Change decoratorsBeforeExport default to false (#8113)

packages/babel-generator/src/index.js

@@ -52,10 +52,7 @@ function normalizeOptions(code, opts): Format {
       style: "  ",
       base: 0,
     },
-    decoratorsBeforeExport:
-      opts.decoratorsBeforeExport === undefined
-        ? true
-        : opts.decoratorsBeforeExport,
+    decoratorsBeforeExport: !!opts.decoratorsBeforeExport,
   };
 
   if (format.minified) {

packages/babel-generator/test/fixtures/types/Decorator/output.js

@@ -32,15 +32,15 @@ class Foo {
 
 }
 
-@foo
-export default class Foo {
+export default @foo
+class Foo {
   bar() {
     class Baz {}
   }
 
 }
-@foo
-export class Foo {
+export @foo
+class Foo {
   bar() {
     class Baz {}
   }

packages/babel-parser/src/parser/statement.js

@@ -263,8 +263,7 @@ export default class StatementParser extends ExpressionParser {
         this.raise(
           this.state.start,
           "Using the export keyword between a decorator and a class is not allowed. " +
-            "Please use `export @dec class` instead, or set the " +
-            "'decoratorsBeforeExport' option to true.",
+            "Please use `export @dec class` instead.",
         );
       }
     } else if (!this.canHaveLeadingDecorator()) {

packages/babel-parser/test/fixtures/experimental/decorators-2/no-export-decorators-on-class/options.json

@@ -1,4 +1,4 @@
 {
   "sourceType": "module",
-  "throws": "Using the export keyword between a decorator and a class is not allowed. Please use `export @dec class` instead, or set the 'decoratorsBeforeExport' option to true. (2:0)"
+  "throws": "Using the export keyword between a decorator and a class is not allowed. Please use `export @dec class` instead. (2:0)"
 }

packages/babel-plugin-syntax-decorators/src/index.js

@@ -16,7 +16,7 @@ export default declare((api, options) => {
     );
   }
 
-  let { decoratorsBeforeExport } = options;
+  const { decoratorsBeforeExport } = options;
   if (decoratorsBeforeExport !== undefined) {
     if (legacy) {
       throw new Error(
@@ -26,8 +26,6 @@ export default declare((api, options) => {
     if (typeof decoratorsBeforeExport !== "boolean") {
       throw new Error("'decoratorsBeforeExport' must be a boolean.");
     }
-  } else if (!legacy) {
-    decoratorsBeforeExport = true;
   }
 
   return {

packages/babel-plugin-syntax-decorators/test/index.js

@@ -47,8 +47,8 @@ describe("'decoratorsBeforeExport' option", function() {
   const AFTER = "export @dec class Foo {}";
 
   // These are skipped
-  run(BEFORE, undefined, false);
-  run(AFTER, undefined, true);
+  run(BEFORE, undefined, true);
+  run(AFTER, undefined, false);
   run(BEFORE, true, false);
   run(AFTER, true, true);
   run(BEFORE, false, true);