Skip checking binary files for possible JUnit dependencies

changelog/@unreleased/pr-886.v2.yml

@@ -0,0 +1,11 @@
+type: fix
+fix:
+  description: |-
+    Treat MalformedInputException as binary files that are not necessary to
+    scan for old JUnit dependencies.
+
+    Rethrow any non-IOExeception (such as UncheckedIOException wrapping
+    MalformedInputException) with more useful error message indicating a
+    file could not be scanned (e.g. ).
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/886

gradle-baseline-java/src/main/groovy/com/palantir/baseline/tasks/CheckJUnitDependencies.java

@@ -17,10 +17,12 @@
 package com.palantir.baseline.tasks;
 
 import com.google.common.base.Preconditions;
+import com.google.common.base.Throwables;
 import com.palantir.baseline.plugins.BaselineTesting;
 import java.io.File;
-import java.io.IOException;
+import java.nio.charset.MalformedInputException;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.Optional;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
@@ -149,15 +151,24 @@ private boolean sourceSetMentionsJUnit5Api(SourceSet ss) {
     }
 
     private boolean fileContainsSubstring(File file, Predicate<String> substring) {
-        try (Stream<String> lines = Files.lines(file.toPath())) {
+        Path path = file.toPath();
+        try (Stream<String> lines = Files.lines(path)) {
             boolean hit = lines.anyMatch(substring::test);
             getProject().getLogger().debug("[{}] {}", hit ? "hit" : "miss", file);
             return hit;
-        } catch (IOException e) {
-            throw new RuntimeException("Unable to check file " + file, e);
+        } catch (Exception e) {
+            if (isCausedByBinaryFile(e)) {
+                getLogger().warn("Unable to check binary file {} due to {}", path, e.getMessage());
+                return false;
+            }
+            throw new RuntimeException("Unable to check file " + path, e);
         }
     }
 
+    private static boolean isCausedByBinaryFile(Exception exception) {
+        return Throwables.getCausalChain(exception).stream().anyMatch(MalformedInputException.class::isInstance);
+    }
+
     private static boolean isJunitJupiter(ModuleVersionIdentifier dep) {
         return "org.junit.jupiter".equals(dep.getGroup()) && "junit-jupiter".equals(dep.getName());
     }