Minor refactoring and updating readme (#5370)

Author: zoewangg

migration-tool/README.md

@@ -1,7 +1,7 @@
 # AWS SDK for Java v2 Migration Tool
 
 ## Description
-This is a migration tool to automate migration from AWS SDK for Java v1 to AWS SDK for Java v2. 
+This is a migration tool to automate migration from AWS SDK for Java v1 to AWS SDK for Java v2.
 It uses [OpenRewrite][open-rewrite].
 
 ## Usage
@@ -17,7 +17,7 @@ find the latest version.
 
 ```
 mvn org.openrewrite.maven:rewrite-maven-plugin:dryRun \
-  -Drewrite.recipeArtifactCoordinates=software.amazon.awssdk:migration-tool:{sdkversion}
+  -Drewrite.recipeArtifactCoordinates=software.amazon.awssdk:migration-tool:{sdkversion} \
   -Drewrite.activeRecipes=software.amazon.awssdk.UpgradeJavaSdk2
 ```
 
@@ -27,11 +27,35 @@ With this mode, it runs the SDK recipes and applies the changes locally.
 
 ```
 mvn org.openrewrite.maven:rewrite-maven-plugin:run \
-  -Drewrite.recipeArtifactCoordinates=software.amazon.awssdk:migration-tool:{sdkversion}
+  -Drewrite.recipeArtifactCoordinates=software.amazon.awssdk:migration-tool:{sdkversion} \
   -Drewrite.activeRecipes=software.amazon.awssdk.UpgradeJavaSdk2
 ```
 
+
+## Development
+
+To build this module locally for fast development, run the following command.
+
+```
+mvn clean install -pl :bom-internal,:bom,:migration-tool -P quick --am
+```
+
+### Testing
+
+There are two types of tests available: unit tests and end-to-end functional tests.
+- Unit tests
+
+Unit tests reside in the test folder in this module. They use [RewriteTest][rewrite-test] interface
+
+- End-to-end functional tests
+
+End-to-end functional tests are in [migration-tool-tests module][migration-tool-tests]. It contains
+sample applications using the AWS SDK for Java v1 and compares the transformed code with the expected v2 
+code and ensures it compiles.
+
 [open-rewrite]: https://docs.openrewrite.org/
 [open-rewrite-usage]: https://docs.openrewrite.org/running-recipes
 [open-rewrite-plugin]: https://docs.openrewrite.org/reference/rewrite-maven-plugin
-[maven-central]: https://central.sonatype.com/artifact/software.amazon.awssdk/migration-tool
+[maven-central]: https://central.sonatype.com/artifact/software.amazon.awssdk/migration-tool
+[rewrite-test]:https://docs.openrewrite.org/authoring-recipes/recipe-testing#rewritetest-interface
+[migration-tool-tests]:../test/migration-tool-tests

migration-tool/src/main/java/software/amazon/awssdk/migration/internal/recipe/V1GetterToV2.java

@@ -21,10 +21,8 @@
 import org.openrewrite.Recipe;
 import org.openrewrite.TreeVisitor;
 import org.openrewrite.java.JavaIsoVisitor;
-import org.openrewrite.java.tree.Expression;
 import org.openrewrite.java.tree.J;
 import org.openrewrite.java.tree.JavaType;
-import org.openrewrite.java.tree.TypeUtils;
 import software.amazon.awssdk.annotations.SdkInternalApi;
 import software.amazon.awssdk.migration.internal.utils.NamingUtils;
 
@@ -51,17 +49,14 @@ private static class V1GetterToV2Visitor extends JavaIsoVisitor<ExecutionContext
         public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, ExecutionContext executionContext) {
             method = super.visitMethodInvocation(method, executionContext);
 
-            JavaType selectType;
-
-            Expression select = method.getSelect();
+            JavaType.Method methodType = method.getMethodType();
 
-            if (select == null || select.getType() == null) {
+            if (methodType == null) {
                 return method;
             }
-            selectType = select.getType();
 
             String methodName = method.getSimpleName();
-            JavaType.FullyQualified fullyQualified = TypeUtils.asFullyQualified(selectType);
+            JavaType.FullyQualified fullyQualified = methodType.getDeclaringType();
 
             if (!shouldChangeGetter(fullyQualified)) {
                 return method;
@@ -71,21 +66,11 @@ public J.MethodInvocation visitMethodInvocation(J.MethodInvocation method, Execu
                 methodName = NamingUtils.removeGet(methodName);
             }
 
-            JavaType.Method methodType = method.getMethodType();
-
-            if (methodType != null) {
-                methodType = methodType.withName(methodName)
-                       .withReturnType(selectType);
-
-                if (fullyQualified != null) {
-                    methodType = methodType.withDeclaringType(fullyQualified);
-                }
-
-                method = method.withName(method.getName()
-                                               .withSimpleName(methodName)
-                                               .withType(methodType))
-                               .withMethodType(methodType);
-            }
+            methodType = methodType.withName(methodName);
+            method = method.withName(method.getName()
+                                           .withSimpleName(methodName)
+                                           .withType(methodType))
+                           .withMethodType(methodType);
 
             return method;
         }