Fix variable argument functions in expressions

204ef7a708466d8739e5dcbfbc4794b57cabab0f

Co-Authored-By: Octavia Togami <2093023+octylFractal@users.noreply.github.com>

worldedit-core/src/main/java/com/sk89q/worldedit/command/UtilityCommands.java

@@ -678,7 +678,11 @@ public class UtilityCommands {
         try {
             expression = Expression.compile(String.join(" ", input));
         } catch (ExpressionException e) {
-            actor.printError(TranslatableComponent.of("worldedit.calc.invalid", TextComponent.of(String.join(" ", input))));
+            actor.printError(TranslatableComponent.of(
+                    "worldedit.calc.invalid.with-error",
+                    TextComponent.of(String.join(" ", input)),
+                    TextComponent.of(e.getMessage())
+            ));
             return;
         }
         WorldEditAsyncCommandBuilder.createAndSendMessage(actor, () -> {

worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/ExpressionHelper.java

@@ -65,9 +65,22 @@ public class ExpressionHelper {
         Set<MethodHandle> matchingFns = functions.getMap().get(fnName);
         check(!matchingFns.isEmpty(), ctx, "Unknown function '" + fnName + "'");
         for (MethodHandle function : matchingFns) {
+            if (function.isVarargsCollector()) {
+                int nParams = function.type().parameterCount();
+                // last param is the array, turn that varargs
+                int keptParams = nParams - 1;
+                function = function.asCollector(
+                        // collect into the last array
+                        function.type().parameterType(nParams - 1),
+                        // collect the variable args (args over kept)
+                        ctx.args.size() - keptParams
+                );
+                // re-wrap it for the inner arguments
+                function = function.asType(function.type().wrap());
+            }
             MethodType type = function.type();
             // Validate argc if not varargs
-            if (!function.isVarargsCollector() && type.parameterCount() != ctx.args.size()) {
+            if (type.parameterCount() != ctx.args.size()) {
                 // skip non-matching function
                 continue;
             }

worldedit-core/src/main/java/com/sk89q/worldedit/internal/expression/Functions.java

@@ -63,6 +63,7 @@ public final class Functions {
     }
 
     private static MethodHandle clean(MethodHandle handle) {
+        boolean wasVarargs = handle.isVarargsCollector();
         // box it all first
         handle = handle.asType(handle.type().wrap());
         if (handle.type().returnType() != Double.class) {
@@ -72,6 +73,12 @@ public final class Functions {
             handle = handle.asType(handle.type().changeReturnType(Number.class));
             handle = filterReturnValue(handle, DOUBLE_VALUE);
         }
+        // return vararg-ity
+        if (wasVarargs) {
+            handle = handle.asVarargsCollector(
+                    handle.type().parameterType(handle.type().parameterCount() - 1)
+            );
+        }
         return handle;
     }
 

worldedit-core/src/main/resources/lang/strings.json

@@ -342,6 +342,7 @@
     "worldedit.remove.removed": "{0} entities have been marked for removal.",
     "worldedit.remove.explain-all": "Use -1 to remove all entities in loaded chunks",
     "worldedit.calc.invalid": "'{0}' could not be parsed as a valid expression",
+    "worldedit.calc.invalid.with-error": "'{0}' could not be parsed as a valid expression: '{1}'",
 
     "worldedit.paste.pasted": "The clipboard has been pasted at {0}",
     "worldedit.paste.selected": "Selected clipboard paste region.",

worldedit-core/src/test/java/com/sk89q/worldedit/internal/expression/ExpressionTest.java

@@ -51,6 +51,9 @@ class ExpressionTest extends BaseExpressionTest {
             // check functions
             testCase("sin(5)", sin(5)),
             testCase("atan2(3, 4)", atan2(3, 4)),
+            testCase("min(1, 2)", 1),
+            testCase("max(1, 2)", 2),
+            testCase("max(1, 2, 3, 4, 5)", 5),
             // check conditionals
             testCase("0 || 5", 5),
             testCase("2 || 5", 2),