🐛 avoid NPE for empty source strings

Author: ebullient

src/main/java/dev/ebullient/convert/config/CompendiumConfig.java

@@ -1,5 +1,7 @@
 package dev.ebullient.convert.config;
 
+import static dev.ebullient.convert.StringUtil.isPresent;
+
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Arrays;
@@ -210,6 +212,7 @@ public String tagOfRaw(String tag) {
     public List<String> resolveBooks() {
         // works for 5eTools and pf2eTools
         return books.stream()
+                .filter(x -> isPresent(x))
                 .map(b -> {
                     if (b.endsWith(".json")) {
                         return b;
@@ -226,6 +229,7 @@ public List<String> resolveBooks() {
     public List<String> resolveAdventures() {
         // works for 5eTools and pf2eTools
         return adventures.stream()
+                .filter(x -> isPresent(x))
                 .map(a -> {
                     if (a.endsWith(".json")) {
                         return a;
@@ -240,6 +244,7 @@ public List<String> resolveAdventures() {
     }
 
     public Collection<String> resolveHomebrew() {
+        homebrew.removeIf(x -> isPresent(x));
         return Collections.unmodifiableCollection(homebrew);
     }
 

src/test/java/dev/ebullient/convert/tools/dnd5e/FilterAllTest.java

@@ -35,11 +35,16 @@ public static void setupDir() throws Exception {
                         "book": [
                             "XGE",
                             "XMM",
-                            "FRAiF"
+                            "FRAiF",
+                            ""
                         ],
                         "adventure": [
                             "OotA",
-                            "DIP"
+                            "DIP",
+                            ""
+                        ],
+                        "homebrew": [
+                            ""
                         ],
                         "reference": [
                             "*"