chore(codegen): use pagination factory in ddb document client

Author: pasoevi

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/DocumentClientPaginationGenerator.java

@@ -17,13 +17,9 @@
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.Optional;
-import software.amazon.smithy.codegen.core.CodegenException;
 import software.amazon.smithy.codegen.core.Symbol;
 import software.amazon.smithy.codegen.core.SymbolProvider;
 import software.amazon.smithy.model.Model;
-import software.amazon.smithy.model.knowledge.PaginatedIndex;
-import software.amazon.smithy.model.knowledge.PaginationInfo;
 import software.amazon.smithy.model.shapes.OperationShape;
 import software.amazon.smithy.model.shapes.ServiceShape;
 import software.amazon.smithy.typescript.codegen.TypeScriptDependency;
@@ -36,14 +32,13 @@ final class DocumentClientPaginationGenerator implements Runnable {
     static final String PAGINATION_FOLDER = "pagination";
 
     private final TypeScriptWriter writer;
-    private final PaginationInfo paginatedInfo;
 
     private final String operationTypeName;
     private final String inputTypeName;
     private final String outputTypeName;
 
     private final String operationName;
-    private final String methodName;
+
     private final String paginationType;
 
     DocumentClientPaginationGenerator(
@@ -65,14 +60,7 @@ final class DocumentClientPaginationGenerator implements Runnable {
 
         // e.g. listObjects
         this.operationName = operationTypeName.replace("Command", "");
-        this.methodName = Character.toLowerCase(operationName.charAt(0)) + operationName.substring(1);
         this.paginationType = DocumentClientUtils.CLIENT_FULL_NAME + "PaginationConfiguration";
-
-        PaginatedIndex paginatedIndex = PaginatedIndex.of(model);
-        Optional<PaginationInfo> paginationInfo = paginatedIndex.getPaginationInfo(service, operation);
-        this.paginatedInfo = paginationInfo.orElseThrow(() -> {
-            return new CodegenException("Expected Paginator to have pagination information.");
-        });
     }
 
     @Override
@@ -90,13 +78,13 @@ public void run() {
 
         // Import Pagination types
         writer.addImport("Paginator", "Paginator", TypeScriptDependency.SMITHY_TYPES);
+        writer.addImport("createPaginator", "createPaginator", TypeScriptDependency.SMITHY_CORE);
         writer.addRelativeImport(paginationType, paginationType,
             Paths.get(".", getInterfaceFilelocation().replace(".ts", "")));
 
         writer.writeDocs("@public");
         writer.write("export { Paginator }");
 
-        writeCommandRequest();
         writePager();
     }
 
@@ -134,71 +122,18 @@ static void generateServicePaginationInterfaces(TypeScriptWriter writer) {
         });
     }
 
-    private String destructurePath(String path) {
-        return "."  + path.replace(".", "!.");
-    }
-
     private void writePager() {
-        String inputTokenName = paginatedInfo.getPaginatedTrait().getInputToken().get();
-        String outputTokenName = paginatedInfo.getPaginatedTrait().getOutputToken().get();
-
-        writer.writeDocs("@public\n\n"
-            + String.format("@param %s - {@link %s}%n", inputTypeName, inputTypeName)
-            + String.format("@returns {@link %s}%n", outputTypeName)
-            );
-        writer.openBlock(
-                "export async function* paginate$L(config: $L, input: $L, ...additionalArguments: any): Paginator<$L>{",
-                "}",  operationName, paginationType, inputTypeName, outputTypeName, () -> {
-            String destructuredInputTokenName = destructurePath(inputTokenName);
-            writer.write("// ToDo: replace with actual type instead of typeof input$L", destructuredInputTokenName);
-            writer.write("let token: typeof input$L | undefined = config.startingToken || undefined;",
-                    destructuredInputTokenName);
-
-            writer.write("let hasNext = true;");
-            writer.write("let page: $L;", outputTypeName);
-            writer.openBlock("while (hasNext) {", "}", () -> {
-                writer.write("input$L = token;", destructuredInputTokenName);
-
-                if (paginatedInfo.getPageSizeMember().isPresent()) {
-                    String pageSize = paginatedInfo.getPageSizeMember().get().getMemberName();
-                    writer.write("input[$S] = config.pageSize;", pageSize);
-                }
-
-                writer.openBlock("if (config.client instanceof $L) {", "}", DocumentClientUtils.CLIENT_NAME,
-                    () -> {
-                        writer.write(
-                            "page = await makePagedClientRequest(config.client, input, ...additionalArguments);");
-                    }
-                );
-                writer.openBlock("else {", "}", () -> {
-                    writer.write("throw new Error(\"Invalid client, expected $L | $L\");",
-                            DocumentClientUtils.CLIENT_FULL_NAME, DocumentClientUtils.CLIENT_NAME);
-                });
-
-                writer.write("yield page;");
-                writer.write("token = page$L;", destructurePath(outputTokenName));
-
-                writer.write("hasNext = !!(token);");
-            });
-
-            writer.write("// @ts-ignore");
-            writer.write("return undefined;");
-        });
-    }
-
-
-    /**
-     * Paginated command that calls CommandClient().send({...}) under the hood. This is meant for client side (browser)
-     * environments and does not generally expose the entire service.
-     */
-    private void writeCommandRequest() {
-        writer.writeDocs("@internal");
-        writer.openBlock(
-                "const makePagedClientRequest = async (client: $L, input: $L, ...args: any): Promise<$L> => {",
-                "}", DocumentClientUtils.CLIENT_NAME, inputTypeName,
-                outputTypeName, () -> {
-            writer.write("// @ts-ignore");
-            writer.write("return await client.send(new $L(input), ...args);", operationTypeName);
-        });
+        writer.writeDocs("@public");
+        writer.write("""
+export const paginate$1L: (
+  config: $2L,
+  input: $3L,
+  ...additionalArguments: any
+) => Paginator<$4L> = createPaginator<
+  $2L,
+  $3L,
+  $4L
+>(DynamoDBDocumentClient, $1LCommand, "ExclusiveStartKey", "LastEvaluatedKey", "Limit");
+        """, operationName, paginationType, inputTypeName, outputTypeName);
     }
 }