Fix scope info for AddColumns / Search functions

src/libraries/Microsoft.PowerFx.Core/Texl/Builtins/AddColumns.cs

@@ -34,7 +34,7 @@ public AddColumnsFunction()
         {
             // AddColumns(source, name, valueFunc, name, valueFunc, ..., name, valueFunc, ...)
             SignatureConstraint = new SignatureConstraint(omitStartIndex: 5, repeatSpan: 2, endNonRepeatCount: 0, repeatTopLength: 9);
-            ScopeInfo = new FunctionScopeInfo(this, canBeCreatedByRecord: true);
+            ScopeInfo = new FunctionScopeInfo(this, canBeCreatedByRecord: true, appliesToArgument: (argIndex) => argIndex > 1 && (argIndex % 2) == 0);
         }
 
         public override IEnumerable<TexlStrings.StringGetter[]> GetSignatures()

src/libraries/Microsoft.PowerFx.Core/Texl/Builtins/RenameColumns.cs

@@ -30,7 +30,7 @@ public RenameColumnsFunction()
         {
             // RenameColumns(source, oldName, newName, oldName, newName, ..., oldName, newName, ...)
             SignatureConstraint = new SignatureConstraint(omitStartIndex: 5, repeatSpan: 2, endNonRepeatCount: 0, repeatTopLength: 9);
-            ScopeInfo = new FunctionScopeInfo(this, canBeCreatedByRecord: true);
+            ScopeInfo = new FunctionScopeInfo(this, canBeCreatedByRecord: true, appliesToArgument: (argIndex) => argIndex % 2 == 1);
         }
 
         public override IEnumerable<TexlStrings.StringGetter[]> GetSignatures()

src/libraries/Microsoft.PowerFx.Core/Texl/Builtins/Search.cs

@@ -33,7 +33,7 @@ internal sealed class SearchFunction : FunctionWithTableInput
         public SearchFunction()
             : base("Search", TexlStrings.AboutSearch, FunctionCategories.Table, DType.EmptyTable, 0, 3, int.MaxValue, DType.EmptyTable, DType.String, DType.String)
         {
-            ScopeInfo = new FunctionScopeInfo(this);
+            ScopeInfo = new FunctionScopeInfo(this, appliesToArgument: (argIndex) => argIndex > 1);
         }
 
         public override ParamIdentifierStatus GetIdentifierParamStatus(Features features, int index)

src/tests/Microsoft.PowerFx.Core.Tests/FunctionTests.cs

@@ -294,6 +294,31 @@ public void TextFunctionSet_Remove2()
             Assert.Empty(tfs.WithNamespace(DPath.Root));
         }
 
+        [Fact]
+        public void TestScopeArguments()
+        {
+            for (int i = 0; i < 10; i++)
+            {
+                // AddColumns(<table>, <new column>, <expression using scope from arg0>[, <new column 2>, <expression using scope from arg0>, ...]
+                Assert.Equal(i > 0 && i % 2 == 0, BuiltinFunctionsCore.AddColumns.ScopeInfo.AppliesToArgument(i));
+
+                // RenameColumns(<table>, <old column from arg0>, <new column>[, <old column from arg0>, <new column 2>, ...]
+                Assert.Equal(i % 2 == 1, BuiltinFunctionsCore.RenameColumns.ScopeInfo.AppliesToArgument(i));
+
+                // ShowColumns(<table>, <column from arg0>, <column from arg0>, ...)
+                Assert.Equal(i > 0, BuiltinFunctionsCore.ShowColumns.ScopeInfo.AppliesToArgument(i));
+
+                // DropColumns(<table>, <column from arg0>, <column from arg0>, ...)
+                Assert.Equal(i > 0, BuiltinFunctionsCore.DropColumns.ScopeInfo.AppliesToArgument(i));
+
+                // Search(<table>, <text arg>, <column from arg0>, <column from arg0>, ...)
+                Assert.Equal(i > 1, BuiltinFunctionsCore.Search.ScopeInfo.AppliesToArgument(i));
+
+                // ShowColumns(<table>, <column from arg0>, <sort order>, <column from arg0>, <sort order>, ...)
+                Assert.Equal(i % 2 == 1, BuiltinFunctionsCore.SortByColumns.ScopeInfo.AppliesToArgument(i));
+            }
+        }
+
         private class TestTexlFunction : TexlFunction
         {
             private readonly int _requiredEnums = 0;