[optimizeConstEnums] Inline const enum if only exported as type (#14723)

nicolo-ribaudo · web-flow · commit 184eeea9ba02 · 2022-07-05T23:05:44.000+02:00
diff --git a/packages/babel-plugin-transform-typescript/src/const-enum.ts b/packages/babel-plugin-transform-typescript/src/const-enum.ts
@@ -16,9 +16,13 @@ export default function transpileConstEnum(
     isExported = path.parent.body.some(
       stmt =>
         t.isExportNamedDeclaration(stmt) &&
+        stmt.exportKind !== "type" &&
         !stmt.source &&
         stmt.specifiers.some(
-          spec => t.isExportSpecifier(spec) && spec.local.name === name,
+          spec =>
+            t.isExportSpecifier(spec) &&
+            spec.exportKind !== "type" &&
+            spec.local.name === name,
         ),
     );
   }
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-and-value/input.ts b/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-and-value/input.ts
@@ -0,0 +1,9 @@
+const enum WhitespaceFlag {
+  before = 1 << 0,
+  after = 1 << 1,
+}
+
+export type { WhitespaceFlag as WF1 };
+export { WhitespaceFlag as WF2 };
+
+export const before = WhitespaceFlag.before;
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-and-value/output.mjs b/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-and-value/output.mjs
@@ -0,0 +1,6 @@
+var WhitespaceFlag = {
+  before: 1,
+  after: 2
+};
+export { WhitespaceFlag as WF2 };
+export const before = WhitespaceFlag.before;
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-no-deopt/input.ts b/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-no-deopt/input.ts
@@ -0,0 +1,9 @@
+const enum WhitespaceFlag {
+  before = 1 << 0,
+  after = 1 << 1,
+}
+
+export type { WhitespaceFlag as WF1 };
+export { type WhitespaceFlag as WF2 };
+
+export const before = WhitespaceFlag.before;
diff --git a/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-no-deopt/output.mjs b/packages/babel-plugin-transform-typescript/test/fixtures/optimize-const-enums/export-const-enum-type-no-deopt/output.mjs
@@ -0,0 +1,2 @@
+export {};
+export const before = 1;

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+export {};`
	`2`	`+export const before = 1;`