fix(@angular-devkit/build-optimizer): don't wrap enum like nodes which are inside of methods.

With this change we stop recursive lookup when the current node is not a BlockLike.

This change should also, improve the BO overall speed as it's reduces a lot of recursive lookups.

Fixes #15145

Author: alan-agius4

packages/angular_devkit/build_optimizer/src/transforms/wrap-enums.ts

@@ -56,7 +56,7 @@ function visitBlockStatements(
           return node;
       }
     } else {
-      return ts.visitEachChild(node, visitor, context);
+      return node;
     }
   };
 
@@ -112,7 +112,7 @@ function visitBlockStatements(
             oIndex++;
           }
 
-          const enumStatements = findStatements(name, statements, oIndex + 1);
+          const enumStatements = findStatements(name, statements, oIndex, 1);
           if (!enumStatements) {
             continue;
           }
@@ -316,6 +316,7 @@ function findStatements(
   name: string,
   statements: ts.NodeArray<ts.Statement>,
   statementIndex: number,
+  offset = 0,
 ): ts.Statement[] | undefined {
   let count = 1;
 
@@ -369,7 +370,7 @@ function findStatements(
   }
 
   if (count > 1) {
-    return statements.slice(statementIndex, statementIndex + count);
+    return statements.slice(statementIndex + offset, statementIndex + count);
   }
 
   return undefined;

packages/angular_devkit/build_optimizer/src/transforms/wrap-enums_spec.ts

@@ -88,6 +88,37 @@ describe('wrap enums and classes transformer', () => {
       expect(tags.oneLine`${transform(input)}`).toEqual(tags.oneLine`${output}`);
     });
 
+    it('should not wrap enum like which are inside of methods', () => {
+      const input = tags.stripIndent`
+        class LayoutDirective {
+          constructor(elRef) { }
+
+          applyStyleToElement(element, style, value) {
+            let styles = {};
+            if (typeof style === 'string') {
+                styles[style] = value;
+                style = styles;
+            }
+            styles = this.layoutConfig.disableVendorPrefixes ? style : applyCssPrefixes(style);
+            this._applyMultiValueStyleToElement(styles, element);
+          }
+        }
+        LayoutDirective.ctorParameters = () => [
+          { type: ElementRef }
+        ];
+      `;
+
+      const output = tags.stripIndent`
+        let LayoutDirective = /*@__PURE__*/ (() => {
+          ${input}
+
+          return LayoutDirective;
+        })();
+      `;
+
+      expect(tags.oneLine`${transform(input)}`).toEqual(tags.oneLine`${output}`);
+    });
+
     it('should ClassDeclarations that are referenced with in CallExpressions', () => {
       const input = tags.stripIndent`
         class ApplicationModule {
@@ -439,6 +470,22 @@ describe('wrap enums and classes transformer', () => {
       expect(tags.oneLine`${transform(input)}`).toEqual(tags.oneLine`${output}`);
     });
 
+    it('should not wrap enum like object literal declarations', () => {
+      const input = tags.stripIndent`
+        const RendererStyleFlags3 = {
+            Important: 1,
+            DashCase: 2,
+        };
+        if (typeof RendererStyleFlags3 === 'object') {
+          RendererStyleFlags3[RendererStyleFlags3.Important] = 'DashCase';
+        }
+        RendererStyleFlags3[RendererStyleFlags3.Important] = 'Important';
+      `;
+      const output = input;
+
+      expect(tags.oneLine`${transform(input)}`).toEqual(tags.oneLine`${output}`);
+    });
+
     it('wraps ES2015 tsickle enums in IIFE', () => {
       const input = tags.stripIndent`
         const ChangeDetectionStrategy = {