feat: Pass optional stats config to getStats().toJson()

Fixes #18

Author: evocateur

README.md

@@ -4,7 +4,7 @@ Webpack Stats Plugin
 [![Build Status][trav_img]][trav_site]
 
 This plugin will ingest the webpack
-[stats](https://github.com/webpack/docs/wiki/node.js-api#stats) object,
+[stats](https://webpack.js.org/configuration/stats/#stats) object,
 process / transform the object and write out to a file for further consumption.
 
 The most common use case is building a hashed bundle and wanting to
@@ -41,6 +41,25 @@ module.exports = {
 }
 ```
 
+### Custom `stats` Configuration
+
+This option is passed to the webpack compiler's [`getStats().toJson()`][https://webpack.js.org/api/node/#stats-tojson-options-] method.
+
+```js
+const { StatsWriterPlugin } = require("webpack-stats-plugin")
+
+module.exports = {
+  plugins: [
+    new StatsWriterPlugin({
+      stats: {
+        all: false,
+        assets: true
+      }
+    })
+  ]
+}
+```
+
 ### Custom Transform Function
 
 The transform function has a signature of:
@@ -103,13 +122,14 @@ module.exports = {
 
 ### `StatsWriterPlugin(opts)`
 * **opts** (`Object`) options
-* **opts.filename** (`String`) output file name (Default: "stat.json")
+* **opts.filename** (`String`) output file name (Default: "stats.json")
 * **opts.fields** (`Array`) fields of stats obj to keep (Default: \["assetsByChunkName"\])
+* **opts.stats** (`Object|String`) stats config object or string preset (Default: `{}`)
 * **opts.transform** (`Function|Promise`) transform stats obj (Default: `JSON.stringify()`)
 
 Stats writer module.
 
-Stats can be a string or array (we"ll have array from using source maps):
+Stats can be a string or array (we'll have an array due to source maps):
 
 ```js
 "assetsByChunkName": {
@@ -126,9 +146,13 @@ only include those. However, if you want the _whole thing_ (maybe doing an
 `opts.transform` function), then you can set `fields: null` in options to
 get **all** of the stats object.
 
+You may also pass a custom stats config object (or string preset) via `opts.stats`
+in order to select exactly what you want added to the data passed to the transform.
+When `opts.stats` is passed, `opts.fields` will default to `null`.
+
 See:
-- http://webpack.github.io/docs/long-term-caching.html#get-filenames-from-stats
-- https://github.com/webpack/docs/wiki/node.js-api#stats
+- https://webpack.js.org/configuration/stats/#stats
+- https://webpack.js.org/api/node/#stats-object
 
 **`filename`**: The `opts.filename` option can be a file name or path relative to
 `output.path` in webpack configuration. It should not be absolute.

