Relax setIn requirements (#38)

Previously superglue required that the page be shaped the exact same way
in order to use `setIn`. That proved a bit too strict and cumbersome in
situations where we want shape to be 1% different. For example, modals.

This removes that restriction

superglue/lib/utils/immutability.js

@@ -83,15 +83,6 @@ function atKey(node, key) {
     )
   }
 
-  if (
-    isObject(node) &&
-    !Object.prototype.hasOwnProperty.call(node, key)
-  ) {
-    throw new KeyPathError(
-      `Expected to find key: ${key} in object ${JSON.stringify(node)}`
-    )
-  }
-
   if (Array.isArray(node) && id) {
     let child
     for (let i = 0; i < node.length; i++) {

superglue/spec/lib/utils/immutability.spec.js

@@ -40,13 +40,6 @@ describe('setIn', () => {
     expect(page).toBe(clone)
   })
 
-  it('throws an error when parents dont exist', () => {
-    const page = { a: { b: 2 } }
-    expect(() => {
-      setIn(page, 'a.c', 'foo')
-    }).toThrow(new KeyPathError('Expected to find key: c in object {"b":2}'))
-  })
-
   it('throws an error when parents are untranversible', () => {
     const page = { a: { b: 2 } }
     expect(() => {
@@ -102,4 +95,20 @@ describe('setIn', () => {
       a: { b: [{ foo_id: 1 }, { foo_id: 2, foo: 'bar' }, { foo_id: 3 }] },
     })
   })
+
+  it('sets if the key on the object does not exist', () => {
+    const page = { a: { b: {hello: "world"} } }
+    const clone = setIn(page, 'a.c', 'foo')
+
+    expect(page.a.b).toBe(clone.a.b)
+    expect(clone).toEqual({ a: { b: {hello: "world"} , c: 'foo' }})
+  })
+
+  it('sets if the index on the array does not exist', () => {
+    const page = { a: [{c: 4}, {b: 5}] }
+    const clone = setIn(page, 'a.0', 'foo')
+
+    expect(page.a[1]).toBe(clone.a[1])
+    expect(clone).toEqual({ a: ['foo', {b: 5}]})
+  })
 })