Handle missing values in painless (#32207)

Throw an exception for doc['field'].value
if this document is missing a value for the field.

After deprecation changes have been backported to 6.x,
make this a default behaviour in 7.0

Closes #29286

buildSrc/src/main/groovy/org/elasticsearch/gradle/BuildPlugin.groovy

@@ -750,7 +750,6 @@ class BuildPlugin implements Plugin<Project> {
             systemProperty 'tests.task', path
             systemProperty 'tests.security.manager', 'true'
             systemProperty 'jna.nosys', 'true'
-            systemProperty 'es.scripting.exception_for_missing_value', 'true'
             // TODO: remove setting logging level via system property
             systemProperty 'tests.logger.level', 'WARN'
             for (Map.Entry<String, String> property : System.properties.entrySet()) {

docs/painless/painless-getting-started.asciidoc

@@ -123,21 +123,8 @@ GET hockey/_search
 [float]
 ===== Missing values
 
-If you request the value from a field `field` that isn’t in
-the document, `doc['field'].value` for this document returns:
-
-- `0` if a `field` has a numeric datatype (long, double etc.)
-- `false` is a `field` has a boolean datatype
-- epoch date if a `field` has a date datatype
-- `null` if a `field` has a string datatype
-- `null` if a `field` has a geo datatype
-- `""` if a `field` has a binary datatype
-
-IMPORTANT: Starting in 7.0, `doc['field'].value` throws an exception if
-the field is missing in a document. To enable this behavior now,
-set a {ref}/jvm-options.html[`jvm.option`]
-`-Des.scripting.exception_for_missing_value=true` on a node. If you do not enable
-this behavior, a deprecation warning is logged on start up.
+`doc['field'].value` throws an exception if
+the field is missing in a document.
 
 To check if a document is missing a value, you can call
 `doc['field'].size() == 0`.

server/build.gradle

@@ -156,16 +156,6 @@ if (isEclipse) {
 compileJava.options.compilerArgs << "-Xlint:-cast,-deprecation,-rawtypes,-try,-unchecked"
 compileTestJava.options.compilerArgs << "-Xlint:-cast,-deprecation,-rawtypes,-try,-unchecked"
 
-// TODO: remove ScriptDocValuesMissingV6BehaviourTests in 7.0
-additionalTest('testScriptDocValuesMissingV6Behaviour'){
-  include '**/ScriptDocValuesMissingV6BehaviourTests.class'
-  systemProperty 'es.scripting.exception_for_missing_value', 'false'
-}
-test {
-  // these are tested explicitly in separate test tasks
-  exclude '**/*ScriptDocValuesMissingV6BehaviourTests.class'
-}
-
 forbiddenPatterns {
   exclude '**/*.json'
   exclude '**/*.jmx'

server/src/main/java/org/elasticsearch/index/fielddata/ScriptDocValues.java

@@ -29,7 +29,6 @@
 import org.elasticsearch.common.geo.GeoUtils;
 import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.logging.ESLoggerFactory;
-import org.elasticsearch.script.ScriptModule;
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
 import org.joda.time.MutableDateTime;
@@ -126,11 +125,8 @@ protected void resize(int newSize) {
 
         public long getValue() {
             if (count == 0) {
-                if (ScriptModule.EXCEPTION_FOR_MISSING_VALUE) {
-                    throw new IllegalStateException("A document doesn't have a value for a field! " +
-                        "Use doc[<field>].size()==0 to check if a document is missing a field!");
-                }
-                return 0L;
+                throw new IllegalStateException("A document doesn't have a value for a field! " +
+                    "Use doc[<field>].size()==0 to check if a document is missing a field!");
             }
             return values[0];
         }
@@ -172,11 +168,8 @@ public Dates(SortedNumericDocValues in) {
          */
         public ReadableDateTime getValue() {
             if (count == 0) {
-                if (ScriptModule.EXCEPTION_FOR_MISSING_VALUE) {
-                    throw new IllegalStateException("A document doesn't have a value for a field! " +
-                        "Use doc[<field>].size()==0 to check if a document is missing a field!");
-                }
-                return EPOCH;
+                throw new IllegalStateException("A document doesn't have a value for a field! " +
+                    "Use doc[<field>].size()==0 to check if a document is missing a field!");
             }
             return get(0);
         }
@@ -277,11 +270,8 @@ public SortedNumericDoubleValues getInternalValues() {
 
