1 /*
2  * Copyright (C) 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 @file:JvmName("ParcelUtils")
18 
19 package com.android.testutils
20 
21 import android.os.Parcel
22 import android.os.Parcelable
23 import kotlin.test.assertTrue
24 import kotlin.test.fail
25 
26 /**
27  * Return a new instance of `T` after being parceled then unparceled.
28  */
29 fun <T : Parcelable> parcelingRoundTrip(source: T): T {
30     val creator: Parcelable.Creator<T>
31     try {
32         creator = source.javaClass.getField("CREATOR").get(null) as Parcelable.Creator<T>
33     } catch (e: IllegalAccessException) {
34         fail("Missing CREATOR field: " + e.message)
35     } catch (e: NoSuchFieldException) {
36         fail("Missing CREATOR field: " + e.message)
37     }
38 
39     var p = Parcel.obtain()
40     source.writeToParcel(p, /* flags */ 0)
41     p.setDataPosition(0)
42     val marshalled = p.marshall()
43     p = Parcel.obtain()
44     p.unmarshall(marshalled, 0, marshalled.size)
45     p.setDataPosition(0)
46     return creator.createFromParcel(p)
47 }
48 
49 /**
50  * Assert that after being parceled then unparceled, `source` is equal to the original
51  * object. If a customized equals function is provided, uses the provided one.
52  */
53 @JvmOverloads
54 fun <T : Parcelable> assertParcelingIsLossless(
55     source: T,
56     equals: (T, T) -> Boolean = { a, b -> a == b }
57 ) {
58     val actual = parcelingRoundTrip(source)
59     assertTrue(equals(source, actual), "Expected $source, but was $actual")
60 }
61 
62 @JvmOverloads
63 fun <T : Parcelable> assertParcelSane(
64     obj: T,
65     fieldCount: Int,
66     equals: (T, T) -> Boolean = { a, b -> a == b }
67 ) {
68     assertFieldCountEquals(fieldCount, obj::class.java)
69     assertParcelingIsLossless(obj, equals)
70 }
71