Support diffing format versions for DEX files

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Add `--summary-only` flag.
 - Support diffing bytecode versions for classes.
 - Support diffing Kotlin metadata versions for classes.
+- Support diffing format versions for DEX files.
 
 **Changed**
 - Replace `com.jakewharton.diffuse.io.Size` with `me.saket.bytesize.ByteSize` in the APIs.

formats/api/formats.api

@@ -243,6 +243,7 @@ public final class com/jakewharton/diffuse/format/Dex : com/jakewharton/diffuse/
 	public final fun getClasses ()Ljava/util/List;
 	public fun getDeclaredMembers ()Ljava/util/List;
 	public fun getFilename ()Ljava/lang/String;
+	public final fun getFormatVersion ()I
 	public fun getMembers ()Ljava/util/List;
 	public fun getReferencedMembers ()Ljava/util/List;
 	public final fun getStrings ()Ljava/util/List;

formats/src/main/kotlin/com/jakewharton/diffuse/format/Dex.kt

@@ -2,13 +2,15 @@ package com.jakewharton.diffuse.format
 
 import com.android.dex.ClassDef
 import com.android.dex.Dex as AndroidDex
+import com.android.dex.DexFormat as AndroidDexFormat
 import com.android.dex.FieldId
 import com.android.dex.MethodId
 import com.jakewharton.diffuse.io.Input
 
 class Dex
 private constructor(
   override val filename: String,
+  val formatVersion: Int,
   val strings: List<String>,
   val types: List<String>,
   val classes: List<TypeDescriptor>,
@@ -26,6 +28,7 @@ private constructor(
     val mappedReferencedMembers = referencedMembers.map(mapping::get)
     return Dex(
       filename,
+      formatVersion,
       strings,
       types,
       mappedClasses,
@@ -38,7 +41,15 @@ private constructor(
     @JvmStatic
     @JvmName("parse")
     fun Input.toDex(): Dex {
-      val dex = AndroidDex(toByteArray())
+      val bytes = toByteArray()
+      val dex = AndroidDex(bytes)
+      val formatVersion =
+        String(
+            bytes,
+            offset = AndroidDexFormat.MAGIC_PREFIX.length,
+            length = AndroidDexFormat.VERSION_CURRENT.length,
+          )
+          .toInt()
       val classes = dex.classDefs().map { TypeDescriptor(dex.typeNames()[it.typeIndex]) }
       val declaredTypeIndices = dex.classDefs().map(ClassDef::getTypeIndex).toSet()
       val (declaredMethods, referencedMethods) =
@@ -53,7 +64,15 @@ private constructor(
           .mapEach { it.map(dex::getField) }
       val declaredMembers = declaredMethods + declaredFields
       val referencedMembers = referencedMethods + referencedFields
-      return Dex(name, dex.strings(), dex.typeNames(), classes, declaredMembers, referencedMembers)
+      return Dex(
+        name,
+        formatVersion,
+        dex.strings(),
+        dex.typeNames(),
+        classes,
+        declaredMembers,
+        referencedMembers,
+      )
     }
 
     private fun <T, R> Pair<T, T>.mapEach(body: (T) -> R): Pair<R, R> = body(first) to body(second)

formats/src/test/kotlin/com/jakewharton/diffuse/format/ClassTest.kt

@@ -7,6 +7,7 @@ import assertk.assertions.hasSize
 import assertk.assertions.index
 import assertk.assertions.isEqualTo
 import com.jakewharton.diffuse.format.Class.Companion.toClass
+import com.jakewharton.diffuse.testing.requireResource
 import java.util.function.Function
 import org.junit.Test
 

formats/src/test/kotlin/com/jakewharton/diffuse/format/DexTest.kt

@@ -2,14 +2,38 @@ package com.jakewharton.diffuse.format
 
 import assertk.assertThat
 import assertk.assertions.hasSize
+import assertk.assertions.isEqualTo
 import assertk.assertions.prop
 import com.jakewharton.diffuse.format.Dex.Companion.toDex
+import com.jakewharton.diffuse.io.Input.Companion.asInput
+import com.jakewharton.diffuse.testing.requireResource
+import okio.ByteString.Companion.toByteString
 import org.junit.Test
 
 class DexTest {
   @Test
   fun parameterTypeIsUnsigned() {
-    val dex = DexTest::class.java.getResource("/params32769.dex").asInput().toDex()
+    val dex = DexTest::class.java.requireResource("/params32769.dex").asInput().toDex()
     assertThat(dex).prop(Dex::declaredMembers).hasSize(32769)
   }
+
+  @Test
+  fun formatVersion() {
+    val bytes = DexTest::class.java.requireResource("/params32769.dex").asInput().toByteArray()
+    val dex35 = bytes.toByteString().asInput("dex35.dex").toDex()
+    assertThat(dex35.formatVersion).isEqualTo(35)
+
+    val dex38 =
+      bytes
+        .clone()
+        .apply {
+          set(4, '0'.code.toByte())
+          set(5, '3'.code.toByte())
+          set(6, '8'.code.toByte())
+        }
+        .toByteString()
+        .asInput("dex38.dex")
+        .toDex()
+    assertThat(dex38.formatVersion).isEqualTo(38)
+  }
 }

formats/src/test/kotlin/com/jakewharton/diffuse/format/ResourceInput.kt

@@ -1,17 +1,12 @@
 package com.jakewharton.diffuse.format
 
 import com.jakewharton.diffuse.io.Input
-import java.lang.Class
 import java.net.URL
 import okio.buffer
 import okio.source
 
 fun URL.asInput(): Input = ResourceInput(this)
 
-fun Class<*>.requireResource(name: String): URL {
-  return checkNotNull(getResource(name)) { "Resource $name not found." }
-}
-
 private class ResourceInput(private val url: URL) : Input {
   override val name
     get() = url.path.substringAfterLast('/')

reports/build.gradle

@@ -9,4 +9,5 @@ dependencies {
 
   testImplementation libs.junit
   testImplementation libs.assertk
+  testImplementation projects.testHelpers
 }

reports/src/main/kotlin/com/jakewharton/diffuse/diff/DexDiff.kt

@@ -16,6 +16,10 @@ import com.jakewharton.picnic.renderText
 internal class DexDiff(val oldDexes: List<Dex>, val newDexes: List<Dex>) : BinaryDiff {
   val isMultidex = oldDexes.size > 1 || newDexes.size > 1
 
+  val formatVersions =
+    componentDiff(oldDexes, newDexes) { dex ->
+      listOf("${dex.filename}: ${dex.formatVersion}")
+    }
   val strings = componentDiff(oldDexes, newDexes) { it.strings }
   val types = componentDiff(oldDexes, newDexes) { it.types }
   val classes = componentDiff(oldDexes, newDexes) { it.classes }
@@ -30,7 +34,8 @@ internal class DexDiff(val oldDexes: List<Dex>, val newDexes: List<Dex>) : Binar
   val referencedFields =
     componentDiff(oldDexes, newDexes) { it.referencedMembers.filterIsInstance<Field>() }
 
-  val changed = strings.changed || types.changed || methods.changed || fields.changed
+  val changed =
+    formatVersions.changed || strings.changed || types.changed || methods.changed || fields.changed
 
   override fun toTextReport(summaryOnly: Boolean): Report = DexDiffTextReport(this, summaryOnly)
 }
@@ -117,6 +122,7 @@ internal fun DexDiff.toSummaryTable() = diffuseTable {
   .renderText()
 
 internal fun DexDiff.toDetailReport() = buildString {
+  appendComponentDiff("FORMAT VERSIONS", formatVersions)
   appendComponentDiff("STRINGS", strings)
   appendComponentDiff("TYPES", types)
   appendComponentDiff("METHODS", methods)

reports/src/test/kotlin/com/jakewharton/diffuse/DexDiffTest.kt

@@ -0,0 +1,98 @@
+package com.jakewharton.diffuse
+
+import assertk.assertThat
+import assertk.assertions.isEqualTo
+import com.jakewharton.diffuse.diff.DexDiff
+import com.jakewharton.diffuse.diff.toDetailReport
+import com.jakewharton.diffuse.format.Dex
+import com.jakewharton.diffuse.format.Dex.Companion.toDex
+import com.jakewharton.diffuse.io.Input.Companion.asInput
+import com.jakewharton.diffuse.testing.requireResource
+import okio.ByteString.Companion.toByteString
+import org.junit.Test
+
+class DexDiffTest {
+  @Test
+  fun formatVersionsSingleDexSame() {
+    val diff =
+      DexDiff(
+        oldDexes = listOf(Dex("classes.dex", 35)),
+        newDexes = listOf(Dex("classes.dex", 35)),
+      )
+
+    assertThat(diff.changed).isEqualTo(false)
+    assertThat(diff.toDetailReport()).isEqualTo("")
+  }
+
+  @Test
+  fun formatVersionsSingleDexChanged() {
+    val diff =
+      DexDiff(
+        oldDexes = listOf(Dex("classes.dex", 35)),
+        newDexes = listOf(Dex("classes.dex", 38)),
+      )
+
+    assertThat(diff.changed).isEqualTo(true)
+    assertThat(diff.toDetailReport())
+      .isEqualTo(
+        """
+        |
+        |FORMAT VERSIONS:
+        |
+        |   old │ new │ diff      
+        |  ─────┼─────┼───────────
+        |   1   │ 1   │ 0 (+1 -1) 
+        |  
+        |  + classes.dex: 38
+        |  
+        |  - classes.dex: 35
+        |  
+        |"""
+          .trimMargin()
+      )
+  }
+
+  @Test
+  fun formatVersionsMultidexChanged() {
+    val diff =
+      DexDiff(
+        oldDexes = listOf(Dex("classes.dex", 35), Dex("classes2.dex", 35)),
+        newDexes = listOf(Dex("classes.dex", 35), Dex("classes2.dex", 38)),
+      )
+
+    assertThat(diff.changed).isEqualTo(true)
+    assertThat(diff.toDetailReport())
+      .isEqualTo(
+        """
+        |
+        |FORMAT VERSIONS:
+        |
+        |   old │ new │ diff      
+        |  ─────┼─────┼───────────
+        |   2   │ 2   │ 0 (+1 -1) 
+        |  
+        |  + classes2.dex: 38
+        |  
+        |  - classes2.dex: 35
+        |  
+        |"""
+          .trimMargin()
+      )
+  }
+}
+
+private fun Dex(name: String, version: Int): Dex {
+  val (tens, ones) = version.toString().toCharArray()
+  return DexDiffTest::class
+    .java
+    .requireResource("/params32769.dex")
+    .readBytes()
+    .apply {
+      set(4, '0'.code.toByte())
+      set(5, tens.code.toByte())
+      set(6, ones.code.toByte())
+    }
+    .toByteString()
+    .asInput(name)
+    .toDex()
+}

test-helpers/src/main/kotlin/com/jakewharton/diffuse/testing/requireResource.kt

@@ -0,0 +1,7 @@
+package com.jakewharton.diffuse.testing
+
+import java.net.URL
+
+fun Class<*>.requireResource(name: String): URL {
+  return checkNotNull(getResource(name)) { "Resource $name not found." }
+}