         public double getValue() {
             if (count == 0) {
-                if (ScriptModule.EXCEPTION_FOR_MISSING_VALUE) {
-                    throw new IllegalStateException("A document doesn't have a value for a field! " +
-                        "Use doc[<field>].size()==0 to check if a document is missing a field!");
-                }
-                return 0d;
+               throw new IllegalStateException("A document doesn't have a value for a field! " +
+                   "Use doc[<field>].size()==0 to check if a document is missing a field!");
             }
             return values[0];
         }
@@ -337,11 +327,8 @@ protected void resize(int newSize) {
 
         public GeoPoint getValue() {
             if (count == 0) {
-                if (ScriptModule.EXCEPTION_FOR_MISSING_VALUE) {
-                    throw new IllegalStateException("A document doesn't have a value for a field! " +
+                throw new IllegalStateException("A document doesn't have a value for a field! " +
                         "Use doc[<field>].size()==0 to check if a document is missing a field!");
-                }
-                return null;
             }
             return values[0];
         }
@@ -454,11 +441,8 @@ protected void resize(int newSize) {
 
         public boolean getValue() {
             if (count == 0) {
-                if (ScriptModule.EXCEPTION_FOR_MISSING_VALUE) {
-                    throw new IllegalStateException("A document doesn't have a value for a field! " +
-                        "Use doc[<field>].size()==0 to check if a document is missing a field!");
-                }
-                return false;
+                throw new IllegalStateException("A document doesn't have a value for a field! " +
+                    "Use doc[<field>].size()==0 to check if a document is missing a field!");
             }
             return values[0];
         }
@@ -544,11 +528,8 @@ public String get(int index) {
 
         public String getValue() {
             if (count == 0) {
-                if (ScriptModule.EXCEPTION_FOR_MISSING_VALUE) {
-                    throw new IllegalStateException("A document doesn't have a value for a field! " +
+                throw new IllegalStateException("A document doesn't have a value for a field! " +
                         "Use doc[<field>].size()==0 to check if a document is missing a field!");
-                }
-                return null;
             }
             return get(0);
         }
@@ -572,11 +553,8 @@ public BytesRef get(int index) {
 
         public BytesRef getValue() {
             if (count == 0) {
-                if (ScriptModule.EXCEPTION_FOR_MISSING_VALUE) {
-                    throw new IllegalStateException("A document doesn't have a value for a field! " +
+                throw new IllegalStateException("A document doesn't have a value for a field! " +
                         "Use doc[<field>].size()==0 to check if a document is missing a field!");
-                }
-                return new BytesRef();
             }
             return get(0);
         }

server/src/main/java/org/elasticsearch/script/ScriptModule.java

@@ -31,9 +31,7 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.plugins.ScriptPlugin;
 import org.elasticsearch.search.aggregations.pipeline.movfn.MovingFunctionScript;
-import org.elasticsearch.common.Booleans;
-import org.elasticsearch.common.logging.DeprecationLogger;
-import org.elasticsearch.common.logging.Loggers;
+
 
 /**
  * Manages building {@link ScriptService}.
@@ -64,11 +62,6 @@ public class ScriptModule {
         ).collect(Collectors.toMap(c -> c.name, Function.identity()));
     }
 
-    public static final boolean EXCEPTION_FOR_MISSING_VALUE =
-        Booleans.parseBoolean(System.getProperty("es.scripting.exception_for_missing_value", "false"));
-
-    private static final DeprecationLogger DEPRECATION_LOGGER = new DeprecationLogger(Loggers.getLogger(ScriptModule.class));
-
     private final ScriptService scriptService;
 
     public ScriptModule(Settings settings, List<ScriptPlugin> scriptPlugins) {
@@ -92,10 +85,6 @@ public ScriptModule(Settings settings, List<ScriptPlugin> scriptPlugins) {
                 }
             }
         }
-        if (EXCEPTION_FOR_MISSING_VALUE == false)
-            DEPRECATION_LOGGER.deprecated("Script: returning default values for missing document values is deprecated. " +
-                    "Set system property '-Des.scripting.exception_for_missing_value=true' " +
-                    "to make behaviour compatible with future major versions.");
         scriptService = new ScriptService(settings, Collections.unmodifiableMap(engines), Collections.unmodifiableMap(contexts));
     }