From 8bdf8db5ecf1a444b45a7f02cbd63b8cfbff2631 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <valkar207@gmail.com>
Date: Tue, 12 Sep 2017 22:53:42 -0700
Subject: [PATCH] feat(unmarshal): add rudimentary support for $transform

---
 src/unmarshal/index.js | 13 +++++++++----
 src/unmarshal/util.js  |  8 ++++++--
 test/unit.test.js      | 16 ++++++++++++++--
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/src/unmarshal/index.js b/src/unmarshal/index.js
index ddbb32f..f4e0c9b 100644
--- a/src/unmarshal/index.js
+++ b/src/unmarshal/index.js
@@ -120,7 +120,8 @@ function visitArray(arr, schema, projection, path) {
     }
 
     try {
-      handleCast(arr, index, schema._paths[newPath].$type);
+      const pathOptions = schema._paths[newPath];
+      handleCast(arr, index, pathOptions.$type, pathOptions.$transform);
     } catch(err) {
       error.markError(join(path, index, true), err);
     }
@@ -168,8 +169,9 @@ function visitObject(obj, schema, projection, path) {
       // If type not specified, no type casting
       return;
     }
+    const pathOptions = schema._paths[newPath];
 
-    if (schema._paths[newPath].$type === Array ||
+    if (pathOptions.$type === Array ||
         Array.isArray(schema._paths[newPath].$type)) {
       let res = visitArray(value, schema, projection, newPath);
       if (res.error) {
@@ -178,11 +180,14 @@ function visitObject(obj, schema, projection, path) {
       }
       obj[key] = res.value;
       return;
-    } else if (schema._paths[newPath].$type === Object) {
+    } else if (pathOptions.$type === Object) {
       if (value == null) {
         delete obj[key];
         return;
       }
+      if (pathOptions.$transform != null) {
+        value = pathOptions.$transform(obj[key]);
+      }
       let res = visitObject(value, schema, projection, newPath);
       if (res.error) {
         debug('merge', res.error.errors);
@@ -193,7 +198,7 @@ function visitObject(obj, schema, projection, path) {
     }
 
     try {
-      handleCast(obj, key, schema._paths[newPath].$type);
+      handleCast(obj, key, pathOptions.$type, pathOptions.$transform);
     } catch(err) {
       error.markError(join(path, key, true), err);
     }
diff --git a/src/unmarshal/util.js b/src/unmarshal/util.js
index 6381c5f..5eff69e 100644
--- a/src/unmarshal/util.js
+++ b/src/unmarshal/util.js
@@ -2,8 +2,12 @@
 
 const to = require('../to');
 
-exports.handleCast = function(obj, key, type) {
-  obj[key] = to(obj[key], type);
+const noop = x => x;
+
+exports.handleCast = function(obj, key, type, transform) {
+  transform = transform == null ? noop : transform;
+  console.log('F', transform)
+  obj[key] = to(transform(obj[key]), type);
 };
 
 exports.realPathToSchemaPath = function(path) {
diff --git a/test/unit.test.js b/test/unit.test.js
index 881b4f1..816a5c0 100644
--- a/test/unit.test.js
+++ b/test/unit.test.js
@@ -600,14 +600,26 @@ describe('unmarshal()', function() {
 
     assert.deepEqual(Test.paths().filter(v => !v.$description), [
       { path: 'str', $type: 'string' }
-    ])
+    ]);
     assert.deepEqual(Test.paths().filter(v => !!v.$description), [
       {
         path: 'num',
         $type: 'number',
         $description: 'this is a number'
       }
-    ])
+    ]);
+  });
+
+  it('$transform', function() {
+    const Test = new Archetype({
+      str: {
+        $type: Object,
+        $transform: JSON.parse
+      }
+    }).compile();
+
+    const doc = new Test({ str: JSON.stringify({ hello: 'world' }) });
+    assert.deepEqual(doc.str, { hello: 'world' });
   });
 
   it('to()', function() {