From f6d9605a352add2f7e68f9f78e178ce5f76fae8e Mon Sep 17 00:00:00 2001
From: adventure-yunfei <adventure-yunfei@users.noreply.github.com>
Date: Sun, 16 Feb 2020 01:51:49 +0800
Subject: [PATCH] local module import: support dts rollup

---
 apps/api-extractor/src/collector/Collector.ts |  3 ++
 .../src/generators/DtsRollupGenerator.ts      | 34 ++++++++++++++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/apps/api-extractor/src/collector/Collector.ts b/apps/api-extractor/src/collector/Collector.ts
index ecb6ee79f85..865bcd6e805 100644
--- a/apps/api-extractor/src/collector/Collector.ts
+++ b/apps/api-extractor/src/collector/Collector.ts
@@ -428,6 +428,9 @@ export class Collector {
       });
     } else if (astEntity instanceof AstImportInternal) {
       this.astSymbolTable.fetchAstModuleExportInfo(astEntity.astModule).exportedLocalEntities.forEach((exportedEntity: AstEntity) => {
+        // Create a CollectorEntity for each top-level export of AstImportInternal entity
+        this._createCollectorEntity(exportedEntity, undefined);
+
         this._createEntityForIndirectReferences(exportedEntity, alreadySeenAstEntities); // TODO- create entity for module export
       });
     }
diff --git a/apps/api-extractor/src/generators/DtsRollupGenerator.ts b/apps/api-extractor/src/generators/DtsRollupGenerator.ts
index dee02f91c55..eb9b4d9a60f 100644
--- a/apps/api-extractor/src/generators/DtsRollupGenerator.ts
+++ b/apps/api-extractor/src/generators/DtsRollupGenerator.ts
@@ -133,7 +133,39 @@ export class DtsRollupGenerator {
           }
         }
       } else if (entity.astEntity instanceof AstImportInternal) {
-        throw new InternalError('Unsupported AstImportInternal');
+        if (!entity.astEntity.astModule.astModuleExportInfo) {
+          // This should never happen
+          throw new InternalError('local imported module has not been parsed.');
+        }
+        if (!entity.nameForEmit) {
+          // This should never happen
+          throw new InternalError('referencedEntry.nameForEmit is undefined');
+        }
+        // manually generate typings for local imported module
+        stringWriter.writeLine();
+        if (entity.shouldInlineExport) {
+          stringWriter.write('export ');
+        }
+        stringWriter.writeLine(`declare namespace ${entity.nameForEmit} {`);
+
+        // all local exports of local imported module are just references to top-level declarations
+        stringWriter.writeLine('  export {');
+        entity.astEntity.astModule.astModuleExportInfo.exportedLocalEntities.forEach((exportedEntity, exportedName) => {
+          const collectorEntity: CollectorEntity | undefined = collector.tryGetCollectorEntity(exportedEntity);
+          if (!collectorEntity) {
+            // This should never happen
+            // top-level exports of local imported module should be added as collector entities before
+            throw new Error(`Cannot find collector entity for ${entity.nameForEmit}.${exportedEntity.localName}`);
+          }
+          if (collectorEntity.nameForEmit === exportedName) {
+            stringWriter.writeLine(`    ${collectorEntity.nameForEmit},`);
+          } else {
+            stringWriter.writeLine(`    ${collectorEntity.nameForEmit} as ${exportedName},`);
+          }
+        });
+        stringWriter.writeLine('  }'); // end of "export { ... }"
+
+        stringWriter.writeLine('}'); // end of "declare namespace { ... }"
       }
 
       if (!entity.shouldInlineExport) {