fix(interp): Preventing multiple calls for dot-chained methods (#22)

* Preventing multiple calls for dot-chained methods

* Fixed `prettier` issue

.gitignore

@@ -3,4 +3,5 @@ lib/
 types/
 node_modules/
 .vscode/
-coverage/
+coverage/
+.DS_Store

src/interpreter/index.ts

@@ -74,6 +74,7 @@ Object.freeze(defaultExecutionOptions);
 
 export class Interpreter implements Expr.Visitor<BrsType>, Stmt.Visitor<BrsType> {
     private _environment = new Environment();
+    private _lastDotGetAA: RoAssociativeArray = this._environment.getRootM();
     private coverageCollector: CoverageCollector | null = null;
     private _manifest: PP.Manifest | undefined;
 
@@ -1093,21 +1094,27 @@ export class Interpreter implements Expr.Visitor<BrsType>, Stmt.Visitor<BrsType>
                     expression.callee instanceof Expr.DottedGet ||
                     expression.callee instanceof Expr.IndexedGet
                 ) {
-                    let maybeM = this.evaluate(expression.callee.obj);
-                    maybeM = isBoxable(maybeM) ? maybeM.box() : maybeM;
-
-                    if (maybeM.kind === ValueKind.Object) {
-                        if (maybeM instanceof RoAssociativeArray) {
-                            mPointer = maybeM;
-                        }
+                    if (expression.callee.obj instanceof Expr.Call) {
+                        mPointer = this._lastDotGetAA;
                     } else {
-                        return this.addError(
-                            new BrsError(
-                                "Attempted to retrieve a function from a primitive value",
-                                expression.closingParen.location
-                            )
-                        );
+                        let maybeM = this.evaluate(expression.callee.obj);
+                        maybeM = isBoxable(maybeM) ? maybeM.box() : maybeM;
+
+                        if (maybeM.kind === ValueKind.Object) {
+                            if (maybeM instanceof RoAssociativeArray) {
+                                mPointer = maybeM;
+                            }
+                        } else {
+                            return this.addError(
+                                new BrsError(
+                                    "Attempted to retrieve a function from a primitive value",
+                                    expression.closingParen.location
+                                )
+                            );
+                        }
                     }
+                } else {
+                    this._lastDotGetAA = this.environment.getRootM();
                 }
 
                 return this.inSubEnv((subInterpreter) => {
@@ -1182,6 +1189,9 @@ export class Interpreter implements Expr.Visitor<BrsType>, Stmt.Visitor<BrsType>
 
         if (isIterable(source)) {
             try {
+                if (source instanceof RoAssociativeArray) {
+                    this._lastDotGetAA = source;
+                }
                 return source.get(new BrsString(expression.name.text));
             } catch (err: any) {
                 return this.addError(new BrsError(err.message, expression.name.location));

test/e2e/Syntax.test.js

@@ -201,9 +201,8 @@ describe("end to end syntax", () => {
             "run",
             "stop",
             "then",
-            "promise-like resolved to 'foo'",
             "Hello from line ",
-            "18",
+            "14",
         ]);
     });
 
@@ -216,4 +215,14 @@ describe("end to end syntax", () => {
             "14", // arr = [13]: arr[0]++
         ]);
     });
+
+    test("dot-chaining.brs", async () => {
+        await execute([resourceFile("dot-chaining.brs")], outputStreams);
+
+        expect(allArgs(outputStreams.stdout.write).filter((arg) => arg !== "\n")).toEqual([
+            "removed number '3' from array, remaining 2",
+            "promise-like resolved to 'foo'",
+            "optional chaining works",
+        ]);
+    });
 });

test/e2e/resources/dot-chaining.brs

@@ -0,0 +1,36 @@
+sub main()
+    a = [" 1 ", " 2 ", " 3 "]
+    b = a.pop().trim().toInt()
+    print "removed number '" + b.toStr() + "' from array, remaining " + a.count().toStr()
+    m.__result = "bad"
+    immediatePromise("foo").then(sub(result)
+        print "promise-like resolved to '" + result + "'"
+    end sub)
+    print "optional chaining " + testOptionalChaining()
+end sub
+
+' A simple promise-like function that immediately resolves to the provided value.
+' You probably don't want to use it in production.
+' @param {*} val the value this promise-like should immediately resolve to
+' @returns {AssociativeArray} an associative array contianing a `then` property, used to chain
+'                             promise-like constructs.
+function immediatePromise(val as dynamic) as object
+    return {
+        __result: val
+        then: sub(resolved as function)
+            resolved(m.__result)
+        end sub
+    }
+end function
+
+function testOptionalChaining()
+    responseData = {
+        data:{
+            metricsData:{
+                addOnsStepStart : "works"
+            }
+        }
+    }
+    result = responseData?.data.metricsData?.addOnsStepStart
+    return result
+end function

test/e2e/resources/multi-file/test1.brs

@@ -2,7 +2,6 @@ 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()
@@ -13,14 +12,3 @@ function dependencyFunc()
     return "from dependencyFunc()"
 end function
 
-function testOptionalChaining()
-    result = responseData?.data.metricsData?.addOnsStepStart
-    responseData = {
-        data:{
-            metricsData:{
-                addOnsStepStart : "print"
-            }
-        }
-    }
-    return result
-end function

test/e2e/resources/reserved-words.brs

@@ -11,23 +11,5 @@ sub main()
         print word
     end for
 
-    immediatePromise("foo").then(sub(result)
-        print "promise-like resolved to '" + result + "'"
-    end sub)
-
     print "Hello from line " LINE_NUM
 end sub
-
-' A simple promise-like function that immediately resolves to the provided value.
-' You probably don't want to use it in production.
-' @param {*} val the value this promise-like should immediately resolve to
-' @returns {AssociativeArray} an associative array contianing a `then` property, used to chain
-'                             promise-like constructs.
-function immediatePromise(val as dynamic) as object
-    return {
-        __result: val
-        then: sub(resolved as function)
-            resolved(m.__result)
-        end sub
-    }
-end function