From de537f0b1457192d07eec2348dbcc378d60b7758 Mon Sep 17 00:00:00 2001
From: Chris Beams <chris@beams.io>
Date: Mon, 24 Feb 2020 10:36:40 +0100
Subject: [PATCH] Throw UncheckedIOException on directory creation errors

Previously, Config#mkdir and #mkAppDir threw ConfigException if any
underlying IOException was thrown from Files#createDirectory or
Files#createDirectories respectively. This resulted in only a simple
error message being reported at the command line and the details of the
underlying exception's stack trace were lost. This change wraps and
rethrows the underlying IOException as an UncheckedIOException such that
it gets caught by the catch(Throwable) clause in BisqExecutable, which
does print a stacktrace to stderr. This is the way it always should have
worked; throwing ConfigException in these cases was an oversight in the
original implementation. This change also removes the ConfigException
constructor that allows for passing a nested exception to be wrapped as
there is actually no use case for this now that these two anomalies have
been corrected.

This change was made in the process of attempting to reproduce #3998.
---
 common/src/main/java/bisq/common/config/Config.java          | 4 ++--
 common/src/main/java/bisq/common/config/ConfigException.java | 4 ----
 common/src/test/java/bisq/common/config/ConfigTests.java     | 5 +++--
 3 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/common/src/main/java/bisq/common/config/Config.java b/common/src/main/java/bisq/common/config/Config.java
index a9fc517a215..dac6afe545c 100644
--- a/common/src/main/java/bisq/common/config/Config.java
+++ b/common/src/main/java/bisq/common/config/Config.java
@@ -802,7 +802,7 @@ private static File mkAppDataDir(File appDataDir) {
         try {
             Files.createDirectories(path);
         } catch (IOException ex) {
-            throw new ConfigException(ex, "Application data directory '%s' could not be created", path);
+            throw new UncheckedIOException(format("Application data directory '%s' could not be created", path), ex);
         }
         return appDataDir;
     }
@@ -819,7 +819,7 @@ private static File mkdir(File parent, String child) {
             try {
                 Files.createDirectory(path);
             } catch (IOException ex) {
-                throw new ConfigException(ex, "Directory '%s' could not be created", path);
+                throw new UncheckedIOException(format("Directory '%s' could not be created", path), ex);
             }
         }
         return dir;
diff --git a/common/src/main/java/bisq/common/config/ConfigException.java b/common/src/main/java/bisq/common/config/ConfigException.java
index 4a4e955456d..0d709dcf53e 100644
--- a/common/src/main/java/bisq/common/config/ConfigException.java
+++ b/common/src/main/java/bisq/common/config/ConfigException.java
@@ -7,8 +7,4 @@ public class ConfigException extends BisqException {
     public ConfigException(String format, Object... args) {
         super(format, args);
     }
-
-    public ConfigException(Throwable cause, String format, Object... args) {
-        super(cause, format, args);
-    }
 }
diff --git a/common/src/test/java/bisq/common/config/ConfigTests.java b/common/src/test/java/bisq/common/config/ConfigTests.java
index de9593917be..6109342b339 100644
--- a/common/src/test/java/bisq/common/config/ConfigTests.java
+++ b/common/src/test/java/bisq/common/config/ConfigTests.java
@@ -7,6 +7,7 @@
 import java.io.IOException;
 import java.io.PrintStream;
 import java.io.PrintWriter;
+import java.io.UncheckedIOException;
 
 import org.junit.Rule;
 import org.junit.Test;
@@ -228,10 +229,10 @@ public void whenConfigIsConstructed_thenAppDataDirAndSubdirsAreCreated() {
     }
 
     @Test
-    public void whenAppDataDirCannotBeCreated_thenConfigExceptionIsThrown() throws IOException {
+    public void whenAppDataDirCannotBeCreated_thenUncheckedIoExceptionIsThrown() throws IOException {
         // set a userDataDir that is actually a file so appDataDir cannot be created
         File aFile = Files.createTempFile("A", "File").toFile();
-        exceptionRule.expect(ConfigException.class);
+        exceptionRule.expect(UncheckedIOException.class);
         exceptionRule.expectMessage(containsString("Application data directory"));
         exceptionRule.expectMessage(containsString("could not be created"));
         configWithOpts(opt(USER_DATA_DIR, aFile));