 +28,11 @@ module.exports = {
          * @param {Cheerio} $ A cheerio representation of the document
          * @param {AST} ast The underlying AST representation of the document.
          *                  This should be given to Reporter when warning/erroring with a node.
+         * @param {Info} info Info related to the current file being linted.
          */
-        return function CustomRule(reporter, $, ast) {
+        return function CustomRule(reporter, $, ast, info) {
             logger.debug("Called", config);
-            return config(reporter, $, ast);
+            return config(reporter, $, ast, info);
         };
     }
 };

test/custom.spec.js

@@ -10,7 +10,7 @@ process.on("unhandledRejection", error => {
  * ### `custom`
 
 Specifies a custom rule.
-Used as a quick-and-dirty way of adding rules when you don't want to write an 
+Used as a quick-and-dirty way of adding rules when you don't want to write an
 entire NPM package.
 
 ```javascript
@@ -99,6 +99,19 @@ describe("Rule: custom", function(){
         return testSucceeds([]);
     });
 
+    it("should provide file information", function(){
+        return testSucceeds([
+            (_reporter, _$, _ast, info) => {
+                if(!info) {
+                    throw new Error("no info provided");
+                }
+                if(!info.hasOwnProperty("filepath")) {
+                    throw new Error("no filepath provided on info");
+                }
+            }
+        ]);
+    });
+
     it("should succeed with a void function", function(){
         return testSucceeds([
             () => {}