Define version only in one place

package.json

@@ -32,7 +32,8 @@
         "rollup-plugin-babel": "4.0.3",
         "rollup-plugin-commonjs": "9.1.6",
         "rollup-plugin-multi-entry": "2.0.2",
-        "rollup-plugin-node-resolve": "3.4.0"
+        "rollup-plugin-node-resolve": "3.4.0",
+        "rollup-plugin-json": "3.1.0"
     },
     "devDependencies": {
         "coveralls": "3.0.2",

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

@@ -3,6 +3,7 @@
 "use strict";
 
 const util = require( "../../util" );
+const VERSION = require( "../../../package.json" ).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 v${ VERSION }, https://pegjs.org/`;
             const header = options.header;
 
             if ( typeof header === "string" ) {

packages/pegjs/lib/peg.js

@@ -8,7 +8,7 @@ const util = require( "./util" );
 
 const peg = {
     // PEG.js version (uses semantic versioning).
-    VERSION: "0.11.0-dev",
+    VERSION: require( "../package.json" ).version,
 
     GrammarError: GrammarError,
     ast: ast,

rollup.config.js

@@ -3,6 +3,7 @@
 const dedent = require( "dedent" );
 const babel = require( "rollup-plugin-babel" );
 const commonjs = require( "rollup-plugin-commonjs" );
+const json = require( "rollup-plugin-json" );
 const resolve = require( "rollup-plugin-node-resolve" );
 const { terser } = require( "rollup-plugin-terser" );
 
@@ -44,6 +45,7 @@ function generate( target ) {
         plugins: [
             commonjs(),
             babel( babelOptions ),
+            json( { namedExports: false } ),
             resolve(),
         ],
     };

server.js

@@ -9,6 +9,7 @@ const ms = require( "pretty-ms" );
 const rollup = require( "rollup" );
 const babel = require( "rollup-plugin-babel" );
 const commonjs = require( "rollup-plugin-commonjs" );
+const json = require( "rollup-plugin-json" );
 const multiEntry = require( "rollup-plugin-multi-entry" );
 const resolve = require( "rollup-plugin-node-resolve" );
 
@@ -121,6 +122,7 @@ babelOptions.runtimeHelpers = true;
         plugins: [
             multiEntry(),
             commonjs(),
+            json( { namedExports: false } ),
             babel( babelOptions ),
             resolve(),
         ],

yarn.lock

@@ -4292,6 +4292,12 @@ rollup-plugin-commonjs@9.1.6:
     resolve "^1.5.0"
     rollup-pluginutils "^2.0.1"
 
+rollup-plugin-json@3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/rollup-plugin-json/-/rollup-plugin-json-3.1.0.tgz#7c1daf60c46bc21021ea016bd00863561a03321b"
+  dependencies:
+    rollup-pluginutils "^2.3.1"
+
 rollup-plugin-multi-entry@2.0.2:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/rollup-plugin-multi-entry/-/rollup-plugin-multi-entry-2.0.2.tgz#ab50fbabec62526706492badadd8d59f139e4d58"
@@ -4314,7 +4320,7 @@ rollup-plugin-terser@2.0.2:
     jest-worker "^23.2.0"
     terser "^3.8.2"
 
-rollup-pluginutils@^2.0.1, rollup-pluginutils@^2.3.0:
+rollup-pluginutils@^2.0.1, rollup-pluginutils@^2.3.0, rollup-pluginutils@^2.3.1:
   version "2.3.1"
   resolved "https://registry.yarnpkg.com/rollup-pluginutils/-/rollup-pluginutils-2.3.1.tgz#760d185ccc237dedc12d7ae48c6bcd127b4892d0"
   dependencies: