Empty print statement

package.json

@@ -14,8 +14,8 @@
     "clean": "rimraf ./lib ./types",
     "test": "jest",
     "lint": "tslint --project .",
-    "prettier:write": "prettier --write '{bin,src,test}/**/*.{js,ts}'",
-    "prettier": "prettier --check '{bin,src,test}/**/*.{js,ts}'",
+    "prettier:write": "prettier --write \"{bin,src,test}/**/*.{js,ts}\"",
+    "prettier": "prettier --check \"{bin,src,test}/**/*.{js,ts}\"",
     "prepublishOnly": "npm-run-all --serial clean build lint prettier test"
   },
   "files": [

src/parser/Parser.ts

@@ -800,7 +800,7 @@ export class Parser {
 
                 //keep track of the current error count, because if the then branch fails,
                 //we will trash them in favor of a single error on if
-                var errorsLengthBeforeBlock = errors.length;
+                let errorsLengthBeforeBlock = errors.length;
 
                 // we're parsing a multi-line ("block") form of the BrightScript if/then/else and must find
                 // a trailing "end if"
@@ -1056,7 +1056,14 @@ export class Parser {
                 | Expr.Expression
                 | Stmt.PrintSeparator.Tab
                 | Stmt.PrintSeparator.Space)[] = [];
-            values.push(expression());
+
+            //print statements can be empty, so look for empty print conditions
+            if (isAtEnd() || check(Lexeme.Newline, Lexeme.Colon)) {
+                let emptyStringLiteral = new Expr.Literal(new BrsString(""), printKeyword.location);
+                values.push(emptyStringLiteral);
+            } else {
+                values.push(expression());
+            }
 
             while (!check(Lexeme.Newline, Lexeme.Colon, ...additionalterminators) && !isAtEnd()) {
                 if (check(Lexeme.Semicolon)) {

test/parser/statement/PrintStatement.test.js

@@ -24,6 +24,14 @@ describe("parser print statements", () => {
         expect(statements).toMatchSnapshot();
     });
 
+    it("supports empty print", () => {
+        let { statements, errors } = brs.parser.Parser.parse([token(Lexeme.Print), EOF]);
+        expect(errors).toEqual([]);
+        expect(statements).toBeDefined();
+        expect(statements).not.toBeNull();
+        expect(statements).toMatchSnapshot();
+    });
+
     it("parses print lists with no separator", () => {
         let { statements, errors } = parser.parse([
             token(Lexeme.Print),

test/parser/statement/__snapshots__/PrintStatement.test.js.snap

@@ -221,3 +221,46 @@ Array [
   },
 ]
 `;
+
+exports[`parser print statements supports empty print 1`] = `
+Array [
+  Print {
+    "expressions": Array [
+      Literal {
+        "_location": Object {
+          "end": Object {
+            "column": -9,
+            "line": -9,
+          },
+          "start": Object {
+            "column": -9,
+            "line": -9,
+          },
+        },
+        "value": BrsString {
+          "kind": 2,
+          "value": "",
+        },
+      },
+    ],
+    "tokens": Object {
+      "print": Object {
+        "isReserved": false,
+        "kind": "Print",
+        "literal": undefined,
+        "location": Object {
+          "end": Object {
+            "column": -9,
+            "line": -9,
+          },
+          "start": Object {
+            "column": -9,
+            "line": -9,
+          },
+        },
+        "text": undefined,
+      },
+    },
+  },
+]
+`;