com.google.common.truth.FailureContext Maven / Gradle / Ivy
/*
* Copyright (c) 2016 Google, Inc.
*
* 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.common.truth;
import static com.google.common.base.Preconditions.checkArgument;
import javax.annotation.Nullable;
/**
* An abstract type which holds a context message and formats it on demand.
*
* {@code FailureMessageHolder} is a parent to those Verb types which will need to be modified
* with failure message state.
*/
// TODO(cgruber) Extract supplementary message state from the Verb hierarchy entirely.
// Requres lots of client fixes.
public class FailureContext {
private static final String PLACEHOLDER_ERR =
"Incorrect number of args (%s) for the given placeholders (%s) in string template:\"%s\"";
private final String format;
private final Object[] args;
public FailureContext(@Nullable String format, @Nullable Object... args) {
this.format = format;
this.args = args;
int placeholders = countPlaceholders(format);
checkArgument(placeholders == args.length, PLACEHOLDER_ERR, args.length, placeholders, format);
}
@Nullable
protected String getFailureMessage() {
return hasFailureMessage() ? StringUtil.format(format, args) : null;
}
protected boolean hasFailureMessage() {
return format != null;
}
static int countPlaceholders(@Nullable String template) {
if (template == null) {
return 0;
}
int index = 0;
int count = 0;
while (true) {
index = template.indexOf("%s", index);
if (index == -1) {
break;
}
index++;
count++;
}
return count;
}
}