Do not throw errors on unknown types in SearchAfterBuilder (#48147)

* Do not throw errors on unknown types in SearchAfterBuilder

The support for BigInteger and BigDecimal was added for XContent in
https://github.com/elastic/elasticsearch/pull/32888. However the SearchAfterBuilder
xcontent parser doesn't expect them to be present so it throws an AssertionError.
This change fixes this discrepancy by changing the AssertionError into an
IllegalArgumentException that will not cause the node to die when thrown.

Closes #48074

server/src/main/java/org/elasticsearch/search/searchafter/SearchAfterBuilder.java

@@ -243,7 +243,8 @@ public class SearchAfterBuilder implements ToXContentObject, Writeable {
                             break;
 
                         default:
-                            throw new AssertionError("Unknown number type []" + parser.numberType());
+                            throw new IllegalArgumentException("[search_after] does not accept numbers of type ["
+                                + parser.numberType() + "], got " + parser.text());
                     }
                 } else if (token == XContentParser.Token.VALUE_STRING) {
                     values.add(parser.text());

server/src/test/java/org/elasticsearch/search/searchafter/SearchAfterBuilderTests.java

@@ -38,10 +38,13 @@ import org.elasticsearch.search.MultiValueMode;
 import org.elasticsearch.test.ESTestCase;
 
 import java.io.IOException;
+import java.math.BigDecimal;
+import java.math.BigInteger;
 import java.util.Collections;
 
 import static org.elasticsearch.search.searchafter.SearchAfterBuilder.extractSortType;
 import static org.elasticsearch.test.EqualsHashCodeTestUtils.checkEqualsAndHashCode;
+import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 
 public class SearchAfterBuilderTests extends ESTestCase {
@@ -187,6 +190,44 @@ public class SearchAfterBuilderTests extends ESTestCase {
         }
     }
 
+    public void testFromXContentIllegalType() throws Exception {
+        for (XContentType type : XContentType.values()) {
+            // BIG_INTEGER
+            XContentBuilder xContent = XContentFactory.contentBuilder(type);
+            xContent.startObject()
+                .startArray("search_after")
+                .value(new BigInteger("9223372036854776000"))
+                .endArray()
+                .endObject();
+            try (XContentParser parser = createParser(xContent)) {
+                parser.nextToken();
+                parser.nextToken();
+                parser.nextToken();
+                IllegalArgumentException exc = expectThrows(IllegalArgumentException.class, () -> SearchAfterBuilder.fromXContent(parser));
+                assertThat(exc.getMessage(), containsString("BIG_INTEGER"));
+            }
+
+            // BIG_DECIMAL
+            // ignore json and yaml, they parse floating point numbers as floats/doubles
+            if (type == XContentType.JSON || type == XContentType.YAML) {
+                continue;
+            }
+            xContent = XContentFactory.contentBuilder(type);
+            xContent.startObject()
+                .startArray("search_after")
+                    .value(new BigDecimal("9223372036854776003.3"))
+                .endArray()
+                .endObject();
+            try (XContentParser parser = createParser(xContent)) {
+                parser.nextToken();
+                parser.nextToken();
+                parser.nextToken();
+                IllegalArgumentException exc = expectThrows(IllegalArgumentException.class, () -> SearchAfterBuilder.fromXContent(parser));
+                assertThat(exc.getMessage(), containsString("BIG_DECIMAL"));
+            }
+        }
+    }
+
     public void testWithNullArray() throws Exception {
         SearchAfterBuilder builder = new SearchAfterBuilder();
         try {