From 4dbcc046c8b82d2c053d761f870041b4091575da Mon Sep 17 00:00:00 2001
From: Peter Newnham <pete@blarg.co.uk>
Date: Mon, 6 Feb 2017 16:11:08 +0000
Subject: [PATCH 1/2] Fixed: ignore cache when eslint rules have changed

---
 index.js               | 21 +++++++++++++---
 test/cache.js          | 56 ++++++++++++++++++++++++++++++++++++++++++
 test/fixtures/cache.js |  7 ++++++
 3 files changed, 81 insertions(+), 3 deletions(-)
 create mode 100644 test/cache.js
 create mode 100644 test/fixtures/cache.js

diff --git a/index.js b/index.js
index 7e1c260..87c6a2f 100644
--- a/index.js
+++ b/index.js
@@ -7,6 +7,7 @@ var findCacheDir = require("find-cache-dir")
 var objectHash = require("object-hash")
 
 var engines = {}
+var rules = {}
 var cache = null
 var cachePath = null
 
@@ -28,25 +29,39 @@ function lint(input, config, webpack) {
     resourcePath = resourcePath.substr(cwd.length + 1)
   }
 
+  // get engine
+  var configHash = objectHash(config)
+  var engine = engines[configHash]
+  var rulesHash = rules[configHash]
+
   var res
   // If cache is enable and the data are the same as in the cache, just
   // use them
   if (config.cache) {
+    // just get rules hash once per engine for performance reasons
+    if (!rulesHash) {
+      rulesHash = objectHash(engine.getConfigForFile(resourcePath))
+      rules[configHash] = rulesHash
+    }
     var inputMD5 = crypto.createHash("md5").update(input).digest("hex")
-    if (cache[resourcePath] && cache[resourcePath].hash === inputMD5) {
+    if (
+      cache[resourcePath] &&
+      cache[resourcePath].hash === inputMD5 &&
+      cache[resourcePath].rules === rulesHash
+    ) {
       res = cache[resourcePath].res
     }
   }
 
   // Re-lint the text if the cache off or miss
   if (!res) {
-    var configHash = objectHash(config)
-    res = engines[configHash].executeOnText(input, resourcePath, true)
+    res = engine.executeOnText(input, resourcePath, true)
 
     // Save new results in the cache
     if (config.cache) {
       cache[resourcePath] = {
         hash: inputMD5,
+        rules: rulesHash,
         res: res,
       }
       fs.writeFileSync(cachePath, JSON.stringify(cache))
diff --git a/test/cache.js b/test/cache.js
new file mode 100644
index 0000000..2f45258
--- /dev/null
+++ b/test/cache.js
@@ -0,0 +1,56 @@
+var test = require("tape")
+var webpack = require("webpack")
+var assign = require("object-assign")
+var conf = require("./utils/conf")
+var fs = require("fs")
+
+var cacheFilePath = "./node_modules/.cache/eslint-loader/data.json"
+
+test("eslint-loader can cache results", function(t) {
+
+  // delete the require cache for eslint-loader otherwise any previously run
+  // tests will have initialised the cache as false and prevent this test
+  // from creating the cache file
+  delete require.cache[require.resolve("../index.js")]
+
+  webpack(assign({},
+    conf,
+    {
+      entry: "./test/fixtures/cache.js",
+      eslint: {
+        cache: true,
+      },
+    }
+  ),
+  function(err) {
+    if (err) {
+      throw err
+    }
+
+    fs.readFile(cacheFilePath, "utf8", function(err, contents) {
+      if (err) {
+        t.fail("expected cache file to have been created")
+      }
+      else {
+        t.pass("cache file has been created")
+
+        var contentsJson = JSON.parse(contents)
+        t.deepEqual(
+          Object.keys(contentsJson["test/fixtures/cache.js"]),
+          ["hash", "rules", "res"],
+          "cache values have been set for the linted file"
+        )
+      }
+
+      t.end()
+
+    })
+
+  })
+})
+
+// delete the cache file once tests have completed
+test("teardown", function(t) {
+  fs.unlinkSync(cacheFilePath)
+  t.end()
+})
\ No newline at end of file
diff --git a/test/fixtures/cache.js b/test/fixtures/cache.js
new file mode 100644
index 0000000..48bffcc
--- /dev/null
+++ b/test/fixtures/cache.js
@@ -0,0 +1,7 @@
+"use strict"
+
+function cacheIt() {
+  return "cache"
+}
+
+cacheIt()

From 5a22bb0c157598320efc59a7ded7e0430db339d6 Mon Sep 17 00:00:00 2001
From: Peter Newnham <pete@blarg.co.uk>
Date: Wed, 22 Feb 2017 09:16:13 +0000
Subject: [PATCH 2/2] Update cache test with new test runner

---
 test/cache.js | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/test/cache.js b/test/cache.js
index 2f45258..241f011 100644
--- a/test/cache.js
+++ b/test/cache.js
@@ -1,25 +1,18 @@
-var test = require("tape")
+var test = require("ava")
 var webpack = require("webpack")
-var assign = require("object-assign")
 var conf = require("./utils/conf")
 var fs = require("fs")
 
 var cacheFilePath = "./node_modules/.cache/eslint-loader/data.json"
 
-test("eslint-loader can cache results", function(t) {
-
-  // delete the require cache for eslint-loader otherwise any previously run
-  // tests will have initialised the cache as false and prevent this test
-  // from creating the cache file
-  delete require.cache[require.resolve("../index.js")]
-
-  webpack(assign({},
-    conf,
+test.cb("eslint-loader can cache results", function(t) {
+  t.plan(2)
+  webpack(conf(
     {
       entry: "./test/fixtures/cache.js",
-      eslint: {
-        cache: true,
-      },
+    },
+    {
+      cache: true,
     }
   ),
   function(err) {
@@ -50,7 +43,6 @@ test("eslint-loader can cache results", function(t) {
 })
 
 // delete the cache file once tests have completed
-test("teardown", function(t) {
+test.after.always("teardown", function() {
   fs.unlinkSync(cacheFilePath)
-  t.end()
 })
\ No newline at end of file