Skip to content

Handle negation and formatting in ObjectEqualsForPrimitives #6038

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
copybara-service wants to merge 1 commit into
base: master
Choose a base branch
from
+185 −9
Open

Handle negation and formatting in ObjectEqualsForPrimitives #6038

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
74 changes: 72 additions & 2 deletions core/src/main/java/com/google/errorprone/bugpatterns/ObjectEqualsForPrimitives.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,9 +30,18 @@
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.util.ASTHelpers;
import com.google.errorprone.util.OperatorPrecedence;
import com.sun.source.tree.AssignmentTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.NewClassTree;
import com.sun.source.tree.ParenthesizedTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.Tree.Kind;
import com.sun.source.tree.VariableTree;
import com.sun.source.util.TreePath;
import com.sun.tools.javac.code.Type;
import java.util.Objects;
import javax.lang.model.type.TypeKind;

/**
Expand Down Expand Up @@ -71,11 +80,72 @@ public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState
String arg1 = state.getSourceForNode(expression1);
String arg2 = state.getSourceForNode(expression2);

// TODO: Rewrite to a != b if the original code has a negation (e.g. !Object.equals)
Fix fix = SuggestedFix.builder().replace(tree, "(" + arg1 + " == " + arg2 + ")").build();
TreePath parentPath = state.getPath().getParentPath();
while (parentPath != null && parentPath.getLeaf() instanceof ParenthesizedTree) {
parentPath = parentPath.getParentPath();
}
if (parentPath != null && parentPath.getLeaf().getKind() == Kind.LOGICAL_COMPLEMENT) {
Tree target = parentPath.getLeaf();
String replacement =
String.format(requiresParentheses(parentPath) ? "(%s != %s)" : "%s != %s", arg1, arg2);
Fix fix = SuggestedFix.builder().replace(target, replacement).build();
return describeMatch(target, fix);
}

String replacement =
String.format(requiresParentheses(state.getPath()) ? "(%s == %s)" : "%s == %s", arg1, arg2);
Fix fix = SuggestedFix.builder().replace(tree, replacement).build();
return describeMatch(tree, fix);
}

private static boolean requiresParentheses(TreePath path) {
TreePath parentPath = path.getParentPath();
if (parentPath == null) {
return false;
}
Tree parent = parentPath.getLeaf();
switch (parent.getKind()) {
case PARENTHESIZED,
RETURN,
EXPRESSION_STATEMENT,
ARRAY_ACCESS,
ASSERT,
LAMBDA_EXPRESSION,
CONDITIONAL_EXPRESSION -> {
return false;
}
case VARIABLE -> {
if (Objects.equals(((VariableTree) parent).getInitializer(), path.getLeaf())) {
return false;
}
}
case ASSIGNMENT -> {
if (Objects.equals(((AssignmentTree) parent).getExpression(), path.getLeaf())) {
return false;
}
}
case METHOD_INVOCATION -> {
if (((MethodInvocationTree) parent).getArguments().contains(path.getLeaf())) {
return false;
}
}
case NEW_CLASS -> {
if (((NewClassTree) parent).getArguments().contains(path.getLeaf())) {
return false;
}
}
case AND, XOR, OR, EQUAL_TO, NOT_EQUAL_TO -> {
return true;
}
default -> {
return OperatorPrecedence.optionallyFrom(parent.getKind())
.map(p -> p.isHigher(OperatorPrecedence.EQUALITY))
.orElse(false);
}
}
return true;
}

private static boolean isFloatingPoint(ExpressionTree expression) {
Type type = ASTHelpers.getType(expression);
if (type == null) {
Expand Down
120 changes: 113 additions & 7 deletions core/src/test/java/com/google/errorprone/bugpatterns/ObjectEqualsForPrimitivesTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -131,15 +131,15 @@ private static boolean testLongs(long a, long b) {

public class Test {
private static boolean testBooleans(boolean a, boolean b) {
return (a == b);
return a == b;
}

private static boolean testInts(int a, int b) {
return (a == b);
return a == b;
}

private static boolean testLongs(long a, long b) {
return (a == b);
return a == b;
}
}
""")
Expand Down Expand Up @@ -175,15 +175,121 @@ private static boolean testLongs(long a, long b) {

public class Test {
private static boolean testBooleans(boolean a, boolean b) {
return !(a == b);
return a != b;
}

private static boolean testInts(int a, int b) {
return !(a == b);
return a != b;
}

private static boolean testLongs(long a, long b) {
return !(a == b);
return a != b;
}
}
""")
.doTest();
}

@Test
public void primitivesNegatedWithParentheses() {
refactoringHelper
.addInputLines(
"Test.java",
"""
import java.util.Objects;

public class Test {
private static boolean testBooleans(boolean a, boolean b) {
return !(Objects.equals(a, b));
}

private static boolean testInts(int a, int b) {
return !((Objects.equals(a, b)));
}
}
""")
.addOutputLines(
"Test.java",
"""
import java.util.Objects;

public class Test {
private static boolean testBooleans(boolean a, boolean b) {
return a != b;
}

private static boolean testInts(int a, int b) {
return a != b;
}
}
""")
.doTest();
}

@Test
public void requiresParenthesesContexts() {
refactoringHelper
.addInputLines(
"Test.java",
"""
import java.util.Objects;

public class Test {
private static String concat(int a, int b) {
return "res: " + Objects.equals(a, b);
}

private static String concatNegated(int a, int b) {
return "res: " + !Objects.equals(a, b);
}

private static Object cast(int a, int b) {
return (Object) Objects.equals(a, b);
}

private static boolean bitwise(int a, int b, boolean c) {
return Objects.equals(a, b) & c;
}

private static boolean logical(int a, int b, boolean c) {
return Objects.equals(a, b) && c;
}

private static void ifCondition(int a, int b) {
if (Objects.equals(a, b)) {}
if (!Objects.equals(a, b)) {}
}
}
""")
.addOutputLines(
"Test.java",
"""
import java.util.Objects;

public class Test {
private static String concat(int a, int b) {
return "res: " + (a == b);
}

private static String concatNegated(int a, int b) {
return "res: " + (a != b);
}

private static Object cast(int a, int b) {
return (Object) (a == b);
}

private static boolean bitwise(int a, int b, boolean c) {
return (a == b) & c;
}

private static boolean logical(int a, int b, boolean c) {
return a == b && c;
}

private static void ifCondition(int a, int b) {
if (a == b) {}
if (a != b) {}
}
}
""")
Expand Down Expand Up @@ -211,7 +317,7 @@ private static boolean doTest(int a, long b) {

public class Test {
private static boolean doTest(int a, long b) {
return (a == b);
return a == b;
}
}
""")
Expand Down
Loading