feat(@angular-devkit/build-optimizer): update TypeScript to 2.7

Author: clydin

packages/angular_devkit/build_optimizer/package.json

@@ -14,7 +14,7 @@
   "dependencies": {
     "loader-utils": "^1.1.0",
     "source-map": "^0.5.6",
-    "typescript": "~2.6.2",
-    "webpack-sources": "^1.0.1"
+    "typescript": "~2.7.2",
+    "webpack-sources": "^1.1.0"
   }
 }

packages/angular_devkit/build_optimizer/src/transforms/class-fold.ts

@@ -162,15 +162,14 @@ function findClassStaticPropertyAssignments(
     }
 
     const decls = symbol.declarations;
-    if (decls === undefined || decls.length !== 1) {
+    if (decls == undefined || decls.length === 0) {
       return;
     }
-    const classIdx = classes
-      .map((clazz) => clazz.class).indexOf(decls[0] as ts.VariableDeclaration);
-    if (classIdx === -1) {
+
+    const hostClass = classes.find((clazz => decls.includes(clazz.class)));
+    if (!hostClass) {
       return;
     }
-    const hostClass = classes[classIdx];
     const statement: StatementData = { expressionStatement, hostClass };
 
     hostClass.statements.push(statement);