pull reusable logic out of `Bundler`

Reviewed By: jeanlauliac

Differential Revision: D4978045

fbshipit-source-id: 8e2ea14c983d4812e84ab644484380c98eb8da36

packages/metro-bundler/src/Bundler/index.js

@@ -27,6 +27,8 @@ const defaults = require('../../defaults');
 const os = require('os');
 const invariant = require('fbjs/lib/invariant');
 
+const {generateAssetTransformResult, isAssetTypeAnImage} = require('./util');
+
 const {
   sep: pathSeparator,
   join: joinPath,
@@ -95,12 +97,6 @@ const {
   log,
 } = require('../Logger');
 
-const assetPropertyBlacklist = new Set([
-  'files',
-  'fileSystemLocation',
-  'path',
-]);
-
 export type PostProcessModulesOptions = {|
   dev: boolean,
   minify: boolean,
@@ -696,7 +692,7 @@ class Bundler {
       assetUrlPath = assetUrlPath.replace(/\\/g, '/');
     }
 
-    const isImage = Bundler.isAssetTypeAnImage(extname(module.path).slice(1));
+    const isImage = isAssetTypeAnImage(extname(module.path).slice(1));
 
     return this._assetServer.getAssetData(relPath, platform).then(assetData => {
       return Promise.all([isImage ? sizeOf(assetData.files[0]) : null, assetData]);
@@ -719,7 +715,7 @@ class Bundler {
 
       return this._applyAssetPlugins(assetPlugins, asset);
     }).then(asset => {
-      const {code, dependencies, dependencyOffsets} = Bundler.generateAssetTransformResult(asset);
+      const {code, dependencies, dependencyOffsets} = generateAssetTransformResult(asset);
       return {
         asset,
         code,
@@ -728,29 +724,6 @@ class Bundler {
     });
   }
 
-  // Test extension against all types supported by image-size module.
-  // If it's not one of these, we won't treat it as an image.
-  static isAssetTypeAnImage(type: string): boolean {
-    return [
-      'png', 'jpg', 'jpeg', 'bmp', 'gif', 'webp', 'psd', 'svg', 'tiff',
-    ].indexOf(type) !== -1;
-  }
-
-  static generateAssetTransformResult(assetDescriptor: AssetDescriptor): {|
-    code: string,
-    dependencies: Array<string>,
-    dependencyOffsets: Array<number>,
-  |} {
-    const properDescriptor = filterObject(assetDescriptor, assetPropertyBlacklist);
-    const json = JSON.stringify(properDescriptor);
-    const assetRegistryPath = 'react-native/Libraries/Image/AssetRegistry';
-    const code =
-      `module.exports = require(${JSON.stringify(assetRegistryPath)}).registerAsset(${json});`;
-    const dependencies = [assetRegistryPath];
-    const dependencyOffsets = [code.indexOf(assetRegistryPath) - 1];
-    return {code, dependencies, dependencyOffsets};
-  }
-
   _applyAssetPlugins(
     assetPlugins: Array<string>,
     asset: ExtendedAssetDescriptor,
@@ -896,12 +869,4 @@ function getMainModule({dependencies, numPrependedDependencies = 0}) {
   return dependencies[numPrependedDependencies];
 }
 
-function filterObject(object, blacklist) {
-  const copied = Object.assign({}, object);
-  for (const key of blacklist) {
-    delete copied[key];
-  }
-  return copied;
-}
-
 module.exports = Bundler;

packages/metro-bundler/src/Bundler/util.js

@@ -0,0 +1,54 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @flow
+ */
+
+'use strict';
+
+import type {AssetDescriptor} from '.';
+
+const assetPropertyBlacklist = new Set([
+  'files',
+  'fileSystemLocation',
+  'path',
+]);
+
+function generateAssetTransformResult(assetDescriptor: AssetDescriptor): {|
+  code: string,
+  dependencies: Array<string>,
+  dependencyOffsets: Array<number>,
+|} {
+  const properDescriptor = filterObject(assetDescriptor, assetPropertyBlacklist);
+  const json = JSON.stringify(properDescriptor);
+  const assetRegistryPath = 'react-native/Libraries/Image/AssetRegistry';
+  const code =
+    `module.exports = require(${JSON.stringify(assetRegistryPath)}).registerAsset(${json});`;
+  const dependencies = [assetRegistryPath];
+  const dependencyOffsets = [code.indexOf(assetRegistryPath) - 1];
+  return {code, dependencies, dependencyOffsets};
+}
+
+// Test extension against all types supported by image-size module.
+// If it's not one of these, we won't treat it as an image.
+function isAssetTypeAnImage(type: string): boolean {
+  return [
+    'png', 'jpg', 'jpeg', 'bmp', 'gif', 'webp', 'psd', 'svg', 'tiff',
+  ].indexOf(type) !== -1;
+}
+
+function filterObject(object, blacklist) {
+  const copied = Object.assign({}, object);
+  for (const key of blacklist) {
+    delete copied[key];
+  }
+  return copied;
+}
+
+exports.generateAssetTransformResult = generateAssetTransformResult;
+exports.isAssetTypeAnImage = isAssetTypeAnImage;