ESQL: Rework FieldExtractorIT's pragmas (#127117)

This reworks the way `FieldExtractorIT` requests fields to be loaded.
Previously it used pragmas and would skip itself if it wasn't a unit
test. This removes that behavior and sends pragmas but also sends the
`accept_pragma_risks` option which is used in production releases to
allow pragmas - it's especially useful for testing. This *should* make
the tests more consistent.

Closes #127100

Author: nik9000

x-pack/plugin/esql/qa/server/mixed-cluster/src/javaRestTest/java/org/elasticsearch/xpack/esql/qa/mixed/FieldExtractorIT.java

@@ -12,6 +12,7 @@
 import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.test.TestClustersThreadFilter;
 import org.elasticsearch.test.cluster.ElasticsearchCluster;
+import org.elasticsearch.test.cluster.util.Version;
 import org.elasticsearch.xpack.esql.qa.rest.FieldExtractorTestCase;
 import org.hamcrest.Matcher;
 import org.junit.ClassRule;
@@ -40,4 +41,16 @@ protected Matcher<Integer> pidMatcher() {
         return preference == MappedFieldType.FieldExtractPreference.STORED ? anyOf(equalTo(111), nullValue()) : nullValue(Integer.class);
     }
 
+    @Override
+    protected void canUsePragmasOk() {
+        String bwc = System.getProperty("tests.old_cluster_version");
+        if (bwc == null) {
+            bwc = System.getProperty("tests.serverless.bwc_stack_version");
+        }
+        if (bwc == null) {
+            throw new AssertionError("can't find bwc version");
+        }
+        Version oldVersion = Version.fromString(bwc);
+        assumeTrue("pragma ok not supported", oldVersion.onOrAfter("8.16.0"));
+    }
 }

x-pack/plugin/esql/qa/server/multi-node/src/javaRestTest/java/org/elasticsearch/xpack/esql/qa/multi_node/FieldExtractorIT.java

@@ -28,4 +28,9 @@ public FieldExtractorIT(MappedFieldType.FieldExtractPreference preference) {
     protected String getTestRestCluster() {
         return cluster.getHttpAddresses();
     }
+
+    @Override
+    protected void canUsePragmasOk() {
+        // always ok
+    }
 }

x-pack/plugin/esql/qa/server/single-node/src/javaRestTest/java/org/elasticsearch/xpack/esql/qa/single_node/FieldExtractorIT.java

@@ -28,4 +28,9 @@ public FieldExtractorIT(MappedFieldType.FieldExtractPreference preference) {
     protected String getTestRestCluster() {
         return cluster.getHttpAddresses();
     }
+
+    @Override
+    protected void canUsePragmasOk() {
+        // always can use
+    }
 }

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/FieldExtractorTestCase.java

@@ -10,7 +10,6 @@
 import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 
 import org.apache.http.util.EntityUtils;
-import org.elasticsearch.Build;
 import org.elasticsearch.Version;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
@@ -35,7 +34,6 @@
 import org.elasticsearch.xpack.esql.core.type.DataType;
 import org.elasticsearch.xpack.esql.plugin.QueryPragmas;
 import org.hamcrest.Matcher;
-import org.junit.Before;
 
 import java.io.IOException;
 import java.math.BigDecimal;
@@ -83,17 +81,6 @@ public static List<Object[]> args() throws Exception {
 
     protected FieldExtractorTestCase(MappedFieldType.FieldExtractPreference preference) {
         this.preference = preference;
-        if (preference != null) {
-            assumeTrue("Requires pragma", Build.current().isSnapshot());
-        }
-    }
-
-    @Before
-    public void notOld() {
-        assumeTrue(
-            "support changed pretty radically in 8.12 so we don't test against 8.11",
-            getCachedNodesVersions().stream().allMatch(v -> Version.fromString(v).onOrAfter(Version.V_8_12_0))
-        );
     }
 
     public void testTextField() throws IOException {
@@ -1784,10 +1771,14 @@ private String deyaml(String err) {
     private Map<String, Object> runEsql(String query) throws IOException {
         RestEsqlTestCase.RequestObjectBuilder request = new RestEsqlTestCase.RequestObjectBuilder().query(query);
         if (preference != null) {
+            canUsePragmasOk();
             request = request.pragmas(
                 Settings.builder().put(QueryPragmas.FIELD_EXTRACT_PREFERENCE.getKey(), preference.toString()).build()
             );
+            request.pragmasOk();
         }
         return runEsqlSync(request);
     }
+
+    protected abstract void canUsePragmasOk();
 }

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/RestEsqlTestCase.java

@@ -178,6 +178,14 @@ public RequestObjectBuilder keepOnCompletion(boolean value) throws IOException {
             return this;
         }
 
+        /**
+         * Allow sending pragmas even in non-snapshot builds.
+         */
+        public RequestObjectBuilder pragmasOk() throws IOException {
+            builder.field("accept_pragma_risks", true);
+            return this;
+        }
+
         Boolean keepOnCompletion() {
             return keepOnCompletion;
         }