ESQL: support for mapping-unavailable fields

benchmarks/src/main/java/org/elasticsearch/benchmark/_nightly/esql/QueryPlanningBenchmark.java

@@ -58,6 +58,7 @@
 
 import static java.util.Collections.emptyMap;
 import static org.elasticsearch.xpack.esql.core.type.DataType.TEXT;
+import static org.elasticsearch.xpack.esql.plan.QuerySettings.UNMAPPED_FIELDS;
 
 @Fork(1)
 @Warmup(iterations = 5)
@@ -119,7 +120,8 @@ public void setup() {
                 Map.of(),
                 new EnrichResolution(),
                 InferenceResolution.EMPTY,
-                minimumVersion
+                minimumVersion,
+                UNMAPPED_FIELDS.defaultValue()
             ),
             new Verifier(new Metrics(functionRegistry), new XPackLicenseState(() -> 0L))
         );

x-pack/plugin/esql/qa/testFixtures/src/main/java/org/elasticsearch/xpack/esql/EsqlTestUtils.java

@@ -83,6 +83,7 @@
 import org.elasticsearch.xpack.esql.analysis.AnalyzerSettings;
 import org.elasticsearch.xpack.esql.analysis.EnrichResolution;
 import org.elasticsearch.xpack.esql.analysis.MutableAnalyzerContext;
+import org.elasticsearch.xpack.esql.analysis.UnmappedResolution;
 import org.elasticsearch.xpack.esql.analysis.Verifier;
 import org.elasticsearch.xpack.esql.core.expression.Alias;
 import org.elasticsearch.xpack.esql.core.expression.Attribute;
@@ -220,6 +221,7 @@
 import static org.elasticsearch.xpack.esql.parser.ParserUtils.ParamClassification.IDENTIFIER;
 import static org.elasticsearch.xpack.esql.parser.ParserUtils.ParamClassification.PATTERN;
 import static org.elasticsearch.xpack.esql.parser.ParserUtils.ParamClassification.VALUE;
+import static org.elasticsearch.xpack.esql.plan.QuerySettings.UNMAPPED_FIELDS;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.instanceOf;
@@ -546,6 +548,26 @@ public static MutableAnalyzerContext testAnalyzerContext(
         Map<String, IndexResolution> lookupResolution,
         EnrichResolution enrichResolution,
         InferenceResolution inferenceResolution
+    ) {
+        return testAnalyzerContext(
+            configuration,
+            functionRegistry,
+            indexResolutions,
+            lookupResolution,
+            enrichResolution,
+            inferenceResolution,
+            UNMAPPED_FIELDS.defaultValue()
+        );
+    }
+
+    public static MutableAnalyzerContext testAnalyzerContext(
+        Configuration configuration,
+        EsqlFunctionRegistry functionRegistry,
+        Map<IndexPattern, IndexResolution> indexResolutions,
+        Map<String, IndexResolution> lookupResolution,
+        EnrichResolution enrichResolution,
+        InferenceResolution inferenceResolution,
+        UnmappedResolution unmappedResolution
     ) {
         return new MutableAnalyzerContext(
             configuration,
@@ -554,7 +576,8 @@ public static MutableAnalyzerContext testAnalyzerContext(
             lookupResolution,
             enrichResolution,
             inferenceResolution,
-            randomMinimumVersion()
+            randomMinimumVersion(),
+            unmappedResolution
         );
     }
 
@@ -1212,6 +1235,23 @@ static BytesReference randomTsId() {
         return routingPathFields.buildHash();
     }
 
+    // lifted from org.elasticsearch.http.HttpClientStatsTrackerTests
+    public static String randomizeCase(String s) {
+        final char[] chars = s.toCharArray();
+        for (int i = 0; i < chars.length; i++) {
+            chars[i] = randomizeCase(chars[i]);
+        }
+        return new String(chars);
+    }
+
+    private static char randomizeCase(char c) {
+        return switch (between(1, 3)) {
+            case 1 -> Character.toUpperCase(c);
+            case 2 -> Character.toLowerCase(c);
+            default -> c;
+        };
+    }
+
     public static WildcardLike wildcardLike(Expression left, String exp) {
         return new WildcardLike(EMPTY, left, new WildcardPattern(exp), false);
     }

x-pack/plugin/esql/qa/testFixtures/src/main/java/org/elasticsearch/xpack/esql/analysis/MutableAnalyzerContext.java

@@ -32,9 +32,19 @@ public MutableAnalyzerContext(
         Map<String, IndexResolution> lookupResolution,
         EnrichResolution enrichResolution,
         InferenceResolution inferenceResolution,
-        TransportVersion minimumVersion
+        TransportVersion minimumVersion,
+        UnmappedResolution unmappedResolution
     ) {
-        super(configuration, functionRegistry, indexResolution, lookupResolution, enrichResolution, inferenceResolution, minimumVersion);
+        super(
+            configuration,
+            functionRegistry,
+            indexResolution,
+            lookupResolution,
+            enrichResolution,
+            inferenceResolution,
+            minimumVersion,
+            unmappedResolution
+        );
         this.currentVersion = minimumVersion;
     }