Merge pull request #1468 from wind57/more-changes

first commit

util/src/main/java/io/kubernetes/client/apimachinery/GroupVersion.java

@@ -12,24 +12,24 @@
 */
 package io.kubernetes.client.apimachinery;
 
+import static io.kubernetes.client.util.Preconditions.precondition;
+
 import io.kubernetes.client.common.KubernetesObject;
 import io.kubernetes.client.util.Strings;
 import java.util.Objects;
 
 public class GroupVersion {
 
+  private static final GroupVersion GROUP_VERSION_V1 = new GroupVersion("", "v1");
+
   public static GroupVersion parse(String apiVersion) {
-    if (Strings.isNullOrEmpty(apiVersion)) {
-      throw new IllegalArgumentException("No apiVersion found on object");
-    }
     if ("v1".equals(apiVersion)) {
       // legacy api group
-      return new GroupVersion("", "v1");
+      return GROUP_VERSION_V1;
     }
+    precondition(apiVersion, Strings::isNullOrEmpty, () -> "apiVersion can not be null");
     String[] parts = apiVersion.split("/");
-    if (parts.length != 2) {
-      throw new IllegalArgumentException("Invalid apiVersion found on object: " + apiVersion);
-    }
+    precondition(parts, x -> x.length != 2, () -> "Invalid apiVersion: " + apiVersion);
     return new GroupVersion(parts[0], parts[1]);
   }
 
@@ -38,14 +38,8 @@ public static GroupVersion parse(KubernetesObject obj) {
   }
 
   public GroupVersion(String group, String version) {
-    if (group == null) {
-      throw new IllegalArgumentException("group must not be null");
-    }
-    if (version == null) {
-      throw new IllegalArgumentException("version must not be null");
-    }
-    this.group = group;
-    this.version = version;
+    this.group = precondition(group, Objects::isNull, () -> "group must not be null");
+    this.version = precondition(version, Objects::isNull, () -> "version must not be null");
   }
 
   private final String group;

util/src/main/java/io/kubernetes/client/util/Preconditions.java

@@ -0,0 +1,45 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package io.kubernetes.client.util;
+
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+
+/**
+ * support for different invariant checks, like for a example a non-null argument being passed to a
+ * method that does not support nulls.
+ *
+ * @author wind57
+ */
+public final class Preconditions {
+
+  private Preconditions() {
+    throw new AssertionError("not supported");
+  }
+
+  /**
+   * @param validate argument to be validated
+   * @param predicate to check against
+   * @param errorSupplier the error message generator
+   * @param <T>
+   * @return T if Predicate does not match
+   * @throws IllegalArgumentException if predicate returns true
+   */
+  public static <T> T precondition(
+      T validate, Predicate<? super T> predicate, Supplier<String> errorSupplier) {
+    if (predicate.test(validate)) {
+      throw new IllegalArgumentException(errorSupplier.get());
+    }
+    return validate;
+  }
+}

util/src/main/java/io/kubernetes/client/util/Strings.java

@@ -14,10 +14,14 @@
 
 import javax.annotation.Nullable;
 
-public class Strings {
+public final class Strings {
+
+  private Strings() {
+    throw new AssertionError("not supported");
+  }
 
   public static boolean isNullOrEmpty(String value) {
-    return value == null || value.length() == 0;
+    return value == null || value.isEmpty();
   }
 
   public static String nullToEmpty(@Nullable String string) {

util/src/test/java/io/kubernetes/client/apimachinery/GroupVersionTest.java

@@ -12,6 +12,8 @@
 */
 package io.kubernetes.client.apimachinery;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.*;
 
 import io.kubernetes.client.openapi.models.V1Deployment;
@@ -21,17 +23,37 @@
 public class GroupVersionTest {
 
   @Test
-  public void parse() {
-    assertEquals(new GroupVersion("", "v1"), GroupVersion.parse(new V1Pod().apiVersion("v1")));
-    assertEquals(
-        new GroupVersion("apps", "v1"),
-        GroupVersion.parse(new V1Deployment().apiVersion("apps/v1")));
-    assertThrows(
-        IllegalArgumentException.class,
-        () -> {
-          GroupVersion.parse(new V1Pod());
-          GroupVersion.parse(new V1Pod().apiVersion(null));
-          GroupVersion.parse(new V1Pod().apiVersion("foo/bar/f"));
-        });
+  public void parseV1() {
+    GroupVersion left = new GroupVersion("", "v1");
+    GroupVersion right = GroupVersion.parse(new V1Pod().apiVersion("v1"));
+    assertThat(left).isEqualTo(right);
+  }
+
+  @Test
+  public void parseAppsV1() {
+    GroupVersion left = new GroupVersion("apps", "v1");
+    GroupVersion right = GroupVersion.parse(new V1Deployment().apiVersion("apps/v1"));
+    assertThat(left).isEqualTo(right);
+  }
+
+  @Test
+  public void parseInvalid1() {
+    assertThatThrownBy(() -> GroupVersion.parse(new V1Pod()))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("apiVersion can not be null");
+  }
+
+  @Test
+  public void parseInvalid2() {
+    assertThatThrownBy(() -> GroupVersion.parse(new V1Pod().apiVersion(null)))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("apiVersion can not be null");
+  }
+
+  @Test
+  public void parseInvalid3() {
+    assertThatThrownBy(() -> GroupVersion.parse(new V1Pod().apiVersion("foo/bar/f")))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("Invalid apiVersion: foo/bar/f");
   }
 }

util/src/test/java/io/kubernetes/client/util/PreconditionsTest.java

@@ -0,0 +1,36 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+package io.kubernetes.client.util;
+
+import static io.kubernetes.client.util.Preconditions.precondition;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+
+public class PreconditionsTest {
+
+  @Test
+  public void testEmptyString() {
+    assertThatThrownBy(
+            () -> precondition("", Strings::isNullOrEmpty, () -> "string can not be empty"))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("string can not be empty");
+  }
+
+  @Test
+  public void testNonEmptyString() {
+    String abc = precondition("abc", Strings::isNullOrEmpty, () -> "string can not be empty");
+    Assertions.assertThat(abc).isEqualTo("abc");
+  }
+}