Introduce a CapabilitiesUtils class for common operations on Capabili…

…ties

java/client/src/org/openqa/selenium/remote/CapabilitiesUtils.java

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+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you 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 org.openqa.selenium.remote;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import org.openqa.selenium.Capabilities;
+import org.openqa.selenium.ImmutableCapabilities;
+import org.openqa.selenium.Proxy;
+import org.openqa.selenium.internal.Require;
+import org.openqa.selenium.remote.session.CapabilitiesFilter;
+import org.openqa.selenium.remote.session.CapabilityTransform;
+import org.openqa.selenium.remote.session.ChromeFilter;
+import org.openqa.selenium.remote.session.EdgeFilter;
+import org.openqa.selenium.remote.session.FirefoxFilter;
+import org.openqa.selenium.remote.session.InternetExplorerFilter;
+import org.openqa.selenium.remote.session.OperaFilter;
+import org.openqa.selenium.remote.session.ProxyTransform;
+import org.openqa.selenium.remote.session.SafariFilter;
+import org.openqa.selenium.remote.session.StripAnyPlatform;
+import org.openqa.selenium.remote.session.W3CPlatformNameNormaliser;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Queue;
+import java.util.ServiceLoader;
+import java.util.Set;
+import java.util.TreeMap;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.openqa.selenium.remote.CapabilityType.PLATFORM;
+import static org.openqa.selenium.remote.CapabilityType.PLATFORM_NAME;
+import static org.openqa.selenium.remote.CapabilityType.PROXY;
+
+public class CapabilitiesUtils {
+
+  private static final Predicate<String> ACCEPTED_W3C_PATTERNS = new AcceptedW3CCapabilityKeys();
+
+  private CapabilitiesUtils() {
+    // Helper class
+  }
+
+  public static Stream<Capabilities> makeW3CSafe(Capabilities possiblyInvalidCapabilities) {
+    Require.nonNull("Capabilities", possiblyInvalidCapabilities);
+
+    return makeW3CSafe(possiblyInvalidCapabilities.asMap()).map(ImmutableCapabilities::new);
+  }
+
+  public static Stream<Map<String, Object>> makeW3CSafe(Map<String, Object> possiblyInvalidCapabilities) {
+    Require.nonNull("Capabilities", possiblyInvalidCapabilities);
+
+    Set<CapabilitiesFilter> adapters = getCapabilityFilters();
+
+    // If there's an OSS value, generate a stream of capabilities from that using the transforms,
+    // then add magic to generate each of the w3c capabilities. For the sake of simplicity, we're
+    // going to make the (probably wrong) assumption we can hold all of the firstMatch values and
+    // alwaysMatch value in memory at the same time.
+    Map<String, Object> oss = convertOssToW3C(possiblyInvalidCapabilities);
+    Stream<Map<String, Object>> fromOss;
+    Set<String> usedKeys = new HashSet<>();
+
+    // Are there any values we care want to pull out into a mapping of their own?
+    List<Map<String, Object>> firsts = adapters.stream()
+      .map(adapter -> adapter.apply(oss))
+      .filter(Objects::nonNull)
+      .filter(map -> !map.isEmpty())
+      .map(
+        map -> map.entrySet().stream()
+          .filter(entry -> entry.getKey() != null)
+          .filter(entry -> ACCEPTED_W3C_PATTERNS.test(entry.getKey()))
+          .filter(entry -> entry.getValue() != null)
+          .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue)))
+      .peek(map -> usedKeys.addAll(map.keySet()))
+      .collect(ImmutableList.toImmutableList());
+    if (firsts.isEmpty()) {
+      firsts = ImmutableList.of(ImmutableMap.of());
+    }
+
+    // Are there any remaining unused keys?
+    Map<String, Object> always = oss.entrySet().stream()
+      .filter(entry -> !usedKeys.contains(entry.getKey()))
+      .filter(entry -> entry.getValue() != null)
+      .collect(ImmutableMap.toImmutableMap(Map.Entry::getKey, Map.Entry::getValue));
+
+    // Firsts contains at least one entry, always contains everything else. Let's combine them
