From 7569e863b3fe60e44ac9e958e54c3fc197cce3cc Mon Sep 17 00:00:00 2001
From: Nadiia Padalka <35704032+nadiapadalka@users.noreply.github.com>
Date: Wed, 25 Oct 2023 14:09:54 +0300
Subject: [PATCH] add logic for optional chaining (#21)

* add logic for optional chaining

* remove console log

* format doc

* fix test

* fix uts
---
 src/parser/Parser.ts                    |  3 +++
 test/e2e/resources/multi-file/test1.brs | 13 ++++++++++
 test/parser/expression/Indexing.test.js | 32 ++++++++++++++++++++++++-
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/src/parser/Parser.ts b/src/parser/Parser.ts
index 32c96334c..677f60784 100644
--- a/src/parser/Parser.ts
+++ b/src/parser/Parser.ts
@@ -534,6 +534,7 @@ export class Parser {
                     Lexeme.Newline,
                     Lexeme.Colon,
                     Lexeme.Eof,
+                    Lexeme.Identifier,
                     ...additionalterminators
                 );
             }
@@ -1415,6 +1416,8 @@ export class Parser {
             while (true) {
                 if (match(Lexeme.LeftParen)) {
                     expr = finishCall(expr);
+                } else if (match(Lexeme.Print)) {
+                    // doing nothing as invalid check was before
                 } else if (match(Lexeme.LeftSquare)) {
                     indexedGet();
                 } else if (match(Lexeme.Dot)) {
diff --git a/test/e2e/resources/multi-file/test1.brs b/test/e2e/resources/multi-file/test1.brs
index 7137075d1..39a633c5d 100644
--- a/test/e2e/resources/multi-file/test1.brs
+++ b/test/e2e/resources/multi-file/test1.brs
@@ -2,6 +2,7 @@ sub Main()
     print("function in same file: " + sameFileFunc())
     print("function in different file: " + differentFileFunc())
     print("function with dependency: " + dependentFunc())
+    print("result" + testOptionalChaining())
 end sub
 
 function sameFileFunc()
@@ -11,3 +12,15 @@ end function
 function dependencyFunc()
     return "from dependencyFunc()"
 end function
+
+function testOptionalChaining()
+    result = responseData?.data.metricsData?.addOnsStepStart
+    responseData = {
+        data:{
+            metricsData:{
+                addOnsStepStart : "print"
+            }
+        }
+    }
+    return result
+end function
diff --git a/test/parser/expression/Indexing.test.js b/test/parser/expression/Indexing.test.js
index 4e3c5ac60..73037c596 100644
--- a/test/parser/expression/Indexing.test.js
+++ b/test/parser/expression/Indexing.test.js
@@ -1,6 +1,6 @@
 const brs = require("../../../lib");
 const { Lexeme } = brs.lexer;
-const { Int32 } = brs.types;
+const { Int32, BrsInvalid } = brs.types;
 
 const { token, identifier, EOF } = require("../ParserTests");
 
@@ -28,6 +28,36 @@ describe("parser indexing", () => {
             expect(statements).toMatchSnapshot();
         });
 
+        test("Expression with identifier", () => {
+            let { statements, errors } = parser.parse([
+                identifier("_"),
+                token(Lexeme.Equal, "="),
+                identifier("bar"),
+                token(Lexeme.Print, "?"),
+                token(Lexeme.Dot, "."),
+                identifier("foo"),
+                EOF,
+            ]);
+            expect(errors).toEqual([]);
+            expect(statements).toBeDefined();
+            expect(statements).not.toBeNull();
+        });
+
+        test("Expression with invalid", () => {
+            let { statements, errors } = parser.parse([
+                identifier("_"),
+                token(Lexeme.Equal, "="),
+                token(Lexeme.Invalid, "invalid", BrsInvalid.Instance),
+                token(Lexeme.Print, "?"),
+                token(Lexeme.Dot, "."),
+                identifier("bar"),
+                EOF,
+            ]);
+            expect(errors).toEqual([]);
+            expect(statements).toBeDefined();
+            expect(statements).not.toBeNull();
+        });
+
         test("bracketed", () => {
             let { statements, errors } = parser.parse([
                 identifier("_"),