[8.19] (backport #18124) test: explicitly load ascii fixture as ascii, do line-oriented parsing (#18125)

* test: explicitly load ascii fixture as ascii, do line-oriented parsing (#18124)

(cherry picked from commit 6a51c82)

# Conflicts:
#	logstash-core/src/test/java/org/logstash/EventTest.java

* Update logstash-core/src/test/java/org/logstash/EventTest.java

---------

Co-authored-by: Rye Biesemeyer <[email protected]>

Author: mergify[bot]

logstash-core/src/test/java/org/logstash/EventTest.java

@@ -33,6 +33,7 @@
 import java.util.HexFormat;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 import org.jruby.RubyString;
 import org.jruby.RubySymbol;
 import org.jruby.RubyTime;
@@ -149,7 +150,7 @@ public void bigNumsBinaryRoundtrip() throws Exception {
 
     @Test
     public void deserializeStringrefExtensionEnabled() throws Exception {
-        byte[] stringrefCBOR = loadAnnotatedCBORFixture("stringref-enabled.annotated-cbor.txt");
+        byte[] stringrefCBOR = loadAnnotatedCBORFixture("stringref-enabled.annotated-cbor.asc");
         Event event = Event.deserialize(stringrefCBOR);
         event.getField("[event][original]");
         assertEquals("stringref", event.getField("test"));
@@ -158,7 +159,7 @@ public void deserializeStringrefExtensionEnabled() throws Exception {
 
     @Test
     public void deserializeStringrefExtensionDisabled() throws Exception {
-        byte[] stringrefCBOR = loadAnnotatedCBORFixture("stringref-disabled.annotated-cbor.txt");
+        byte[] stringrefCBOR = loadAnnotatedCBORFixture("stringref-disabled.annotated-cbor.asc");
         Event event = Event.deserialize(stringrefCBOR);
         event.getField("[event][original]");
         assertEquals("stringref", event.getField("test"));
@@ -627,9 +628,13 @@ static byte[] loadAnnotatedCBORFixture(String name) throws IOException {
         try (InputStream resourceAsStream = EventTest.class.getResourceAsStream(name)) {
             assertNotNull(resourceAsStream);
 
-            String annotated = new String(resourceAsStream.readAllBytes(), StandardCharsets.UTF_8);
-            // annotated CBOR: strip #-initiated line comments, then strip whitespace to get hex
-            String hexBytes = annotated.replaceAll("#.*(\\n|$)", "").replaceAll("\\s", "");
+            final String annotatedFixture = new String(resourceAsStream.readAllBytes(), StandardCharsets.US_ASCII);
+            final String hexBytes = annotatedFixture.lines()
+                    // strip #-prefixed annotations
+                    .map(line -> line.split("#", 2)[0])
+                    // strip all remaining whitespace
+                    .map(line -> line.replaceAll("\\s", ""))
+                    .collect(Collectors.joining());
 
             // result should be even number of hex digits
             assert hexBytes.matches("(?i:[0-9a-f]{2})*");