+    // into the stream to form a unified set of capabilities. Woohoo!
+    fromOss = firsts.stream()
+      .map(first -> ImmutableMap.<String, Object>builder().putAll(always).putAll(first).build())
+      .map(CapabilitiesUtils::applyTransforms)
+      .map(map -> map.entrySet().stream()
+        .filter(entry -> ACCEPTED_W3C_PATTERNS.test(entry.getKey()))
+        .collect(ImmutableMap.toImmutableMap(Map.Entry::getKey, Map.Entry::getValue)));
+
+    return fromOss;
+  }
+
+  private static Map<String, Object> convertOssToW3C(Map<String, Object> capabilities) {
+    Map<String, Object> toReturn = new TreeMap<>(capabilities);
+
+    // Platform name
+    if (capabilities.containsKey(PLATFORM) && !capabilities.containsKey(PLATFORM_NAME)) {
+      toReturn.put(PLATFORM_NAME, String.valueOf(capabilities.get(PLATFORM)));
+    }
+
+    if (capabilities.containsKey(PROXY)) {
+      Map<String, Object> proxyMap = getProxyFromCapabilities(capabilities);
+      if (proxyMap.containsKey("noProxy")) {
+        Map<String, Object> w3cProxyMap = new HashMap<>(proxyMap);
+        Object rawData = proxyMap.get("noProxy");
+        if (rawData instanceof String) {
+          w3cProxyMap.put("noProxy", Arrays.asList(((String) rawData).split(",\\s*")));
+        }
+        toReturn.put(CapabilityType.PROXY, w3cProxyMap);
+      }
+    }
+
+    return toReturn;
+  }
+
+  private static Map<String, Object> getProxyFromCapabilities(Map<String, Object> capabilities) {
+    Object rawProxy = capabilities.get(CapabilityType.PROXY);
+    if (rawProxy instanceof Proxy) {
+      return ((Proxy) rawProxy).toJson();
+    } else if (rawProxy instanceof Map) {
+      //noinspection unchecked
+      return (Map<String, Object>) rawProxy;
+    } else {
+      return new HashMap<>();
+    }
+  }
+
+  private static Map<String, Object> applyTransforms(Map<String, Object> caps) {
+    Queue<Map.Entry<String, Object>> toExamine = new LinkedList<>(caps.entrySet());
+    Set<String> seenKeys = new HashSet<>();
+    Map<String, Object> toReturn = new TreeMap<>();
+
+    Set<CapabilityTransform> transforms = getCapabilityTransforms();
+
+    // Take each entry and apply the transforms
+    while (!toExamine.isEmpty()) {
+      Map.Entry<String, Object> entry = toExamine.remove();
+      seenKeys.add(entry.getKey());
+
+      if (entry.getValue() == null) {
+        continue;
+      }
+
+      for (CapabilityTransform transform : transforms) {
+        Collection<Map.Entry<String, Object>> result = transform.apply(entry);
+        if (result == null) {
+          toReturn.remove(entry.getKey());
+          break;
+        }
+
+        for (Map.Entry<String, Object> newEntry : result) {
+          if (!seenKeys.contains(newEntry.getKey())) {
+            toExamine.add(newEntry);
+          } else {
+            if (newEntry.getKey().equals(entry.getKey())) {
+              entry = newEntry;
+            }
+            toReturn.put(newEntry.getKey(), newEntry.getValue());
+          }
+        }
+      }
+    }
+    return toReturn;
+  }
+
+  private static Set<CapabilitiesFilter> getCapabilityFilters() {
+    ImmutableSet.Builder<CapabilitiesFilter> adapters = ImmutableSet.builder();
+    ServiceLoader.load(CapabilitiesFilter.class).forEach(adapters::add);
+    adapters
+      .add(new ChromeFilter())
+      .add(new EdgeFilter())
+      .add(new FirefoxFilter())
+      .add(new InternetExplorerFilter())
+      .add(new OperaFilter())
+      .add(new SafariFilter());
+    return adapters.build();
+  }
+
+  private static Set<CapabilityTransform> getCapabilityTransforms() {
+    ImmutableSet.Builder<CapabilityTransform> transforms = ImmutableSet.builder();
+    ServiceLoader.load(CapabilityTransform.class).forEach(transforms::add);
+    transforms
+      .add(new ProxyTransform())
+      .add(new StripAnyPlatform())
+      .add(new W3CPlatformNameNormaliser());
+    return transforms.build();
+  }
+}