From fc5455e4f9849660b48bb69d10f01e1746ef588d Mon Sep 17 00:00:00 2001
From: Sean <sean@albinodrought.com>
Date: Tue, 13 Sep 2022 20:46:06 -0700
Subject: [PATCH] feat(7): replace FormData objects with k-v map in object-hash
 replacer

---
 README.md                 | 18 +++++++++
 src/cachios.js            | 22 ++++++++++-
 tests/getReplaced.spec.js | 79 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 118 insertions(+), 1 deletion(-)
 create mode 100644 tests/getReplaced.spec.js

diff --git a/README.md b/README.md
index 77a0b2a..c09713c 100644
--- a/README.md
+++ b/README.md
@@ -292,6 +292,24 @@ cachios.getCacheIdentifier = function (config) {
 };
 ```
 
+### Custom object-hash Replacer
+
+By default, Cachios uses an internal `defaultReplacer` function to add FormData support to [object-hash](https://github.com/puleos/object-hash).
+
+To override this, set the `getReplaced` property of your Cachios instance:
+
+```js
+const cachios = require('cachios');
+
+cachios.getReplaced = function (thing) {
+  if (thing === 'foo') {
+    return 'bar';
+  }
+
+  return thing;
+};
+```
+
 ## License
 
 [MIT](LICENSE.md)
diff --git a/src/cachios.js b/src/cachios.js
index 773d3d1..5343e16 100644
--- a/src/cachios.js
+++ b/src/cachios.js
@@ -18,6 +18,23 @@ function defaultResponseCopier(response) {
   };
 }
 
+function defaultReplacer(thing) {
+  // object-hash doesn't handle FormData values, do it ourselves
+  // https://github.com/AlbinoDrought/cachios/issues/7
+  if (typeof FormData !== 'undefined' && thing instanceof FormData) {
+    var formDataValues = {};
+    var entriesIterator = thing.entries();
+    for (var entry = entriesIterator.next(); !entry.done || typeof entry.value !== 'undefined'; entry = entriesIterator.next()) {
+      formDataValues[entry.value[0]] = defaultReplacer(entry.value[1]);
+    }
+    return formDataValues;
+  }
+
+  // object-hash also doesn't support blobs, but I don't think we can read those synchronously
+
+  return thing;
+}
+
 function Cachios(axiosInstance, nodeCacheConf) {
   this.axiosInstance = axiosInstance;
   this.cache = new NodeCache(nodeCacheConf || {
@@ -29,10 +46,13 @@ function Cachios(axiosInstance, nodeCacheConf) {
 
   this.getCacheIdentifier = defaultCacheIdentifer;
   this.getResponseCopy = defaultResponseCopier;
+  this.getReplaced = defaultReplacer;
 }
 
 Cachios.prototype.getCacheKey = function (config) {
-  return hash(this.getCacheIdentifier(config));
+  return hash(this.getCacheIdentifier(config), {
+    replacer: this.getReplaced,
+  });
 };
 
 Cachios.prototype.getCachedValue = function (cacheKey) {
diff --git a/tests/getReplaced.spec.js b/tests/getReplaced.spec.js
new file mode 100644
index 0000000..f8fa1e9
--- /dev/null
+++ b/tests/getReplaced.spec.js
@@ -0,0 +1,79 @@
+/**
+ * @jest-environment jsdom
+ */const cachios = require('./../src');
+
+const axios = require('axios');
+const hash = require('object-hash');
+
+describe('cachios.getReplaced', () => {
+  test('should be set by default', () => {
+    expect(cachios.getReplaced).toBeDefined();
+  });
+
+  test('should not modify common values', () => {
+    [
+      { foo: 'bar' },
+      1234,
+      'Melon',
+      1.234,
+      null,
+      undefined,
+    ].forEach((thing) => {
+      expect(cachios.getReplaced(thing)).toEqual(thing);
+    });
+  });
+
+  test('should be used when creating cache keys', () => {
+    const instance = cachios.create(axios);
+
+    instance.getReplaced = (thing) => {
+      console.log(thing);
+      if (thing === 'bar') {
+        return 'baz';
+      }
+      return thing;
+    };
+
+    const expected = hash({
+      method: 'GET',
+      url: '/something',
+      params: {
+        foo: 'baz',
+      },
+      data: {
+        stuff: [
+          { foo: 'baz' },
+        ],
+      },
+    });
+
+    const actual = instance.getCacheKey({
+      method: 'GET',
+      url: '/something',
+      params: {
+        foo: 'bar',
+      },
+      data: {
+        stuff: [
+          { foo: 'bar' },
+        ],
+      },
+    });
+
+    expect(actual).toBe(expected);
+  });
+
+  test('should transform FormData to an object', () => {
+    const instance = cachios.create(axios);
+
+    const fd = new FormData();
+    fd.append('foo', 'bar');
+    fd.append('transform', 'hello');
+
+    expect(instance.getReplaced(fd)).toEqual({
+      foo: 'bar',
+      transform: 'hello',
+    });
+    console.log(typeof cachios);
+  });
+});