Make LOOKUP JOIN types table more compact

Author: craigtaverner

docs/reference/query-languages/esql/_snippets/commands/types/lookup-join.md

@@ -2,76 +2,20 @@
 
 **Supported types**
 
-| main | join | 
+| field from the left index | field from the lookup index | 
 | --- | --- | 
-| boolean | boolean | 
-| byte | byte | 
-| byte | double | 
-| byte | float | 
-| byte | half_float | 
-| byte | integer | 
-| byte | long | 
-| byte | scaled_float | 
-| byte | short | 
-| date | date | 
-| date_nanos | date_nanos | 
-| double | byte | 
-| double | double | 
-| double | float | 
-| double | half_float | 
-| double | integer | 
-| double | long | 
-| double | scaled_float | 
-| double | short | 
-| float | byte | 
-| float | double | 
-| float | float | 
-| float | half_float | 
-| float | integer | 
-| float | long | 
-| float | scaled_float | 
-| float | short | 
-| half_float | byte | 
-| half_float | double | 
-| half_float | float | 
-| half_float | half_float | 
-| half_float | integer | 
-| half_float | long | 
-| half_float | scaled_float | 
-| half_float | short | 
-| integer | byte | 
-| integer | double | 
-| integer | float | 
-| integer | half_float | 
-| integer | integer | 
-| integer | long | 
-| integer | scaled_float | 
-| integer | short | 
-| ip | ip | 
-| keyword | keyword | 
-| long | byte | 
-| long | double | 
-| long | float | 
-| long | half_float | 
-| long | integer | 
-| long | long | 
-| long | scaled_float | 
-| long | short | 
-| scaled_float | byte | 
-| scaled_float | double | 
-| scaled_float | float | 
-| scaled_float | half_float | 
-| scaled_float | integer | 
-| scaled_float | long | 
-| scaled_float | scaled_float | 
-| scaled_float | short | 
-| short | byte | 
-| short | double | 
-| short | float | 
-| short | half_float | 
-| short | integer | 
-| short | long | 
-| short | scaled_float | 
-| short | short | 
-| text | keyword | 
+| boolean | boolean |
+| byte | half_float, float, double, scaled_float, byte, short, integer, long |
+| date | date |
+| date_nanos | date_nanos |
+| double | half_float, float, double, scaled_float, byte, short, integer, long |
+| float | half_float, float, double, scaled_float, byte, short, integer, long |
+| half_float | half_float, float, double, scaled_float, byte, short, integer, long |
+| integer | half_float, float, double, scaled_float, byte, short, integer, long |
+| ip | ip |
+| keyword | keyword |
+| long | half_float, float, double, scaled_float, byte, short, integer, long |
+| scaled_float | half_float, float, double, scaled_float, byte, short, integer, long |
+| short | half_float, float, double, scaled_float, byte, short, integer, long |
+| text | keyword |
 

x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/action/LookupJoinTypesIT.java

@@ -768,8 +768,8 @@ private boolean isValidDataType(DataType dataType) {
 
     private static void saveJoinTypes(Supplier<Map<List<DataType>, DataType>> signatures) throws Exception {
         ArrayList<EsqlFunctionRegistry.ArgSignature> args = new ArrayList<>();
-        args.add(new EsqlFunctionRegistry.ArgSignature("main", null, "Field from the main index", false, false));
-        args.add(new EsqlFunctionRegistry.ArgSignature("join", null, "Field from the join index", false, false));
+        args.add(new EsqlFunctionRegistry.ArgSignature("field from the left index", null, null, false, false));
+        args.add(new EsqlFunctionRegistry.ArgSignature("field from the lookup index", null, null, false, false));
         DocsV3Support.CommandsDocsSupport docs = new DocsV3Support.CommandsDocsSupport(
             "lookup-join",
             LookupJoinTypesIT.class,

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/DocsV3Support.java

@@ -64,6 +64,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.TreeMap;
 import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.regex.Matcher;
@@ -311,7 +312,7 @@ public License.OperationMode invoke(List<DataType> fieldTypes) throws Exception
     protected final String name;
     protected final FunctionDefinition definition;
     protected final Logger logger;
-    private final Supplier<Map<List<DataType>, DataType>> signatures;
+    protected final Supplier<Map<List<DataType>, DataType>> signatures;
     private TempFileWriter tempFileWriter;
     private final LicenseRequirementChecker licenseChecker;
 
@@ -930,6 +931,47 @@ void renderKibanaCommandDefinition() throws Exception {
                 writeToTempKibanaDir("definition", "json", rendered);
             }
         }
+
+        @Override
+        void renderTypes(String name, List<EsqlFunctionRegistry.ArgSignature> args) throws IOException {
+            assert args.size() == 2;
+            StringBuilder header = new StringBuilder("| ");
+            StringBuilder separator = new StringBuilder("| ");
+            List<String> argNames = args.stream().map(EsqlFunctionRegistry.ArgSignature::name).toList();
+            for (String arg : argNames) {
+                header.append(arg).append(" | ");
+                separator.append("---").append(" | ");
+            }
+
+            Map<String, List<String>> compactedTable = new TreeMap<>();
+            for (Map.Entry<List<DataType>, DataType> sig : this.signatures.get().entrySet()) {
+                if (shouldHideSignature(sig.getKey(), sig.getValue())) {
+                    continue;
+                }
+                String mainType = sig.getKey().getFirst().esNameIfPossible();
+                String secondaryType = sig.getKey().get(1).esNameIfPossible();
+                List<String> secondaryTypes = compactedTable.computeIfAbsent(mainType, (k) -> new ArrayList<>());
+                secondaryTypes.add(secondaryType);
+            }
+
+            List<String> table = new ArrayList<>();
+            for (Map.Entry<String, List<String>> sig : compactedTable.entrySet()) {
+                String row = "| " + sig.getKey() + " | " + String.join(", ", sig.getValue()) + " |";
+                table.add(row);
+            }
+            Collections.sort(table);
+            if (table.isEmpty()) {
+                logger.info("Warning: No table of types generated for [{}]", name);
+                return;
+            }
+
+            String rendered = DOCS_WARNING + """
+                **Supported types**
+
+                """ + header + "\n" + separator + "\n" + String.join("\n", table) + "\n\n";
+            logger.info("Writing function types for [{}]:\n{}", name, rendered);
+            writeToTempSnippetsDir("types", rendered);
+        }
     }
 
     protected String buildFunctionSignatureSvg() throws IOException {