AssistedInjectAndInjectOnConstructors
@AssistedInject and @Inject should not be used on different constructors in the same class.

Severity
WARNING
Has Fix?
NO_FIX

The problem

Mixing @Inject and @AssistedInject leads to confusing code and the documentation specifies not to do it. See https://google.github.io/guice/api-docs/latest/javadoc/com/google/inject/assistedinject/AssistedInject.html

Suppression

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


Positive examples

AssistedInjectAndInjectOnConstructorsPositiveCases.java

/*
* Copyright 2013 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.inject.testdata;

import com.google.inject.assistedinject.AssistedInject;

/** @author sgoldfeder@google.com (Steven Goldfeder) */
public class AssistedInjectAndInjectOnConstructorsPositiveCases {
/**
* Class has a constructor annotated with @javax.inject.Inject and another constructor annotated
* with @AssistedInject.
*/

// BUG: Diagnostic contains: AssistedInjectAndInjectOnConstructors
public class TestClass1 {
@javax.inject.Inject
public TestClass1() {}

@AssistedInject
public TestClass1(int n) {}
}

/**
* Class has a constructor annotated with @com.google.inject.Inject and another constructor
* annotated with @AssistedInject.
*/

// BUG: Diagnostic contains: AssistedInjectAndInjectOnConstructors
public class TestClass2 {
@com.google.inject.Inject
public TestClass2() {}

@AssistedInject
public TestClass2(int n) {}
}

/**
* Class has a constructor annotated with @com.google.inject.Inject, another constructor annotated
* with @AssistedInject, and a third constructor with no annotation.
*/

// BUG: Diagnostic contains: AssistedInjectAndInjectOnConstructors
public class TestClass3 {
@com.google.inject.Inject
public TestClass3() {}

@AssistedInject
public TestClass3(int n) {}

public TestClass3(String s) {}
}
}

Negative examples

AssistedInjectAndInjectOnConstructorsNegativeCases.java

/*
* Copyright 2013 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.inject.testdata;

import com.google.inject.assistedinject.AssistedInject;

/** @author sgoldfeder@google.com (Steven Goldfeder) */
public class AssistedInjectAndInjectOnConstructorsNegativeCases {
/** Class has a single constructor with no annotation. */
public class TestClass1 {
TestClass1() {}
}

/** Class has a constructor with a @javax.inject.Inject annotation. */
public class TestClass2 {
@javax.inject.Inject
public TestClass2() {}
}

/** Class has a constructor with a @com.google.inject.Inject annotation. */
public class TestClass3 {
@com.google.inject.Inject
public TestClass3() {}
}

/** Class has a constructor annotated with @AssistedInject */
public class TestClass4 {
@AssistedInject
public TestClass4() {}
}

/** Class has a constructor with a @AssistedInject annotation as well as an injectable field */
public class TestClass5 {
@javax.inject.Inject private int n;

@AssistedInject
public TestClass5() {}
}

/**
* Class has a constructor annotated with @javax.inject.Inject and another constructor annotated
* with @AssistedInject. The warning is suppressed.
*/

@SuppressWarnings("AssistedInjectAndInjectOnConstructors")
public class TestClass6 {
@javax.inject.Inject
public TestClass6() {}

@AssistedInject
public TestClass6(int n) {}
}
}