[Student][MBL-12337] Fix patch for PSPDFKit crash, add assertion (#49) (

#51)

buildSrc/src/main/java/com/instructure/android/buildtools/transform/ClassTransformer.kt

@@ -25,6 +25,12 @@ abstract class ClassTransformer {
     /** The name of this transformer */
     abstract val transformName: String
 
+    /**
+     *  Counts the number successful transforms performed by this Transformer and provides an assertion
+     *  that this count matches a given condition.
+     */
+    open val counter: TransformCounter = TransformCounter.Any
+
     /**
      * Called once the [ClassPool] has been populated. At this point all source files have been scanned and it should be
      * safe to obtain [CtClass]es, add package imports, append the classpath, or otherwise interact with the [ClassPool].
@@ -47,6 +53,13 @@ abstract class ClassTransformer {
      */
     abstract fun transform(cc: CtClass, classPool: ClassPool): Boolean
 
+    /** Invokes [transform] and updates the [counter] if the transform was successful */
+    fun performTransform(cc: CtClass, classPool: ClassPool): Boolean {
+        val transformed = transform(cc, classPool)
+        if (transformed) counter.increment()
+        return transformed
+    }
+
     val filter by lazy { createFilter() }
 
     open val includeExternalLibs: List<String> = emptyList()
@@ -75,3 +88,41 @@ abstract class ClassTransformer {
 
 }
 
+sealed class TransformCounter {
+    internal var transformCount: Int = 0
+
+    abstract fun assertCount()
+
+    fun increment() {
+        transformCount++
+    }
+
+    object Any : TransformCounter() {
+        override fun assertCount() = Unit
+    }
+
+    class AtLest(private val atLeast: Int) : TransformCounter() {
+        override fun assertCount() {
+            if (transformCount < atLeast) {
+                throw IllegalStateException("Transformer ran $transformCount time(s) but was required to run at least $atLeast time(s)")
+            }
+        }
+    }
+
+    class AtMost(private val atMost: Int) : TransformCounter() {
+        override fun assertCount() {
+            if (transformCount > atMost) {
+                throw IllegalStateException("Transformer ran $transformCount time(s) but was required to run at most $atMost time(s)")
+            }
+        }
+    }
+
+    class Exactly(private val exactly: Int) : TransformCounter() {
+        override fun assertCount() {
+            if (transformCount != exactly) {
+                throw IllegalStateException("Transformer ran $transformCount time(s) but was required to run exactly $exactly time(s)")
+            }
+        }
+    }
+}
+

buildSrc/src/main/java/com/instructure/android/buildtools/transform/PDFKitCrashFixTransformer.kt

@@ -25,7 +25,9 @@ class PDFKitCrashFixTransformer : ClassTransformer() {
 
     override val transformName = "PSPDFKitYUDoDis"
 
-    override val includeExternalLibs = listOf("pspdfkit-4.8.1.aar")
+    override val counter = TransformCounter.Exactly(1)
+
+    override val includeExternalLibs = listOf("pspdfkit:4.8.1")
 
     private val problemClassName = "com.pspdfkit.ui.PdfThumbnailGrid"
 

buildSrc/src/main/java/com/instructure/android/buildtools/transform/ProjectTransformer.kt

@@ -44,18 +44,19 @@ class ProjectTransformer(
     )
 
     override fun transform(transformInvocation: TransformInvocation) = with(transformInvocation) {
+        val start = System.currentTimeMillis()
 
         // Don't transform anything if this is a test APK; just copy inputs and return
         if (context.variantName.endsWith("AndroidTest")) {
-            inputs.forEach {
-                it.jarInputs.forEach {
+            inputs.forEach { input ->
+                input.jarInputs.forEach {
                     val dest = outputProvider.getContentLocation(it.name, it.contentTypes, it.scopes, Format.JAR)
                     when (it.status) {
                         Status.REMOVED -> dest.delete()
                         else -> it.file.copyTo(dest, true)
                     }
                 }
-                it.directoryInputs.forEach {
+                input.directoryInputs.forEach {
                     val dest = outputProvider.getContentLocation(it.name, it.contentTypes, it.scopes, Format.DIRECTORY)
                     it.file.copyRecursively(dest, overwrite = true)
                 }
@@ -88,7 +89,7 @@ class ProjectTransformer(
                         jarInput.file.copyTo(dest, true)
                         classPool.insertClassPath(jarInput.file.absolutePath)
                         if (jarInput.scopes.contains(QualifiedContent.Scope.SUB_PROJECTS)
-                            || includedExternalLibs.any { it in jarInput.file.absolutePath }) {
+                            || includedExternalLibs.any { it in jarInput.name }) {
                             candidateJars += jarInput.file to dest
                         }
                     }
@@ -112,7 +113,7 @@ class ProjectTransformer(
         // Transform files
         candidateFiles.forEach { (cc, src) ->
             try {
-                val modCount = transformers.count { it.filter.matches(cc) && it.transform(cc, classPool) }
+                val modCount = transformers.count { it.filter.matches(cc) && it.performTransform(cc, classPool) }
                 if (modCount > 0) src.writeBytes(cc.toBytecode())
             } catch (e: Throwable) {
                 println("Error transforming file ${src.nameWithoutExtension}")
@@ -130,7 +131,7 @@ class ProjectTransformer(
                     if (entry.name.endsWith(".class")) {
                         val cc = classPool[entry.name.substringBeforeLast(".class").replace("/", ".")]
                         if (cc.isFrozen) cc.defrost()
-                        if (transformers.count { it.filter.matches(cc) && it.transform(cc, classPool) } > 0) {
+                        if (transformers.count { it.filter.matches(cc) && it.performTransform(cc, classPool) } > 0) {
                             output.putNextEntry(JarEntry(entry.name))
                             output.write(cc.toBytecode())
                         } else {
@@ -148,6 +149,12 @@ class ProjectTransformer(
             output.close()
             input.close()
         }
+
+        // Assert the transform counts match their expected conditions
+        transformers.forEach { it.counter.assertCount() }
+
+        val end = System.currentTimeMillis()
+        println("    :Transform took ${(end - start) / 1000.0} seconds")
     }
 
     /** Copies [entry] from the [input] jar to the [output] jar without modification */