ShouldHaveEvenArgs
This method must be called with an even number of arguments.

Severity
ERROR
Has Fix?
NO_FIX

The problem

Suppression

Suppress false positives by adding the suppression annotation @SuppressWarnings("ShouldHaveEvenArgs") to the enclosing element.


Positive examples

ShouldHaveEvenArgsPositiveCases.java

/*
* Copyright 2017 The Error Prone Authors.
*
* 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.errorprone.bugpatterns.testdata;

import static com.google.common.truth.Truth.assertThat;

import com.google.common.truth.Correspondence;
import java.util.HashMap;
import java.util.Map;

/**
* Positive test cases for {@link ShouldHaveEvenArgs} check.
*
* @author bhagwani@google.com (Sumit Bhagwani)
*/

public class ShouldHaveEvenArgsPositiveCases {

private static final Map map = new HashMap<String, String>();

public void testWithOddArgs() {
// BUG: Diagnostic contains: even number of arguments
assertThat(map).containsExactly("hello", "there", "rest");

// BUG: Diagnostic contains: even number of arguments
assertThat(map).containsExactly("hello", "there", "hello", "there", "rest");

// BUG: Diagnostic contains: even number of arguments
assertThat(map).containsExactly(null, null, null, null, new Object[] {});
}

public void testWithArrayArgs() {
String key = "hello";
Object[] value = new Object[] {};
Object[][] args = new Object[][] {};

// BUG: Diagnostic contains: even number of arguments
assertThat(map).containsExactly(key, value, (Object) args);
}

public void testWithOddArgsWithCorrespondence() {
assertThat(map)
.comparingValuesUsing(new TestCorrespondence())
// BUG: Diagnostic contains: even number of arguments
.containsExactly("hello", "there", "rest");

assertThat(map)
.comparingValuesUsing(new TestCorrespondence())
// BUG: Diagnostic contains: even number of arguments
.containsExactly("hello", "there", "hello", "there", "rest");
}

private static class TestCorrespondence extends Correspondence<String, String> {

@Override
public boolean compare(String str1, String str2) {
return true;
}

@Override
public String toString() {
return "test_correspondence";
}
}
}

Negative examples

ShouldHaveEvenArgsNegativeCases.java

/*
* Copyright 2017 The Error Prone Authors.
*
* 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.errorprone.bugpatterns.testdata;

import static com.google.common.truth.Truth.assertThat;

import java.util.HashMap;
import java.util.Map;

/**
* Negative test cases for {@link ShouldHaveEvenArgs} check.
*
* @author bhagwani@google.com (Sumit Bhagwani)
*/

public class ShouldHaveEvenArgsNegativeCases {

private static final Map<String, String> map = new HashMap<String, String>();

public void testWithNoArgs() {
assertThat(map).containsExactly();
}

public void testWithMinimalArgs() {
assertThat(map).containsExactly("hello", "there");
}

public void testWithEvenArgs() {
assertThat(map).containsExactly("hello", "there", "hello", "there");
}

public void testWithVarargs(Object... args) {
assertThat(map).containsExactly("hello", args);
assertThat(map).containsExactly("hello", "world", args);
}

public void testWithArray() {
String[] arg = {"hello", "there"};
assertThat(map).containsExactly("yolo", arg);

String key = "hello";
Object[] value = new Object[] {};
Object[][] args = new Object[][] {};

assertThat(map).containsExactly(key, value);
assertThat(map).containsExactly(key, value, (Object[]) args);
assertThat(map).containsExactly(key, value, key, value, key, value);
}
}