Fix export all bug and add NamespaceExport support (#937)

hazzard993 · web-flow · commit a3bfc2dfce57 · 2020-12-14T20:45:42.000+01:00
* Fix export all bug #927 * Support NamespaceExport #928 * Update snapshots * Add unsafe Lua name NamespaceExport test * Add comments to transformExportAll and add export default if NamespaceExport
diff --git a/src/transformation/visitors/modules/export.ts b/src/transformation/visitors/modules/export.ts
@@ -36,34 +36,72 @@ export const transformExportAssignment: FunctionVisitor<ts.ExportAssignment> = (
     }
 };
 
-function transformExportAllFrom(context: TransformationContext, node: ts.ExportDeclaration): lua.Statement | undefined {
+function transformExportAll(context: TransformationContext, node: ts.ExportDeclaration): lua.Statement | undefined {
     assert(node.moduleSpecifier);
 
     if (!context.resolver.moduleExportsSomeValue(node.moduleSpecifier)) {
         return undefined;
     }
 
     const moduleRequire = createModuleRequire(context, node.moduleSpecifier);
-    const tempModuleIdentifier = lua.createIdentifier("____export");
 
+    // export * as ns from "...";
+    // exports.ns = require(...)
+    if (node.exportClause && ts.isNamespaceExport(node.exportClause)) {
+        const assignToExports = lua.createAssignmentStatement(
+            lua.createTableIndexExpression(
+                createExportsIdentifier(),
+                lua.createStringLiteral(node.exportClause.name.text)
+            ),
+            moduleRequire
+        );
+        return assignToExports;
+    }
+
+    // export * from "...";
+    // exports all values EXCEPT "default" from "..."
+    const result: lua.Statement[] = [];
+
+    // local ____export = require(...)
+    const tempModuleIdentifier = lua.createIdentifier("____export");
     const declaration = lua.createVariableDeclarationStatement(tempModuleIdentifier, moduleRequire);
+    result.push(declaration);
 
+    // ____exports[____exportKey] = ____exportValue
     const forKey = lua.createIdentifier("____exportKey");
     const forValue = lua.createIdentifier("____exportValue");
+    const leftAssignment = lua.createAssignmentStatement(
+        lua.createTableIndexExpression(createExportsIdentifier(), forKey),
+        forValue
+    );
 
-    const body = lua.createBlock([
-        lua.createAssignmentStatement(lua.createTableIndexExpression(createExportsIdentifier(), forKey), forValue),
-    ]);
+    // if key ~= "default" then
+    //  -- export the value, do not export "default" values
+    // end
+    const ifBody = lua.createBlock([leftAssignment]);
+    const ifStatement = lua.createIfStatement(
+        lua.createBinaryExpression(
+            lua.cloneIdentifier(forKey),
+            lua.createStringLiteral("default"),
+            lua.SyntaxKind.InequalityOperator
+        ),
+        ifBody
+    );
 
+    // for ____exportKey, ____exportValue in ____export do
+    //  -- export ____exportValue, unless ____exportKey is "default"
+    // end
     const pairsIdentifier = lua.createIdentifier("pairs");
     const forIn = lua.createForInStatement(
-        body,
+        lua.createBlock([ifStatement]),
         [lua.cloneIdentifier(forKey), lua.cloneIdentifier(forValue)],
         [lua.createCallExpression(pairsIdentifier, [lua.cloneIdentifier(tempModuleIdentifier)])]
     );
 
+    result.push(forIn);
+
     // Wrap this in a DoStatement to prevent polluting the scope.
-    return lua.createDoStatement([declaration, forIn], node);
+    return lua.createDoStatement(result, node);
 }
 
 const isDefaultExportSpecifier = (node: ts.ExportSpecifier) =>
@@ -127,7 +165,7 @@ export const getExported = (context: TransformationContext, exportSpecifiers: ts
 export const transformExportDeclaration: FunctionVisitor<ts.ExportDeclaration> = (node, context) => {
     if (!node.exportClause) {
         // export * from "...";
-        return transformExportAllFrom(context, node);
+        return transformExportAll(context, node);
     }
 
     if (!context.resolver.isValueAliasDeclaration(node)) {
@@ -136,7 +174,7 @@ export const transformExportDeclaration: FunctionVisitor<ts.ExportDeclaration> =
 
     if (ts.isNamespaceExport(node.exportClause)) {
         // export * as ns from "...";
-        throw new Error("NamespaceExport is not supported");
+        return transformExportAll(context, node);
     }
 
     const exportSpecifiers = getExported(context, node.exportClause);
diff --git a/test/translation/__snapshots__/transformation.spec.ts.snap b/test/translation/__snapshots__/transformation.spec.ts.snap
@@ -64,7 +64,9 @@ ____exports.uwv = xyz
 do
     local ____export = require(\\"xyz\\")
     for ____exportKey, ____exportValue in pairs(____export) do
-        ____exports[____exportKey] = ____exportValue
+        if ____exportKey ~= \\"default\\" then
+            ____exports[____exportKey] = ____exportValue
+        end
     end
 end
 do
diff --git a/test/unit/modules/modules.spec.ts b/test/unit/modules/modules.spec.ts
@@ -275,3 +275,32 @@ test("export default function with future reference", () => {
         .setReturnExport("result")
         .expectToMatchJsResult();
 });
+
+const moduleFile = `
+export default true;
+export const foo = "bar";
+`;
+
+test("export all does not include default", () => {
+    util.testBundle`
+        export * from "./module";
+    `
+        .addExtraFile("module.ts", moduleFile)
+        .expectToEqual({ foo: "bar" });
+});
+
+test("namespace export does not include default", () => {
+    util.testBundle`
+        export * as result from "./module";
+    `
+        .addExtraFile("module.ts", moduleFile)
+        .expectToEqual({ result: { default: true, foo: "bar" } });
+});
+
+test("namespace export with unsafe Lua name", () => {
+    util.testBundle`
+        export * as $$$ from "./module";
+    `
+        .addExtraFile("module.ts", moduleFile)
+        .expectToEqual({ $$$: { default: true, foo: "bar" } });
+});
