PreconditionsInvalidPlaceholder
Preconditions only accepts the %s placeholder in error message strings

Category
Severity
WARNING
Maturity

The problem

The Guava Preconditions checks take error message template strings that look similar to format strings but only accept %s as a placeholder. This check points out places where there is a non-%s placeholder in a Preconditions error message template string and the number of arguments does not match the number of %s placeholders.

Suppression

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


Positive examples

PreconditionsInvalidPlaceholderPositiveCase1.java

/*
* Copyright 2012 Google Inc. All Rights Reserved.
*
* 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.base.Preconditions.checkArgument;

import com.google.common.base.Preconditions;

public class PreconditionsInvalidPlaceholderPositiveCase1 {
int foo;

public void checkPositive(int x) {
// BUG: Diagnostic contains: %s > 0
checkArgument(x > 0, "%d > 0", x);
}

public void checkFoo() {
// BUG: Diagnostic contains: foo must be equal to 0 but was %s
Preconditions.checkState(foo == 0, "foo must be equal to 0 but was {0}", foo);
}
}

Negative examples

PreconditionsInvalidPlaceholderNegativeCase1.java

/*
* Copyright 2012 Google Inc. All Rights Reserved.
*
* 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.base.Preconditions.checkArgument;

import com.google.common.base.Preconditions;

public class PreconditionsInvalidPlaceholderNegativeCase1 {
Integer foo;

public void checkPositive(int x) {
checkArgument(x > 0, "%s > 0", x);
}

public void checkTooFewArgs(int x) {
checkArgument(x > 0, "%s %s", x);
}

public void checkFoo() {
Preconditions.checkState(foo.intValue() == 0, "foo must be equal to 0 but was %s", foo);
}

public static void checkNotNull(Object foo, String bar, Object baz) {}

public void checkSelf() {
checkNotNull(foo, "Foo", this);
}
}