🐛 Fixed bug in ReplacingInputStream when used with ByteArrayInputStream

The code that was reading didn't handle reads with offsets properly.

Author: rmcdouga

rest-services/client/src/main/java/com/_4point/aem/docservices/rest_services/client/helpers/ReplacingInputStream.java

@@ -110,7 +110,7 @@ public int read(byte[] ba) throws IOException {
 	public int read(byte[] ba, int off, int len) throws IOException {
 		for (int i = off; i < len; i++) {
 			int b = read();
-			if (b == -1) return i == 0 ? -1 : i;	// If we haven't read anything, return -1 otherwise, return the number of bytes we have read.
+			if (b == -1) return (i - off) == 0 ? -1 : i - off;	// If we haven't read anything, return -1 otherwise, return the number of bytes we have read.
 			ba[i] = (byte)b;
 		}
 		return len;

rest-services/client/src/test/java/com/_4point/aem/docservices/rest_services/client/helpers/ReplacingInputStreamTest.java

@@ -10,6 +10,7 @@
 import java.util.stream.Stream;
 
 import org.apache.commons.io.IOUtils;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
@@ -74,4 +75,28 @@ void shouldReplaceUsingStringConstructor(String input, String pattern, String re
 	        }
 		}
 	}
+	
+	private static final String MODIFICATION_TARGETS_FORMAT_STR = """
+			'contextPath = %sresult[1];'
+			'"%s/etc.clientlibs/toggles.json"'
+			""";
+
+	@Test
+	void shouldWorkWithByteArrayInputStream() throws IOException {
+		String aemResponseText = "Value should be modified. " + MODIFICATION_TARGETS_FORMAT_STR.formatted("", "");
+		String expectedResult = "Value should be modified. " + MODIFICATION_TARGETS_FORMAT_STR.formatted("\" + /aem\" + ", "");
+		
+		byte[] aemResponseBytes = aemResponseText.getBytes();
+		byte[] expectedResultBytes = expectedResult.getBytes();
+   		String target = "contextPath = result[1];";
+
+   		String replacement = "contextPath = \" + /aem\" + result[1];";
+   		try (ReplacingInputStream replacingInputStream = new ReplacingInputStream(new ByteArrayInputStream(aemResponseBytes), target, replacement)) {
+   			byte[] result = replacingInputStream.readAllBytes();
+   			
+   			assertArrayEquals(aemResponseBytes, new ByteArrayInputStream(aemResponseBytes).readAllBytes());
+   			assertArrayEquals(expectedResultBytes, result);
+   		}
+	}
+
 }

rest-services/client/src/test/java/com/_4point/aem/docservices/rest_services/client/helpers/ReplacingOutputStreamTest.java

@@ -10,6 +10,7 @@
 import java.util.stream.Stream;
 
 import org.apache.commons.io.IOUtils;
+import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
@@ -73,4 +74,29 @@ void shouldReplaceUsingStringConstructor(String input, String pattern, String re
 			assertEquals(expected, bos.toString());
 		}
 	}
+	
+	
+	private static final String MODIFICATION_TARGETS_FORMAT_STR = """
+			'contextPath = %sresult[1];'
+			'"%s/etc.clientlibs/toggles.json"'
+			""";
+
+	@Test
+	void shouldWorkWithByteArrayOutputStream() throws IOException {
+		String aemResponseText = "Value should be modified. " + MODIFICATION_TARGETS_FORMAT_STR.formatted("", "");
+		String expectedResult = "Value should be modified. " + MODIFICATION_TARGETS_FORMAT_STR.formatted("\" + /aem\" + ", "");
+		
+		byte[] aemResponseBytes = aemResponseText.getBytes();
+		byte[] expectedResultBytes = expectedResult.getBytes();
+   		String target = "contextPath = result[1];";
+
+   		String replacement = "contextPath = \" + /aem\" + result[1];";
+   		var os = new ByteArrayOutputStream();
+   		try (os; ReplacingOutputStream replacingOutputStream = new ReplacingOutputStream(os , target, replacement)) {
+   			replacingOutputStream.write(aemResponseBytes);
+   			
+   		}
+   		assertArrayEquals(expectedResultBytes, os.toByteArray());
+	}
+
 }