Adds OperatingSystem enum. (#4)

Author: coollog

skaffold-plugins-core/src/main/java/com/google/cloud/tools/skaffold/filesystem/OperatingSystem.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2018 Google LLC. All rights reserved.
+ *
+ * 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 com.google.cloud.tools.skaffold.filesystem;
+
+import java.util.Locale;
+import java.util.Properties;
+
+/** Gets information about the operating system. */
+public enum OperatingSystem {
+  LINUX,
+  MAC_OS,
+  WINDOWS;
+
+  /**
+   * Resolves the operating system type.
+   *
+   * @return the {@link OperatingSystem}
+   */
+  public static OperatingSystem resolve() {
+    return resolve(System.getProperties());
+  }
+
+  static OperatingSystem resolve(Properties properties) {
+    String rawOsName = properties.getProperty("os.name");
+    String osName = rawOsName.toLowerCase(Locale.ENGLISH);
+
+    if (osName.contains("linux")) {
+      return LINUX;
+    }
+    if (osName.contains("windows")) {
+      return WINDOWS;
+    }
+    if (osName.contains("mac") || osName.contains("darwin")) {
+      return MAC_OS;
+    }
+
+    throw new IllegalStateException("Unknown OS: " + rawOsName);
+  }
+}

skaffold-plugins-core/src/main/java/com/google/cloud/tools/skaffold/filesystem/UserCacheHome.java

@@ -20,7 +20,6 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.Locale;
 import java.util.Map;
 import java.util.Properties;
 import java.util.logging.Logger;
@@ -51,7 +50,7 @@ public static Path getCacheHome() {
    * Returns {@code $XDG_CACHE_HOME}, if available, or resolves the OS-specific user cache home
    * based.
    *
-   * <p>For Linus, this is {@code $HOME/.cache/}.
+   * <p>For Linux, this is {@code $HOME/.cache/}.
    *
    * <p>For Windows, this is {@code %LOCALAPPDATA%}.
    *
@@ -70,37 +69,39 @@ static Path getCacheHome(Properties properties, Map<String, String> environment)
     Path userHomeDirectory = Paths.get(userHome);
     Path xdgPath = userHomeDirectory.resolve(".cache");
 
-    String rawOsName = properties.getProperty("os.name");
-    String osName = rawOsName.toLowerCase(Locale.ENGLISH);
+    OperatingSystem operatingSystem = OperatingSystem.resolve(properties);
 
-    if (osName.contains("linux")) {
-      return xdgPath;
-
-    } else if (osName.contains("windows")) {
-      // Use %LOCALAPPDATA% for Windows.
-      String localAppDataEnv = environment.get("LOCALAPPDATA");
-      if (localAppDataEnv == null || localAppDataEnv.trim().isEmpty()) {
-        logger.warning("LOCALAPPDATA environment is invalid or missing");
-        return xdgPath;
-      }
-      Path localAppData = Paths.get(localAppDataEnv);
-      if (!Files.exists(localAppData)) {
-        logger.warning(localAppData + " does not exist");
+    switch (operatingSystem) {
+      case LINUX:
         return xdgPath;
-      }
-      return localAppData;
 
-    } else if (osName.contains("mac") || osName.contains("darwin")) {
-      // Use '~/Library/Application Support/' for macOS.
-      Path applicationSupport = userHomeDirectory.resolve("Library").resolve("Application Support");
-      if (!Files.exists(applicationSupport)) {
-        logger.warning(applicationSupport + " does not exist");
-        return xdgPath;
-      }
-      return applicationSupport;
-    }
+      case WINDOWS:
+        // Use %LOCALAPPDATA% for Windows.
+        String localAppDataEnv = environment.get("LOCALAPPDATA");
+        if (localAppDataEnv == null || localAppDataEnv.trim().isEmpty()) {
+          logger.warning("LOCALAPPDATA environment is invalid or missing");
+          return xdgPath;
+        }
+        Path localAppData = Paths.get(localAppDataEnv);
+        if (!Files.exists(localAppData)) {
+          logger.warning(localAppData + " does not exist");
+          return xdgPath;
+        }
+        return localAppData;
+
+      case MAC_OS:
+        // Use '~/Library/Application Support/' for macOS.
+        Path applicationSupport =
+            userHomeDirectory.resolve("Library").resolve("Application Support");
+        if (!Files.exists(applicationSupport)) {
+          logger.warning(applicationSupport + " does not exist");
+          return xdgPath;
+        }
+        return applicationSupport;
 
-    throw new IllegalStateException("Unknown OS: " + rawOsName);
+      default:
+        throw new IllegalStateException("unreachable");
+    }
   }
 
   private UserCacheHome() {}

skaffold-plugins-core/src/test/java/com/google/cloud/tools/skaffold/filesystem/OperatingSystemTest.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2018 Google LLC. All rights reserved.
+ *
+ * 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 com.google.cloud.tools.skaffold.filesystem;
+
+import java.util.Properties;
+import org.junit.Assert;
+import org.junit.Test;
+
+/** Tests for {@link OperatingSystem}. */
+public class OperatingSystemTest {
+
+  @Test
+  public void testLinux() {
+    Properties fakeProperties = new Properties();
+    fakeProperties.setProperty("os.name", "os is LiNuX");
+    Assert.assertEquals(OperatingSystem.LINUX, OperatingSystem.resolve(fakeProperties));
+  }
+
+  @Test
+  public void testMacOs_mac() {
+    Properties fakeProperties = new Properties();
+    fakeProperties.setProperty("os.name", "os is mAc");
+    Assert.assertEquals(OperatingSystem.MAC_OS, OperatingSystem.resolve(fakeProperties));
+  }
+
+  @Test
+  public void testMacOs_darwin() {
+    Properties fakeProperties = new Properties();
+    fakeProperties.setProperty("os.name", "os is DaRwIn");
+    Assert.assertEquals(OperatingSystem.MAC_OS, OperatingSystem.resolve(fakeProperties));
+  }
+
+  @Test
+  public void testWindows() {
+    Properties fakeProperties = new Properties();
+    fakeProperties.setProperty("os.name", "os is WiNdOwS");
+    Assert.assertEquals(OperatingSystem.WINDOWS, OperatingSystem.resolve(fakeProperties));
+  }
+
+  @Test
+  public void testUnknown() {
+    Properties fakeProperties = new Properties();
+    fakeProperties.setProperty("os.name", "UnKnOwN");
+    try {
+      OperatingSystem.resolve(fakeProperties);
+      Assert.fail("Resolve should have failed");
+
+    } catch (IllegalStateException ex) {
+      Assert.assertEquals("Unknown OS: UnKnOwN", ex.getMessage());
+    }
+  }
+}