fix(parse): Include surrounding whitespace in Block nodes(#257)

Updates `Stmt.Block` locations to include surrounding whitespace, and
renamed `startingLocation` to `location`. 

fixes #159

src/parser/Parser.ts

@@ -1198,7 +1198,18 @@ export class Parser {
                 // TODO: Figure out how to handle unterminated blocks well
             }
 
-            return new Stmt.Block(statements, startingToken.location);
+            //the block's location starts at the end of the preceeding token, and stops at the beginning of the `end` token
+            const preceedingToken = tokens[tokens.indexOf(startingToken) - 1];
+            const postceedingToken = tokens[current];
+            const location: Location = {
+                file: startingToken.location.file,
+                start: {
+                    line: preceedingToken.location.end.line,
+                    column: preceedingToken.location.end.column,
+                },
+                end: postceedingToken.location.start,
+            };
+            return new Stmt.Block(statements, location);
         }
 
         function expression(): Expression {

src/parser/Statement.ts

@@ -60,26 +60,11 @@ export class Assignment implements Statement {
 }
 
 export class Block implements Statement {
-    constructor(
-        readonly statements: ReadonlyArray<Statement>,
-        readonly startingLocation: Location
-    ) {}
+    constructor(readonly statements: ReadonlyArray<Statement>, readonly location: Location) {}
 
     accept<R>(visitor: Visitor<R>): BrsType {
         return visitor.visitBlock(this);
     }
-
-    get location() {
-        let end = this.statements.length
-            ? this.statements[this.statements.length - 1].location.end
-            : this.startingLocation.start;
-
-        return {
-            file: this.startingLocation.file,
-            start: this.startingLocation.start,
-            end: end,
-        };
-    }
 }
 
 export class Expression implements Statement {

test/parser/controlFlow/__snapshots__/For.test.js.snap

@@ -4,11 +4,12 @@ exports[`parser for loops accepts a 'step' clause 1`] = `
 Array [
   For {
     "body": Block {
-      "startingLocation": Object {
+      "location": Object {
         "end": Object {
           "column": -9,
           "line": -9,
         },
+        "file": undefined,
         "start": Object {
           "column": -9,
           "line": -9,
@@ -174,11 +175,12 @@ exports[`parser for loops allows 'next' to terminate loop 1`] = `
 Array [
   For {
     "body": Block {
-      "startingLocation": Object {
+      "location": Object {
         "end": Object {
           "column": -9,
           "line": -9,
         },
+        "file": undefined,
         "start": Object {
           "column": -9,
           "line": -9,
@@ -329,11 +331,12 @@ exports[`parser for loops defaults a missing 'step' clause to '1' 1`] = `
 Array [
   For {
     "body": Block {
-      "startingLocation": Object {
+      "location": Object {
         "end": Object {
           "column": -9,
           "line": -9,
         },
+        "file": undefined,
         "start": Object {
           "column": -9,
           "line": -9,

test/parser/controlFlow/__snapshots__/ForEach.test.js.snap

@@ -4,11 +4,12 @@ exports[`parser foreach loops allows 'next' to terminate loop 1`] = `
 Array [
   ForEach {
     "body": Block {
-      "startingLocation": Object {
+      "location": Object {
         "end": Object {
           "column": -9,
           "line": -9,
         },
+        "file": undefined,
         "start": Object {
           "column": -9,
           "line": -9,
@@ -108,11 +109,12 @@ exports[`parser foreach loops requires a name and target 1`] = `
 Array [
   ForEach {
     "body": Block {
-      "startingLocation": Object {
+      "location": Object {
         "end": Object {
           "column": -9,
           "line": -9,
         },
+        "file": undefined,
         "start": Object {
           "column": -9,
           "line": -9,