Public API to get list of functions call (#2474)

Issue #2455.

src/libraries/Microsoft.PowerFx.Core/Public/CheckResult.cs

@@ -706,6 +706,11 @@ public CheckContextSummary ApplyGetContextSummary()
 
  return summary;
  }
+
+ public IEnumerable<string> GetFunctionNames()
+ {
+ return ListFunctionVisitor.Run(ApplyParse());
+ }
  }
 
  // Internal interface to ensure that Result objects have a common contract

src/libraries/Microsoft.PowerFx.Core/Syntax/Visitors/ListFunctionVisitor.cs

@@ -0,0 +1,35 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+using System.Collections.Generic;
+
+namespace Microsoft.PowerFx.Syntax
+{
+ internal class ListFunctionVisitor : IdentityTexlVisitor
+ {
+ // FullName --> Name 
+ // Use Fullname as key because it's unique. 
+ private readonly HashSet<string> _functionNames = new HashSet<string>();
+
+ public static IEnumerable<string> Run(ParseResult parse)
+ {
+ var visitor = new ListFunctionVisitor();
+ parse.Root.Accept(visitor);
+ return visitor._functionNames;
+ }
+
+ public override bool PreVisit(CallNode node)
+ {
+ var hasNamespace = node.Head.Namespace.Length > 0;
+
+ var name = node.Head.Name;
+ var fullName = hasNamespace ?
+ node.Head.Namespace + "." + name :
+ name;
+
+ _functionNames.Add(fullName);
+
+ return base.PreVisit(node);
+ }
+ }
+}

src/tests/Microsoft.PowerFx.Core.Tests.Shared/ListFunctionVisitorTests.cs

@@ -0,0 +1,63 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+using System;
+using Xunit;
+
+namespace Microsoft.PowerFx.Core.Tests
+{
+ public class ListFunctionVisitorTests : PowerFxTest
+ {
+ [Theory]
+ [InlineData("Abs(1)", "Abs")]
+ [InlineData("Abs(Abs(Abs(Abs(Abs(1)))))", "Abs")]
+ [InlineData("With({x:Today()}, x+1)", "With,Today")]
+ [InlineData("SomeNameSpace.Foo() + SomeNameSpace.Bar()", "SomeNameSpace.Foo,SomeNameSpace.Bar")]
+ [InlineData("true And true", "")]
+ [InlineData("If(true, Blank(),Error())", "If,Blank,Error")]
+ public void ListFunctionNamesTest(string expression, string expectedNames)
+ {
+ foreach (var textFirst in new bool[] { false, true })
+ {
+ if (textFirst)
+ {
+ expression = $"={expression}";
+ }
+
+ CheckFunctionNames(textFirst, expression, expectedNames);
+ }
+ }
+
+ [Theory]
+ [InlineData("Hello ${Sum(1,Sqrt(2))} world", "Sum,Sqrt")]
+ [InlineData("3 ' {} ${Upper(3+3)} \" ${Lower($\"{7+7}\")}", "Upper,Lower")]
+ public void ListFunctionNamesTextFirstTest(string expression, string expectedNames)
+ {
+ CheckFunctionNames(true, expression, expectedNames);
+ }
+
+ [Fact]
+ public void ListFunctionNamesErrorTest()
+ {
+ var checkResult = new CheckResult(new Engine());
+ Assert.Throws<InvalidOperationException>(() => checkResult.GetFunctionNames());
+ }
+
+ private static void CheckFunctionNames(bool textFirst, string expression, string expectedNames)
+ {
+ var options = new ParserOptions() { TextFirst = textFirst };
+ var engine = new Engine();
+ var check = engine.Check(expression, options);
+ var checkResult = new CheckResult(engine).SetText(expression, options);
+
+ var functionsNames1 = check.GetFunctionNames();
+ var functionsNames2 = checkResult.GetFunctionNames();
+
+ var actualNames1 = string.Join(",", functionsNames1);
+ var actualNames2 = string.Join(",", functionsNames2);
+
+ Assert.Equal(expectedNames, actualNames1);
+ Assert.Equal(expectedNames, actualNames2);
+ }
+ }
+}