Tweak tests

Author: svilen-mihaylov-elastic

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search.highlight/30_max_analyzed_offset.yml

@@ -115,7 +115,7 @@ setup:
   - match: {hits.hits.0.highlight.field2.0: "The quick brown <em>fox</em> went to the forest and saw another fox."}
 
 ---
-"Plain highlighter with max_analyzed_offset < 0 should FAIL":
+"Plain highlighter with max_analyzed_offset < -1 should FAIL":
 
   - requires:
       cluster_features: ["gte_v7.12.0"]
@@ -130,4 +130,4 @@ setup:
   - match: { status: 400 }
   - match: { error.root_cause.0.type: "x_content_parse_exception" }
   - match: { error.caused_by.type: "illegal_argument_exception" }
-  - match: { error.caused_by.reason: "[max_analyzed_offset] must be a positive integer" }
+  - match: { error.caused_by.reason: "[max_analyzed_offset] must be an integer >= -1" }

server/src/main/java/org/elasticsearch/search/fetch/subphase/highlight/AbstractHighlighterBuilder.java

@@ -565,6 +565,9 @@ public Integer phraseLimit() {
      */
     @SuppressWarnings("unchecked")
     public HB maxAnalyzedOffset(Integer maxAnalyzedOffset) {
+        if (maxAnalyzedOffset != null && maxAnalyzedOffset < -1) {
+            throw new IllegalArgumentException("[" + MAX_ANALYZED_OFFSET_FIELD + "] must be an integer >= -1");
+        }
         this.maxAnalyzedOffset = maxAnalyzedOffset;
         return (HB) this;
     }

server/src/test/java/org/elasticsearch/search/fetch/subphase/highlight/HighlightBuilderTests.java

@@ -580,7 +580,7 @@ public void testInvalidMaxAnalyzedOffset() throws IOException {
             "{ \"max_analyzed_offset\" : " + randomIntBetween(-100, 0) + "}"
         );
         assertThat(e.getMessage(), containsString("[highlight] failed to parse field [" + MAX_ANALYZED_OFFSET_FIELD.toString() + "]"));
-        assertThat(e.getCause().getMessage(), containsString("[max_analyzed_offset] must be a positive integer"));
+        assertThat(e.getCause().getMessage(), containsString("[max_analyzed_offset] must be an integer >= -1"));
     }
 
     /**