From 25f829b7adc348dd49f0505bc8a5951bf13f6a52 Mon Sep 17 00:00:00 2001
From: Gleb Bahmutov <gleb.bahmutov@gmail.com>
Date: Thu, 20 Jul 2017 22:48:19 -0400
Subject: [PATCH] feat(compound): support two level transforms, close #8

---
 README.md                     | 10 +++++++---
 src/change-by-example-spec.js | 10 ++++++++++
 src/utils.js                  | 14 +++++++++++++-
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 1eb439c..a431851 100644
--- a/README.md
+++ b/README.md
@@ -71,11 +71,15 @@ console.log(f({
 * [x] property rename
 * [x] simple string transforms from [Ramda](http://ramdajs.com/docs/)
   and [Lodash](https://lodash.com/docs/)
-* [x] deep source paths [#3](https://github.com/bahmutov/change-by-example/issues/3)
-* [x] deep destination paths [#7](https://github.com/bahmutov/change-by-example/issues/7)
-* [ ] compound transforms like `trim + toLower`
+* [x] deep source paths [#3][3]
+* [x] deep destination paths [#7][7]
+* [x] compound transforms like `trim + toLower` [#8][8]
 * [ ] combining values like `.fullName = .first` + `.last`
 
+[3]: https://github.com/bahmutov/change-by-example/issues/3
+[7]: https://github.com/bahmutov/change-by-example/issues/7
+[8]: https://github.com/bahmutov/change-by-example/issues/8
+
 ## Debugging
 
 Run with environment variable `DEBUG=change-by-example ...`
diff --git a/src/change-by-example-spec.js b/src/change-by-example-spec.js
index 0da267f..4b471cf 100644
--- a/src/change-by-example-spec.js
+++ b/src/change-by-example-spec.js
@@ -59,6 +59,16 @@ describe('change-by-example', () => {
     finds(source, destination)
   })
 
+  it('finds 2 level transforms', () => {
+    const source = {
+      name: '   joe '
+    }
+    const destination = {
+      name: 'JOE'
+    }
+    finds(source, destination)
+  })
+
   it('works with nested objects', () => {
     const source = {
       age: 42,
diff --git a/src/utils.js b/src/utils.js
index 1a013c0..ee871c9 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -14,6 +14,18 @@ const otherTransforms = [
 
 const transforms = otherTransforms.concat(stringTransforms)
 
+// combinations of two transforms
+const combine = (t, s) => {
+  const combined = {
+    f: R.compose(t.f, s.f),
+    name: `${t.name} * ${s.name}`
+  }
+  return combined
+}
+const transforms2 = R.flatten(
+  transforms.map(t => transforms.map(s => combine(t, s)))
+)
+
 // returns transform function that is Transform(get view lens)
 const findTransform = source => value => {
   // given source object and desired value
@@ -27,7 +39,7 @@ const findTransform = source => value => {
 
   paths.some(path => {
     const sourceValue = R.view(R.lensPath(path), source)
-    const foundTransform = transforms.some(t => {
+    const foundTransform = transforms2.some(t => {
       try {
         const out = t.f(sourceValue)
         if (R.equals(value, out)) {