lib/stats-writer-plugin.js

@@ -6,7 +6,7 @@ const DEFAULT_TRANSFORM = (data) => JSON.stringify(data, null, INDENT);
 /**
  * Stats writer module.
  *
- * Stats can be a string or array (we"ll have array from using source maps):
+ * Stats can be a string or array (we'll have array due to source maps):
  *
  * ```js
  * "assetsByChunkName": {
@@ -23,9 +23,13 @@ const DEFAULT_TRANSFORM = (data) => JSON.stringify(data, null, INDENT);
  * `opts.transform` function), then you can set `fields: null` in options to
  * get **all** of the stats object.
  *
+ * You may also pass a custom stats config object (or string preset) via `opts.stats`
+ * in order to select exactly what you want added to the data passed to the transform.
+ * When `opts.stats` is passed, `opts.fields` will default to `null`.
+ *
  * See:
- * - http://webpack.github.io/docs/long-term-caching.html#get-filenames-from-stats
- * - https://github.com/webpack/docs/wiki/node.js-api#stats
+ * - https://webpack.js.org/configuration/stats/#stats
+ * - https://webpack.js.org/api/node/#stats-object
  *
  * **`filename`**: The `opts.filename` option can be a file name or path relative to
  * `output.path` in webpack configuration. It should not be absolute.
@@ -42,8 +46,9 @@ const DEFAULT_TRANSFORM = (data) => JSON.stringify(data, null, INDENT);
  *   any problems.
  *
  * @param {Object}   opts           options
- * @param {String}   opts.filename  output file name (Default: "stat.json")
+ * @param {String}   opts.filename  output file name (Default: "stats.json")
  * @param {Array}    opts.fields    fields of stats obj to keep (Default: \["assetsByChunkName"\])
+ * @param {Object|String}    opts.stats     stats config object or string preset (Default: `{}`)
  * @param {Function|Promise} opts.transform transform stats obj (Default: `JSON.stringify()`)
  *
  * @api public
@@ -54,7 +59,13 @@ class StatsWriterPlugin {
     this.opts = {};
     this.opts.filename = opts.filename || "stats.json";
     this.opts.fields = typeof opts.fields !== "undefined" ? opts.fields : ["assetsByChunkName"];
+    this.opts.stats = opts.stats || {};
     this.opts.transform = opts.transform || DEFAULT_TRANSFORM;
+
+    if (typeof opts.stats !== "undefined" && typeof opts.fields === "undefined") {
+      // if custom stats config provided, do not filter fields unless explicitly configured
+      this.opts.fields = null;
+    }
   }
 
   apply(compiler) {
@@ -67,9 +78,9 @@ class StatsWriterPlugin {
 
   emitStats(curCompiler, callback) {
     // Get stats.
-    // **Note**: In future, could pass something like `{ showAssets: true }`
-    // to the `getStats()` function for more limited object returned.
-    let stats = curCompiler.getStats().toJson();
+    // The second argument automatically skips heavy options (reasons, source, etc)
+    // if they are otherwise unspecified.
+    let stats = curCompiler.getStats().toJson(this.opts.stats, "forToString");
 
     // Filter to fields.
     if (this.opts.fields) {

test/expected/build/stats-custom-stats-fields.json

@@ -0,0 +1,5 @@
+{
+  "errors": [],
+  "warnings": [],
+  "assets": []
+}

test/expected/build/stats-custom-stats.json

@@ -0,0 +1,8 @@
+{
+  "errors": [],
+  "warnings": [],
+  "assetsByChunkName": {
+    "main": "0fbcc60c464127ab3381.main.js"
+  },
+  "assets": []
+}

test/expected/build/stats-override-tostring-opt.json

@@ -0,0 +1,16 @@
+{
+  "errors": [],
+  "warnings": [],
+  "chunks": [
+    {
+      "rendered": true,
+      "initial": true,
+      "entry": true,
+      "size": 102,
+      "names": [
+        "main"
+      ],
+      "parents": []
+    }
+  ]
+}

test/webpack4/webpack.config.js

@@ -6,6 +6,24 @@
 const path = require("path");
 const StatsWriterPlugin = require("../../index").StatsWriterPlugin;
 const INDENT = 2;
+const STAT_RESET = Object.freeze({
+  // fallback for new stuff added after v3
+  all: false,
+  // explicitly turn off older fields
+  // (webpack <= v2.7.0 does not support "all")
+  performance: false,
+  hash: false,
+  version: false,
+  timings: false,
+  entrypoints: false,
+  chunks: false,
+  chunkModules: false,
+  cached: false,
+  cachedAssets: false,
+  children: false,
+  moduleTrace: false,
+  assets: false
+});
 
 module.exports = {
   mode: "development",
@@ -33,7 +51,7 @@ module.exports = {
       transform(data) {
         const assetsByChunkName = data.assetsByChunkName;
         return Object.keys(assetsByChunkName).reduce((memo, key) => {
-          return `${memo}${key } | ${ assetsByChunkName[key] }\n`;
+          return `${memo}${key} | ${assetsByChunkName[key]}\n`;
         }, "Name | Asset\n:--- | :----\n");
       }
     }),
@@ -65,6 +83,49 @@ module.exports = {
             main: data.assetsByChunkName.main
           }, null, INDENT));
       }
+    }),
+    // Custom stats
+    new StatsWriterPlugin({
+      filename: "stats-custom-stats.json",
+      stats: Object.assign({}, STAT_RESET, {
+        assets: true
+      }),
+      transform(data) {
+        // webpack >= v3 adds this field unconditionally, so remove it
+        delete data.filteredAssets;
+        return JSON.stringify(data, null, INDENT);
+      }
+    }),
+    new StatsWriterPlugin({
+      filename: "stats-custom-stats-fields.json",
+      fields: ["errors", "warnings", "assets"],
+      stats: Object.assign({}, STAT_RESET, {
+        assets: true
+      })
+    }),
+    new StatsWriterPlugin({
+      filename: "stats-override-tostring-opt.json",
+      stats: Object.assign({}, STAT_RESET, {
+        // chunks are normally omitted due to second argument of .toJson()
+        chunks: true
+      }),
+      transform(data) {
+        // normalize subset of chunk metadata across all versions of webpack
+        data.chunks = data.chunks.map((chunk) => {
+          return [
+            "rendered",
+            "initial",
+            "entry",
+            "size",
+            "names",
+            "parents"
+          ].reduce((obj, key) => {
+            obj[key] = chunk[key];
+            return obj;
+          }, {});
+        });
+        return JSON.stringify(data, null, INDENT);
+      }
     })
   ]
 };