Add a plugin test runner and a test for types-codegen simple types (#855)

* Add a plugin test runner and a test for types-codegen simple types

* Address review comments

* Updates after merge from upstream/main

* Make spotless happy

* Comment test that should be disabled by default

Author: sugmanue

codegen/plugins/types-codegen/build.gradle.kts

@@ -7,4 +7,8 @@ description = "This module provides the codegen plugin for Smithy java type code
 extra["displayName"] = "Smithy :: Java :: Codegen :: Types"
 extra["moduleName"] = "software.amazon.smithy.java.codegen.types"
 
+dependencies {
+    testImplementation(project(":codegen:test-utils"))
+}
+
 addGenerateSrcsTask("software.amazon.smithy.java.codegen.types.TestJavaTypeCodegenRunner")

codegen/plugins/types-codegen/src/test/java/software/amazon/smithy/java/codegen/types/TypesCodegenPluginTest.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.java.codegen.types;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static software.amazon.smithy.java.codegen.test.PluginTestRunner.addTestCasesFromUrl;
+import static software.amazon.smithy.java.codegen.test.PluginTestRunner.findGotContent;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collection;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import software.amazon.smithy.java.codegen.test.PluginTestRunner.TestCase;
+
+public class TypesCodegenPluginTest {
+
+    @ParameterizedTest(name = "[{index}] => {0}")
+    @MethodSource("testCases")
+    public void runTestCase(TestCase test) {
+        test.builder().build();
+        var got = test.manifests().stream().flatMap(x -> x.getFiles().stream()).collect(Collectors.toSet());
+        for (var expected : test.expectedToContents().keySet()) {
+            var found = findExpected(expected, got);
+            assertNotNull(found, "Expected to find " + expected + " in the manifest");
+            var contents = findGotContent(found, test);
+            assertTrue(contents.isPresent());
+            assertEquals(test.expectedToContents().get(expected), contents.get());
+        }
+    }
+
+    // Uncomment this test to render the java files when we there are changes to the codegen logic.
+    // @ParameterizedTest(name = "[{index}] => {0}") @MethodSource("testCases")
+    public void renderExpected(TestCase test) throws IOException {
+        test.builder().build();
+        var got = test.manifests().stream().flatMap(x -> x.getFiles().stream()).collect(Collectors.toSet());
+        for (var expected : test.expectedToContents().keySet()) {
+            var found = findExpected(expected, got);
+            assertNotNull(found);
+            var contents = findGotContent(found, test);
+            var expectedFile = new File("/tmp/rendered/" + test + "/expected" + expected);
+            expectedFile.getParentFile().mkdirs();
+            Files.write(expectedFile.toPath(), contents.get().getBytes(StandardCharsets.UTF_8));
+        }
+    }
+
+    private Path findExpected(String expected, Set<Path> manifestFiles) {
+        return manifestFiles.stream().filter(path -> path.toString().contains(expected)).findFirst().orElse(null);
+    }
+
+    public static Collection<TestCase> testCases() {
+        return addTestCasesFromUrl(TypesCodegenPluginTest.class.getResource("test-cases"));
+    }
+}