Ensure VERSION is consistent

The PEG.js version is exported and also written into the generated parser. In both these instances the version is a separate string, which means every time the version is bumped, it has to be changed in 3 places. This commit makes it slightly less of a maintenance burden.

packages/pegjs/lib/compiler/passes/generate-js.js

@@ -3,6 +3,7 @@
 "use strict";
 
 const util = require( "../../util" );
+const VERSION = require( "../../version" );
 
 // Generates parser JavaScript code.
 function generateJS( ast, session, options ) {
@@ -1593,7 +1594,7 @@ function generateJS( ast, session, options ) {
 
         function generateHeaderComment() {
 
-            let comment = "// Generated by PEG.js v0.11.0-dev, https://pegjs.org/";
+            let comment = `// Generated by PEG.js ${ VERSION }, https://pegjs.org/`;
             const header = options.header;
 
             if ( typeof header === "string" ) {

packages/pegjs/lib/parser.js

@@ -1,4 +1,4 @@
-// Generated by PEG.js v0.11.0-dev, https://pegjs.org/
+// Generated by PEG.js 0.11.0-dev, https://pegjs.org/
 
 /* eslint-disable */
 

packages/pegjs/lib/peg.js

@@ -5,10 +5,11 @@ const ast = require( "./ast" );
 const compiler = require( "./compiler" );
 const parser = require( "./parser" );
 const util = require( "./util" );
+const VERSION = require( "./version" );
 
 const peg = {
     // PEG.js version (uses semantic versioning).
-    VERSION: "0.11.0-dev",
+    VERSION: VERSION,
 
     GrammarError: GrammarError,
     ast: ast,

packages/pegjs/lib/version.js

@@ -0,0 +1,8 @@
+"use strict";
+
+/**
+ * PEG.js version (uses semantic versioning).
+ */
+const VERSION = "0.11.0-dev";
+
+module.exports = VERSION;

packages/pegjs/typings/modules.d.ts

@@ -6,6 +6,12 @@ declare module "pegjs" {
 
 }
 
+declare module "pegjs/lib/version" {
+
+    export default peg.VERSION;
+
+}
+
 declare module "pegjs/lib/grammar-error" {
 
     export default peg.GrammarError;