Add decay tests to VerifierTests checking nullability of all function arguments

Author: timgrein

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/EsqlCapabilities.java

@@ -1289,7 +1289,12 @@ public enum Cap {
         /**
          * Support for the options field of CATEGORIZE.
          */
-        CATEGORIZE_OPTIONS;
+        CATEGORIZE_OPTIONS,
+
+        /**
+         * Decay function for custom scoring
+         */
+        DECAY_FUNCTION;
 
         private final boolean enabled;
 

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/fulltext/Decay.java

@@ -177,38 +177,38 @@ protected TypeResolution resolveType() {
 
         // Spatial decay
         if (isSpatialPoint(valueDataType)) {
-            TypeResolution originResolution = isType(origin, DataType::isSpatialPoint, sourceText(), SECOND, "spatial point");
+            TypeResolution originResolution = isNotNull(origin, sourceText(), SECOND).and(isType(origin, DataType::isSpatialPoint, sourceText(), SECOND, "spatial point"));
             if (originResolution.unresolved()) {
                 return originResolution;
             }
 
             // For a spatial decay the scale should be a distance unit string (e.g. "100km")
-            TypeResolution scaleResolution = isType(scale, DataType::isString, sourceText(), THIRD, "keyword or text");
+            TypeResolution scaleResolution = isNotNull(scale, sourceText(), THIRD).and(isType(scale, DataType::isString, sourceText(), THIRD, "keyword or text"));
             if (scaleResolution.unresolved()) {
                 return scaleResolution;
             }
         }
         // Temporal decay
         else if (isMillisOrNanos(valueDataType)) {
-            TypeResolution originResolution = isType(origin, DataType::isMillisOrNanos, sourceText(), SECOND, "datetime or date_nanos");
+            TypeResolution originResolution = isNotNull(origin, sourceText(), SECOND).and(isType(origin, DataType::isMillisOrNanos, sourceText(), SECOND, "datetime or date_nanos"));
             if (originResolution.unresolved()) {
                 return originResolution;
             }
 
             // For a temporal decay the scale should be a time value string (e.g. "5h")
-            TypeResolution scaleResolution = isType(scale, DataType::isString, sourceText(), THIRD, "date_period or time_duration");
+            TypeResolution scaleResolution = isNotNull(scale, sourceText(), THIRD).and(isType(scale, DataType::isString, sourceText(), THIRD, "date_period or time_duration"));
             if (scaleResolution.unresolved()) {
                 return scaleResolution;
             }
         }
         // Numeric decay
         else {
-            TypeResolution originResolution = isNumeric(origin, sourceText(), SECOND);
+            TypeResolution originResolution = isNotNull(origin, sourceText(), SECOND).and(isNumeric(origin, sourceText(), SECOND));
             if (originResolution.unresolved()) {
                 return originResolution;
             }
 
-            TypeResolution scaleResolution = isNumeric(scale, sourceText(), THIRD);
+            TypeResolution scaleResolution = isNotNull(scale, sourceText(), THIRD).and(isNumeric(scale, sourceText(), THIRD));
             if (scaleResolution.unresolved()) {
                 return scaleResolution;
             }

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/VerifierTests.java

@@ -2346,6 +2346,43 @@ public void testRemoteLookupJoinIsDisabled() {
 
     }
 
+    public void testDecayFunctionNullArgs(){
+        assumeTrue("Decay function not enabled", EsqlCapabilities.Cap.DECAY_FUNCTION.isEnabled());
+
+        // First arg cannot be null
+        assertEquals(
+            "2:23: first argument of [decay(null, origin, scale, 0, 0.5, \"linear\")] cannot be null, received [null]",
+            error("row origin = 10, scale = 10\n"
+                + "| eval decay_result = decay(null, origin, scale, 0, 0.5, \"linear\")")
+        );
+
+        // Second arg cannot be null
+        assertEquals(
+            "2:23: second argument of [decay(value, null, scale, 0, 0.5, \"linear\")] cannot be null, received [null]",
+            error("row value = 10, scale = 10\n"
+                + "| eval decay_result = decay(value, null, scale, 0, 0.5, \"linear\")")
+        );
+
+        // Third arg cannot be null
+        assertEquals(
+            "2:23: third argument of [decay(value, origin, null, 0, 0.5, \"linear\")] cannot be null, received [null]",
+            error("row value = 10, origin = 10\n"
+                + "| eval decay_result = decay(value, origin, null, 0, 0.5, \"linear\")")
+        );
+
+        // Fourth arg can be null
+        query("row value = 10, origin = 10, scale = 10\n"
+            + "| eval decay_result = decay(value, origin, scale, null, 0.5, \"linear\")");
+
+        // Fifth arg can be null
+        query("row value = 10, origin = 10, scale = 10\n"
+            + "| eval decay_result = decay(value, origin, scale, 0, null, \"linear\")");
+
+        // Sixth arg can be null
+        query("row value = 10, origin = 10, scale = 10\n"
+            + "| eval decay_result = decay(value, origin, scale, 0, 0.5, null)");
+    }
+
     private void checkFullTextFunctionsInStats(String functionInvocation) {
         query("from test | stats c = max(id) where " + functionInvocation, fullTextAnalyzer);
         query("from test | stats c = max(id) where " + functionInvocation + " or length(title) > 10", fullTextAnalyzer);