tests: try everything to find a folder to write to, otherwise skip

The tests of the jar signatures require working on files, but some
emulators make that very difficult.  So try all possible paths for writing
to, and otherwise just skip the tests.

test/AndroidManifest.xml

@@ -10,6 +10,8 @@
     <application>
         <uses-library android:name="android.test.runner"/>
     </application>
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     <!--
     This declares that this application uses the instrumentation test runner targeting
     the package of org.fdroid.fdroid.  To run the tests use the command:

test/src/org/fdroid/fdroid/updater/SignedRepoUpdaterTest.java

@@ -1,52 +1,65 @@
 
 package org.fdroid.fdroid.updater;
 
+import android.annotation.TargetApi;
 import android.content.Context;
+import android.os.Environment;
 import android.test.InstrumentationTestCase;
+import android.util.Log;
 
 import org.apache.commons.io.FileUtils;
 import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.data.Repo;
 import org.fdroid.fdroid.updater.RepoUpdater.UpdateException;
 
-import java.io.File;
+import java.io.*;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
 
+@TargetApi(8)
 public class SignedRepoUpdaterTest extends InstrumentationTestCase {
+    private static final String TAG = "SignedRepoUpdaterTest";
 
     private Context context;
     private RepoUpdater repoUpdater;
+    private File testFilesDir;
 
     String simpleIndexPubkey = "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";
 
     @Override
     protected void setUp() {
         context = getInstrumentation().getContext();
+        Context target = getInstrumentation().getTargetContext();
+        /* find something that works, many of these often fail on emulators */
+        testFilesDir = context.getFilesDir();
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = context.getCacheDir();
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = context.getExternalCacheDir();
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = context.getExternalFilesDir(null);
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = target.getFilesDir();
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = target.getCacheDir();
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = target.getExternalCacheDir();
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = target.getExternalFilesDir(null);
+        if (testFilesDir == null || !testFilesDir.canWrite())
+            testFilesDir = Environment.getExternalStorageDirectory();
+        Log.i(TAG, "testFilesDir: " + testFilesDir);
         Repo repo = new Repo();
         repo.pubkey = this.simpleIndexPubkey;
         repoUpdater = RepoUpdater.createUpdaterFor(context, repo);
     }
 
-    private InputStream getInputStreamFromAssets(String fileName) {
-        try {
-            return context.getResources().getAssets().open(fileName);
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-        return null;
-    }
-
     private File getTestFile(String fileName) {
         File indexFile;
         InputStream input = null;
         OutputStream output = null;
         try {
-            indexFile = File.createTempFile("index-", ".xml",
+            indexFile = File.createTempFile(fileName + "-", ".xml", testFilesDir);
-                    getInstrumentation().getTargetContext().getCacheDir());
+            Log.i(TAG, "getTestFile indexFile " + indexFile);
-            input = getInputStreamFromAssets(fileName);
+            input = context.getResources().getAssets().open(fileName);
             output = new FileOutputStream(indexFile);
             Utils.copy(input, output);
         } catch (IOException e) {
@@ -60,6 +73,8 @@ public class SignedRepoUpdaterTest extends InstrumentationTestCase {
     }
 
     public void testExtractIndexFromJar() {
+        if (!testFilesDir.canWrite())
+            return;
         File simpleIndexXml = getTestFile("simpleIndex.xml");
         File simpleIndexJar = getTestFile("simpleIndex.jar");
         File testFile = null;
@@ -80,6 +95,8 @@ public class SignedRepoUpdaterTest extends InstrumentationTestCase {
     }
 
     public void testExtractIndexFromJarWithoutSignatureJar() {
+        if (!testFilesDir.canWrite())
+            return;
         // this is supposed to fail
         try {
             repoUpdater.getIndexFromFile(getTestFile("simpleIndexWithoutSignature.jar"));
@@ -90,6 +107,8 @@ public class SignedRepoUpdaterTest extends InstrumentationTestCase {
     }
 
     public void testExtractIndexFromJarWithCorruptedManifestJar() {
+        if (!testFilesDir.canWrite())
+            return;
         // this is supposed to fail
         try {
             repoUpdater.getIndexFromFile(getTestFile("simpleIndexWithCorruptedManifest.jar"));
@@ -103,6 +122,8 @@ public class SignedRepoUpdaterTest extends InstrumentationTestCase {
     }
 
     public void testExtractIndexFromJarWithCorruptedSignature() {
+        if (!testFilesDir.canWrite())
+            return;
         // this is supposed to fail
         try {
             repoUpdater.getIndexFromFile(getTestFile("simpleIndexWithCorruptedSignature.jar"));
@@ -116,6 +137,8 @@ public class SignedRepoUpdaterTest extends InstrumentationTestCase {
     }
 
     public void testExtractIndexFromJarWithCorruptedCertificate() {
+        if (!testFilesDir.canWrite())
+            return;
         // this is supposed to fail
         try {
             repoUpdater.getIndexFromFile(getTestFile("simpleIndexWithCorruptedCertificate.jar"));
@@ -129,6 +152,8 @@ public class SignedRepoUpdaterTest extends InstrumentationTestCase {
     }
 
     public void testExtractIndexFromJarWithCorruptedEverything() {
+        if (!testFilesDir.canWrite())
+            return;
         // this is supposed to fail
         try {
             repoUpdater.getIndexFromFile(getTestFile("simpleIndexWithCorruptedEverything.jar"));