fix bug in getDependencies

Author: Baitu Huang

README.md

@@ -15,7 +15,9 @@ npm install vue-flags-webpack-plugin -D
 options:
 * `flags` ({[k: string]: boolean} | string, required)
 
-  a plain object that contains flags value(boolean) or a file path that exports the final flags object.
+  A plain object that contains flags value(boolean).
+
+  Or a file path(will be executed many times!) which exports the final flags object.
   ```javascript
   flags: {
     FLAG_A: true,
@@ -38,7 +40,7 @@ options:
   `watch` could also be an array including extra files paths which will be watched.
   ```javascript
   watch: process.env.NODE_ENV === 'development'
-  // or
+  // or (no need to add extra files in most cases, just set it true)
   watch: [ './config/flag1.js', './config/flag2.js' ]
   ```
 

lib/resolve-options.js

@@ -5,7 +5,7 @@ const clearModule = require('clear-module')
 const validateOptions = require('schema-utils')
 
 const { RESOLVED_FLAGS_PATH, PLUGIN_NAME } = require('./constants')
-const { genError, toFunc } = require('./utils')
+const { genError, toFunc, getDependencies } = require('./utils')
 
 const flagsSchema = {
   type: 'object',
@@ -98,9 +98,9 @@ function updateGetFlags (flagsPaths, errors = 0) {
   let newFlags
   try {
     newFlags = require(flagPath)
-  } catch (e) {
+  } catch (err) {
     // errors is used for different editor file-writting mechanism
-    if (errors > 10) { throw e }
+    if (errors > 10) { throw err } // 😔
     return updateGetFlags(flagsPaths, errors + 1)
   }
   validateOptions(flagsSchema, newFlags, PLUGIN_NAME)
@@ -138,8 +138,9 @@ function setOptions ({ flags, ignoreFiles, namespace, watch }, context, watchOpt
     if (!dev) {
       throw genError('Make sure only use "watch" in development mode!')
     }
-    pluginOptions.flags = updateGetFlags(flags)
-    const flagFiles = [flags]
+    const flagFiles = getDependencies(() => {
+      pluginOptions.flags = updateGetFlags(flags)
+    }, [flags])
     if (Array.isArray(watch)) {
       watch.forEach(file => {
         if (!path.isAbsolute(file)) {

lib/utils.js

@@ -34,3 +34,31 @@ exports.toFunc = function toFunc (exp, useWith = true) {
   }
   return funcsMap[exp]
 }
+
+const Module = require('module')
+const path = require('path')
+const clearModule = require('clear-module')
+exports.getDependencies = function getDependencies (callback, deps) {
+  deps = new Set(deps)
+  const resolveFilename = Module._resolveFilename
+  Module._resolveFilename = function _resolveFilename (req, ...args) {
+    const filename = resolveFilename.call(this, req, ...args)
+    if (path.isAbsolute(req) && !/node_modules/.test(req)) {
+      deps.add(filename)
+    }
+    if (/^\.{1,2}\//.test(req)) {
+      deps.add(filename)
+    }
+    return filename
+  }
+  let size
+  do { // against node cache
+    size = deps.size
+    for (let dep of deps) {
+      clearModule(dep)
+    }
+    callback()
+  } while (size !== deps.size)
+  Module._resolveFilename = resolveFilename
+  return [...deps]
+}