This function was working inline, reflect this clearly

Summary:
This function was working on a source map object inline and then returning the same reference.

For clarity it's better if it either clones the whole thing (that would be a waste) or not return the reference at all. Also renamed the function (but not the file) for clarity.

Dropped the unused check and updated callsites instead.

Reviewed By: mjesun

Differential Revision: D6884241

fbshipit-source-id: 33aa7a1ad7096510903bbb74dd6b9c675b81aff5

packages/metro/src/lib/relativizeSourceMap.js

@@ -16,13 +16,13 @@ const path = require('path');
 
 import type {MetroSourceMap} from 'metro-source-map';
 
-function relativizeSourceMapInternal(
+function relativizeSourceMapInline(
   sourceMap: MetroSourceMap,
   sourcesRoot: string,
 ) {
   if (sourceMap.mappings === undefined) {
     for (let i = 0; i < sourceMap.sections.length; i++) {
-      relativizeSourceMapInternal(sourceMap.sections[i].map, sourcesRoot);
+      relativizeSourceMapInline(sourceMap.sections[i].map, sourcesRoot);
     }
   } else {
     for (let i = 0; i < sourceMap.sources.length; i++) {
@@ -31,15 +31,4 @@ function relativizeSourceMapInternal(
   }
 }
 
-function relativizeSourceMap(
-  sourceMap: MetroSourceMap,
-  sourcesRoot?: string,
-): MetroSourceMap {
-  if (!sourcesRoot) {
-    return sourceMap;
-  }
-  relativizeSourceMapInternal(sourceMap, sourcesRoot);
-  return sourceMap;
-}
-
-module.exports = relativizeSourceMap;
+module.exports = relativizeSourceMapInline;

packages/metro/src/shared/output/bundle.js

@@ -15,7 +15,7 @@
 const Server = require('../../Server');
 
 const meta = require('./meta');
-const relativizeSourceMap = require('../../lib/relativizeSourceMap');
+const relativizeSourceMapInline = require('../../lib/relativizeSourceMap');
 const writeFile = require('./writeFile');
 
 import type {OutputOptions, RequestOptions} from '../types.flow';
@@ -33,11 +33,12 @@ function buildBundle(
   });
 }
 
-function createCodeWithMap(map: string, sourceMapSourcesRoot: string): string {
-  const sourceMap = relativizeSourceMap(
-    (JSON.parse(map): MetroSourceMap),
-    sourceMapSourcesRoot,
-  );
+function relativateSerializedMap(
+  map: string,
+  sourceMapSourcesRoot: string,
+): string {
+  const sourceMap = (JSON.parse(map): MetroSourceMap);
+  relativizeSourceMapInline(sourceMap, sourceMapSourcesRoot);
   return JSON.stringify(sourceMap);
 }
 
@@ -70,7 +71,7 @@ function saveBundleAndMap(
     let {map} = bundle;
     if (sourcemapSourcesRoot !== undefined) {
       log('start relativating source map');
-      map = createCodeWithMap(map, sourcemapSourcesRoot);
+      map = relativateSerializedMap(map, sourcemapSourcesRoot);
       log('finished relativating');
     }
 

packages/metro/src/shared/output/unbundle/as-assets.js

@@ -16,7 +16,7 @@ const MAGIC_UNBUNDLE_NUMBER = require('./magic-number');
 const buildSourceMapWithMetaData = require('./build-unbundle-sourcemap-with-metadata');
 const mkdirp = require('mkdirp');
 const path = require('path');
-const relativizeSourceMap = require('../../../lib/relativizeSourceMap');
+const relativizeSourceMapInline = require('../../../lib/relativizeSourceMap');
 const writeFile = require('../writeFile');
 const writeSourceMap = require('./write-sourcemap');
 
@@ -66,15 +66,15 @@ function saveAsAssets(
   );
   writeUnbundle.then(() => log('Done writing unbundle output'));
 
-  const sourceMap = relativizeSourceMap(
-    buildSourceMapWithMetaData({
-      fixWrapperOffset: true,
-      lazyModules: lazyModules.concat(),
-      moduleGroups: null,
-      startupModules: startupModules.concat(),
-    }),
-    sourcemapSourcesRoot,
-  );
+  const sourceMap = buildSourceMapWithMetaData({
+    fixWrapperOffset: true,
+    lazyModules: lazyModules.concat(),
+    moduleGroups: null,
+    startupModules: startupModules.concat(),
+  });
+  if (sourcemapSourcesRoot !== undefined) {
+    relativizeSourceMapInline(sourceMap, sourcemapSourcesRoot);
+  }
 
   return Promise.all([
     writeUnbundle,

packages/metro/src/shared/output/unbundle/as-indexed-file.js

@@ -15,7 +15,7 @@ const MAGIC_UNBUNDLE_FILE_HEADER = require('./magic-number');
 
 const buildSourceMapWithMetaData = require('./build-unbundle-sourcemap-with-metadata');
 const fs = require('fs');
-const relativizeSourceMap = require('../../../lib/relativizeSourceMap');
+const relativizeSourceMapInline = require('../../../lib/relativizeSourceMap');
 const writeSourceMap = require('./write-sourcemap');
 
 const {joinModules} = require('./util');
@@ -62,15 +62,15 @@ function saveAsIndexedFile(
   ).then(() => log('Done writing unbundle output'));
 
   if (sourcemapOutput) {
-    const sourceMap = relativizeSourceMap(
-      buildSourceMapWithMetaData({
-        startupModules: startupModules.concat(),
-        lazyModules: lazyModules.concat(),
-        moduleGroups,
-        fixWrapperOffset: true,
-      }),
-      sourcemapSourcesRoot,
-    );
+    const sourceMap = buildSourceMapWithMetaData({
+      startupModules: startupModules.concat(),
+      lazyModules: lazyModules.concat(),
+      moduleGroups,
+      fixWrapperOffset: true,
+    });
+    if (sourcemapSourcesRoot !== undefined) {
+      relativizeSourceMapInline(sourceMap, sourcemapSourcesRoot);
+    }
 
     const wroteSourceMap = writeSourceMap(
       sourcemapOutput,