test(appsec): add integration tests for file content size and count limits

Author: jandro996

dd-java-agent/instrumentation-testing/src/main/groovy/datadog/trace/agent/test/base/HttpServerTest.groovy

@@ -1674,6 +1674,56 @@ abstract class HttpServerTest<SERVER> extends WithHttpServer<SERVER> {
     response.close()
   }
 
+  def 'test instrumentation gateway file upload content truncated at max size'() {
+    setup:
+    assumeTrue(testBodyFilesContent())
+    def maxContentBytes = 4096
+    def body = new MultipartBody.Builder()
+      .setType(MultipartBody.FORM)
+      .addFormDataPart('file', 'large.bin',
+      RequestBody.create(MediaType.parse('application/octet-stream'), 'X' * (maxContentBytes + 500)))
+      .build()
+    def httpRequest = request(BODY_MULTIPART, 'POST', body).build()
+    def response = client.newCall(httpRequest).execute()
+
+    when:
+    TEST_WRITER.waitForTraces(1)
+
+    then:
+    TEST_WRITER.get(0).any { span ->
+      span.getTag('request.body.files_content') == '[' + 'X' * maxContentBytes + ']'
+    }
+
+    cleanup:
+    response.close()
+  }
+
+  def 'test instrumentation gateway file upload content max files limit'() {
+    setup:
+    assumeTrue(testBodyFilesContent())
+    def maxFilesToInspect = 25
+    def bodyBuilder = new MultipartBody.Builder().setType(MultipartBody.FORM)
+    (1..maxFilesToInspect + 1).each { i ->
+      bodyBuilder.addFormDataPart("file$i", "file${i}.bin",
+        RequestBody.create(MediaType.parse('application/octet-stream'), "content_of_file_$i"))
+    }
+    def httpRequest = request(BODY_MULTIPART, 'POST', bodyBuilder.build()).build()
+    def response = client.newCall(httpRequest).execute()
+
+    when:
+    TEST_WRITER.waitForTraces(1)
+
+    then:
+    TEST_WRITER.get(0).any { span ->
+      def tag = span.getTag('request.body.files_content') as String
+      tag?.contains("content_of_file_$maxFilesToInspect") &&
+        !tag.contains("content_of_file_${maxFilesToInspect + 1}")
+    }
+
+    cleanup:
+    response.close()
+  }
+
   def 'test instrumentation gateway json request body'() {
     setup:
     assumeTrue(testBodyJson())