Added a new class DeviceFeatureFlag to parse device config flag strings.

Bug: b/299973599

Test: m tradefed-all &&
./tools/tradefederation/core/javatests/run_tradefed_tests.sh --class
com.android.tradefed.targetprep.FeatureFlagTargetPreparerTest
m tradefed-all &&
./tools/tradefederation/core/javatests/run_tradefed_tests.sh --class
com.android.tradefed.util.flag.DeviceFeatureFlagTest

Change-Id: If2e829dfe254ce36165bf8b37cc544814f701891

3 files changed, 142 insertions, 14 deletions

diff --git a/javatests/com/android/tradefed/util/flag/DeviceFeatureFlagTest.java b/javatests/com/android/tradefed/util/flag/DeviceFeatureFlagTest.java
new file mode 100644
index 000000000..9b888dca9
--- /dev/null
+++ b/javatests/com/android/tradefed/util/flag/DeviceFeatureFlagTest.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * 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.android.tradefed.util.flag;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link DeviceFeatureFlag}. */
+@RunWith(JUnit4.class)
+public class DeviceFeatureFlagTest {
+    private static final String VALID_FLAG = "namespace/package.flag=value";
+    private static final String INVALID_FLAG = "invalid flag";
+
+    @Test
+    public void testConstructor_validFlag_setsFlagAttributes() {
+        DeviceFeatureFlag deviceFeatureFlag = new DeviceFeatureFlag(VALID_FLAG);
+        assertEquals("namespace", deviceFeatureFlag.getNamespace());
+        assertEquals("package.flag", deviceFeatureFlag.getFlagName());
+        assertEquals("value", deviceFeatureFlag.getFlagValue());
+    }
+
+    @Test
+    public void testConstructor_invalidFlag_throwsException() {
+        assertThrows(IllegalArgumentException.class, () -> new DeviceFeatureFlag(INVALID_FLAG));
+    }
+}
diff --git a/src/com/android/tradefed/util/flag/DeviceFeatureFlag.java b/src/com/android/tradefed/util/flag/DeviceFeatureFlag.java
new file mode 100644
index 000000000..adf54b858
--- /dev/null
+++ b/src/com/android/tradefed/util/flag/DeviceFeatureFlag.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * 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.android.tradefed.util.flag;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class DeviceFeatureFlag {
+
+    // Expected flag format (same as output by "device_config list"):
+    // namespace/name=[value]
+    // Note value is optional.
+    private static final Pattern FLAG_PATTERN =
+            Pattern.compile("^(?<namespace>[^\\s/=]+)/(?<name>[^\\s/=]+)=(?<value>.*)$");
+
+    private final String namespace;
+    private final String flagName;
+    private final String flagValue;
+
+    /**
+     * Constructor to create a new DeviceFeatureFlag object.
+     *
+     * @param flagString A device config flag string in the format of "namespace/flagName=flagValue"
+     * @throws IllegalArgumentException if the flagString parameter cannot be parsed
+     */
+    public DeviceFeatureFlag(String flagString) {
+        Matcher match = FLAG_PATTERN.matcher(flagString);
+        if (!match.matches()) {
+            throw new IllegalArgumentException(
+                    String.format("Failed to parse flag data: %s", flagString));
+        }
+        namespace = match.group("namespace");
+        flagName = match.group("name");
+        flagValue = match.group("value");
+    }
+
+    /**
+     * Get the namespace of the DeviceFeatureFlag. E.g. "namespace" in flag string
+     * "namespace/flagName=flagValue".
+     *
+     * @return namespace string
+     */
+    public String getNamespace() {
+        return namespace;
+    }
+
+    /**
+     * Get the flag name of the DeviceFeatureFlag. E.g. "flagName" in flag string
+     * "namespace/flagName=flagValue".
+     *
+     * @return flag name string
+     */
+    public String getFlagName() {
+        return flagName;
+    }
+
+    /**
+     * Get the flag value of the DeviceFeatureFlag. E.g. "flagValue" in flag string
+     * "namespace/flagName=flagValue".
+     *
+     * @return flag value string
+     */
+    public String getFlagValue() {
+        return flagValue;
+    }
+
+    /**
+     * Convert the DeviceFeatureFlag object to a flag string in the format of
+     * "namespace/flagName=flagValue"
+     *
+     * @return formatted flag string
+     */
+    @Override
+    public String toString() {
+        return String.format("%s/%s=%s", namespace, flagName, flagValue);
+    }
+}
diff --git a/test_framework/com/android/tradefed/targetprep/FeatureFlagTargetPreparer.java b/test_framework/com/android/tradefed/targetprep/FeatureFlagTargetPreparer.java
index 71323517f..338200c56 100644
--- a/test_framework/com/android/tradefed/targetprep/FeatureFlagTargetPreparer.java
+++ b/test_framework/com/android/tradefed/targetprep/FeatureFlagTargetPreparer.java
@@ -17,6 +17,7 @@ package com.android.tradefed.targetprep;
 
 import com.android.tradefed.config.Option;
 import com.android.tradefed.config.OptionClass;
+import com.android.tradefed.util.flag.DeviceFeatureFlag;
 import com.android.tradefed.device.DeviceNotAvailableException;
 import com.android.tradefed.device.ITestDevice;
 import com.android.tradefed.invoker.TestInformation;
@@ -39,8 +40,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 /**
@@ -68,12 +67,6 @@ import java.util.stream.Collectors;
 @OptionClass(alias = "feature-flags")
 public class FeatureFlagTargetPreparer extends BaseTargetPreparer {
 
-    // Expected flag format (same as output by "device_config list"):
-    // namespace/name=[value]
-    // Note value is optional.
-    private static final Pattern FLAG_PATTERN =
-            Pattern.compile("^(?<namespace>[^\\s/=]+)/(?<name>[^\\s/=]+)=(?<value>.*)$");
-
     @Option(
             name = "flag-file",
             description = "File containing flag values to apply. Can be repeated.")
@@ -201,21 +194,21 @@ public class FeatureFlagTargetPreparer extends BaseTargetPreparer {
             throws TargetSetupError {
         Map<String, Map<String, String>> flags = new HashMap<>();
         for (String line : lines) {
-            Matcher match = FLAG_PATTERN.matcher(line);
-            if (!match.matches()) {
+            try {
+                DeviceFeatureFlag deviceFeatureFlag = new DeviceFeatureFlag(line);
+                flags.computeIfAbsent(deviceFeatureFlag.getNamespace(), ns -> new HashMap<>())
+                        .put(deviceFeatureFlag.getFlagName(), deviceFeatureFlag.getFlagValue());
+            } catch (IllegalArgumentException e) {
                 if (throwIfInvalid) {
                     throw new TargetSetupError(
                             String.format("Failed to parse flag data: %s", line),
+                            e,
                             device.getDeviceDescriptor(),
                             InfraErrorIdentifier.OPTION_CONFIGURATION_ERROR);
                 }
                 CLog.w("Skipping invalid flag data: %s", line);
                 continue;
             }
-            String namespace = match.group("namespace");
-            String name = match.group("name");
-            String value = match.group("value");
-            flags.computeIfAbsent(namespace, ns -> new HashMap<>()).put(name, value);
         }
         return flags;
     }