TracingUtil.java
/*
* Copyright (C) 2022 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 androidx.test.espresso.util;
import static com.google.common.base.Strings.nullToEmpty;
import androidx.annotation.RestrictTo;
import androidx.annotation.RestrictTo.Scope;
import com.google.common.base.Joiner;
import com.google.common.base.Strings;
import java.util.ArrayList;
import java.util.List;
/**
* Utility methods for tracing.
*
* @hide
*/
@RestrictTo(Scope.LIBRARY)
public final class TracingUtil {
private static final int SPAN_NAME_MAX_LEN = 100;
private static final String SPAN_NAME_EXCLUDE = "[^0-9A-Za-z._$()\[\] /:-]";
private TracingUtil() {}
/**
* Generates a span name according to multiple optional arguments.
*
* @param prefix User-defined prefix string, e.g. Espresso.
* @param methodName The name of method being traced, e.g. onView, perform, and check.
* @param arguments An optional list of description of arguments, e.g. user-defined description,
* ViewAction's class name, and description of Matcher.
* @return a string as the name of a span.
*/
public static String getSpanName(String prefix, String methodName, Object... arguments) {
// Sanitize all input data.
String processedPrefix = sanitizeName(prefix, SPAN_NAME_EXCLUDE, -1);
String processedMethodName = sanitizeName(methodName, SPAN_NAME_EXCLUDE, -1);
List<String> processedArguments = new ArrayList<>();
if (arguments != null) {
for (Object argument : arguments) {
if (argument == null) {
continue;
}
String processedArgument = sanitizeName(argument.toString(), SPAN_NAME_EXCLUDE, -1);
if (!processedArgument.isEmpty()) {
processedArguments.add(processedArgument);
}
}
}
// Assemble processed strings.
String spanName = processedPrefix;
if (!processedPrefix.isEmpty() && !processedMethodName.isEmpty()) {
spanName += ".";
}
spanName += processedMethodName;
if (!processedArguments.isEmpty()) {
spanName += "(" + Joiner.on(", ").join(processedArguments) + ")";
}
// Check the length.
spanName = sanitizeName(spanName, null, SPAN_NAME_MAX_LEN);
return spanName;
}
/**
* Generates a short string indicating the class type of the given element.
*
* @param element An object instance.
* @param defaultName The default result in case the class type is not accessible.
* @return a string as the class name.
*/
public static String getClassName(Object element, String defaultName) {
// Note: getSimpleName() may return an empty string for an anonymous class.
// Ideally we would use Class.getTypeName() but this is not supported in legacy
// Android with compiler < 1.8.
String name = element == null ? null : element.getClass().getSimpleName();
if (Strings.isNullOrEmpty(name)) {
name = defaultName;
}
return nullToEmpty(name);
}
/**
* Generates a span name according to multiple optional arguments.
*
* @param name The input name to be processed.
* @param exclude A regex pattern indicating the characters to exclude.
* @param maxLength The maximum length of the name; the substring out of the length will be
* deleted; skip the length check if maxLength is negative.
* @return a string as the name.
*/
private static String sanitizeName(String name, String exclude, int maxLength) {
if (name == null) {
return "";
}
String newName = name;
if (!Strings.isNullOrEmpty(exclude)) {
newName = newName.replaceAll(exclude, "").trim();
}
if (maxLength > 0 && newName.length() > maxLength) {
newName = newName.substring(0, maxLength).trim();
}
return newName;
}
}