Changed adding invalid as arg to empty callfunc invocations by default (

#1043)

* Changed adding invalid as arg to empty callfunc invocations by default

* Update src/BsConfig.ts

Co-authored-by: Bronley Plumb <bronley@gmail.com>

* Update bsconfig.schema.json

Co-authored-by: Bronley Plumb <bronley@gmail.com>

---------

Co-authored-by: Bronley Plumb <bronley@gmail.com>

bsconfig.schema.json

@@ -281,6 +281,11 @@
             "description": "Allow brighterscript features (classes, interfaces, etc...) to be included in BrightScript (`.brs`) files, and force those files to be transpiled.",
             "type": "boolean",
             "default": false
+        },
+        "legacyCallfuncHandling": {
+            "description": "Legacy RokuOS versions required at least one argument in callfunc() invocations. Previous brighterscript versions handled this by inserting invalid as an argument when no other args are present. This is not necessary in modern RokuOS versions.",
+            "type": "boolean",
+            "default": false
         }
     }
 }

src/BsConfig.ts

@@ -195,6 +195,12 @@ export interface BsConfig {
      * scripts inside `source` that depend on bslib.brs.  Defaults to `source`.
      */
     bslibDestinationDir?: string;
+
+    /* Legacy RokuOS versions required at least one argument in callfunc() invocations.
+     * Previous brighterscript versions handled this by inserting invalid as an argument when no other args are present.
+     * This is not necessary in modern RokuOS versions.
+     */
+    legacyCallfuncHandling?: boolean;
 }
 
 type OptionalBsConfigFields =

src/files/BrsFile.spec.ts

@@ -2613,7 +2613,8 @@ describe('BrsFile', () => {
                 expectZeroDiagnostics(program);
             });
 
-            it('sets invalid on empty callfunc', async () => {
+            it('sets invalid on empty callfunc with legacyCallfuncHandling=true', async () => {
+                program.options.legacyCallfuncHandling = true;
                 await testTranspile(`
                     sub main()
                         node = invalid
@@ -2631,6 +2632,24 @@ describe('BrsFile', () => {
                 `);
             });
 
+            it('empty callfunc allowed by default', async () => {
+                await testTranspile(`
+                    sub main()
+                        node = invalid
+                        node@.doSomething()
+                        m.top.node@.doSomething()
+                        m.top.node@.doSomething(1)
+                    end sub
+                `, `
+                    sub main()
+                        node = invalid
+                        node.callfunc("doSomething")
+                        m.top.node.callfunc("doSomething")
+                        m.top.node.callfunc("doSomething", 1)
+                    end sub
+                `);
+            });
+
             it('includes original arguments', async () => {
                 await testTranspile(`
                     sub main()

src/parser/Expression.ts

@@ -1140,14 +1140,11 @@ export class CallfuncExpression extends Expression {
             state.sourceNode(this.operator, '.callfunc'),
             state.transpileToken(this.openingParen),
             //the name of the function
-            state.sourceNode(this.methodName, ['"', this.methodName.text, '"']),
-            ', '
+            state.sourceNode(this.methodName, ['"', this.methodName.text, '"'])
         );
-        //transpile args
-        //callfunc with zero args never gets called, so pass invalid as the first parameter if there are no args
-        if (this.args.length === 0) {
-            result.push('invalid');
-        } else {
+        if (this.args?.length > 0) {
+            result.push(', ');
+            //transpile args
             for (let i = 0; i < this.args.length; i++) {
                 //add comma between args
                 if (i > 0) {
@@ -1156,7 +1153,10 @@ export class CallfuncExpression extends Expression {
                 let arg = this.args[i];
                 result.push(...arg.transpile(state));
             }
+        } else if (state.options.legacyCallfuncHandling) {
+            result.push(', ', 'invalid');
         }
+
         result.push(
             state.transpileToken(this.closingParen)
         );

src/util.ts

@@ -375,7 +375,8 @@ export class Util {
             emitDefinitions: config.emitDefinitions === true ? true : false,
             removeParameterTypes: config.removeParameterTypes === true ? true : false,
             logLevel: logLevel,
-            bslibDestinationDir: bslibDestinationDir
+            bslibDestinationDir: bslibDestinationDir,
+            legacyCallfuncHandling: config.legacyCallfuncHandling === true ? true : false
         };
 
         //mutate `config` in case anyone is holding a reference to the incomplete one