fetch the module version (#22)

lib/require-module-hook.js

@@ -20,6 +20,7 @@
 const Module = require("module");
 const resolve = require("resolve");
 const path = require("path");
+const fs = require("fs");
 
 module.exports = hook;
 
@@ -38,7 +39,8 @@ function hook(modules, requireCallback) {
         let moduleName = "";
         let matchModuleName = "";
         let enhanceFile = "";
-        let version = "";
+        let version = undefined;
+        let basedir = undefined;
 
         if (enhancedModuleCache.hasOwnProperty(filename)) {
             return enhancedModuleCache[filename];
@@ -56,7 +58,7 @@ function hook(modules, requireCallback) {
             moduleName = isWithScope ?
                 pathSegment[index + 1] + "/" + pathSegment[index + 2] :
                 pathSegment[index + 1];
-            let basedir = pathSegment.slice(0, index + (isWithScope ? 3 : 2)).join(path.sep);
+            basedir = pathSegment.slice(0, index + (isWithScope ? 3 : 2)).join(path.sep);
             try {
                 let res = resolve.sync(moduleName, {basedir: basedir});
                 if (res !== filename) {
@@ -73,6 +75,17 @@ function hook(modules, requireCallback) {
         }
 
         if (modules && modules.indexOf(matchModuleName) === -1) return exports;
+
+        // get version. Because of we enhance Module.prototype.require, so we can't fetch the version by execute
+        // `require(basedir + path.sep + "package.json")` method
+        if (basedir) {
+            const packageJson = path.join(basedir, "package.json");
+            try {
+                version = JSON.parse(fs.readFileSync(packageJson)).version;
+            } catch (e) {
+            }
+        }
+
         if (!enhancedModuleCache.hasOwnProperty(filename)) {
             enhancedModuleCache[filename] = exports;
             enhancedModuleCache[filename] = requireCallback(exports, moduleName, version, enhanceFile);