refactor(@angular-devkit/build-angular): remove esVersionInFileName build option

This option can be determined via `wco.differentialLoadingMode`

Author: alan-agius4

packages/angular_devkit/build_angular/src/utils/build-options.ts

@@ -76,8 +76,6 @@ export interface BuildOptions {
   /** @deprecated use only for compatibility in 8.x; will be removed in 9.0 */
   rebaseRootRelativeCssUrls?: boolean;
 
-  /* Append script target version to filename. */
-  esVersionInFileName?: boolean;
   experimentalRollupPass?: boolean;
   allowedCommonJsDependencies?: string[];
 }

packages/angular_devkit/build_angular/src/webpack/configs/common.ts

@@ -70,7 +70,7 @@ export function getCommonConfig(wco: WebpackConfigOptions): Configuration {
 
   const targetInFileName = getEsVersionForFileName(
     tsConfig.options.target,
-    buildOptions.esVersionInFileName,
+    wco.differentialLoadingMode,
   );
 
   if (buildOptions.main) {
@@ -126,7 +126,6 @@ export function getCommonConfig(wco: WebpackConfigOptions): Configuration {
     if (differentialLoadingMode || tsConfig.options.target === ScriptTarget.ES5) {
       const buildBrowserFeatures = new BuildBrowserFeatures(
         projectRoot,
-        tsConfig.options.target || ScriptTarget.ES5,
       );
 
       if (buildBrowserFeatures.isEs5SupportNeeded()) {

packages/angular_devkit/build_angular/src/webpack/utils/helpers.ts

@@ -101,20 +101,20 @@ export function getSourceMapDevTool(
  * Returns an ES version file suffix to differentiate between various builds.
  */
 export function getEsVersionForFileName(
-  scriptTargetOverride: ScriptTarget | undefined,
+  scriptTarget: ScriptTarget | undefined,
   esVersionInFileName = false,
 ): string {
-  if (!esVersionInFileName || scriptTargetOverride === undefined) {
+  if (!esVersionInFileName || scriptTarget === undefined) {
     return '';
   }
 
-  if (scriptTargetOverride === ScriptTarget.ESNext) {
+  if (scriptTarget === ScriptTarget.ESNext) {
     return '-esnext';
   }
 
-  return '-' + ScriptTarget[scriptTargetOverride].toLowerCase();
+  return '-' + ScriptTarget[scriptTarget].toLowerCase();
 }
 
-export function isPolyfillsEntry(name: string) {
+export function isPolyfillsEntry(name: string): boolean {
   return name === 'polyfills' || name === 'polyfills-es5';
 }