fix(types): expand custom endpoint type (#622)

Author: kuhe

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/endpointsV2/ParameterGenerator.java

@@ -109,10 +109,15 @@ public String toCodeString(boolean isClientContextParam) {
             buffer += "?";
         }
         buffer += ": ";
-        if (isClientContextParam) {
-            buffer += (tsParamType + "|" + "Provider<" + tsParamType + ">") + ";";
+
+        if (parameterName.equals("endpoint")) {
+            buffer += "string | Provider<string> | Endpoint | Provider<Endpoint> | EndpointV2 | Provider<EndpointV2>;";
         } else {
-            buffer += tsParamType + ";";
+            if (isClientContextParam) {
+                buffer += (tsParamType + "|" + "Provider<" + tsParamType + ">") + ";";
+            } else {
+                buffer += tsParamType + ";";
+            }
         }
         return buffer;
     }

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/endpointsV2/RuleSetParametersVisitor.java

@@ -64,6 +64,12 @@ public Void objectNode(ObjectNode node) {
 
             ParameterGenerator parameterGenerator = new ParameterGenerator(localKey, param);
 
+            if (localKey.equals("endpoint")) {
+                writer.addImport("Endpoint", null, "@aws-sdk/types");
+                writer.addImport("EndpointV2", null, "@aws-sdk/types");
+                writer.addImport("Provider", null, "@aws-sdk/types");
+            }
+
             if (writeDefaults) {
                 if (parameterGenerator.hasDefault()) {
                     writer.write(parameterGenerator.defaultAsCodeString());