Github, generate report for MagicNumber/Example1

Failed to download or process the specified configuration(s).
Error details:

Please ensure you've used one of the following commands correctly:

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  And check that all specified configs or files exist and are valid.
  
  Link: https://github.com/checkstyle/checkstyle/actions/runs/11982785745

Github, generate report for MagicNumber/Example1

Report for MagicNumber/Example1:
https://checkstyle-diff-reports.s3.us-east-2.amazonaws.com/2cad2ada63b12f7151ee812317c057227694c7e2_2024024306/reports/diff/index.html

@mahfouz72, please try to trigger report one more time, not clear why your execution failed.

Github, generate report for MagicNumber/Example1

Report for MagicNumber/Example1:
https://checkstyle-diff-reports.s3.us-east-2.amazonaws.com/2cad2ada63b12f7151ee812317c057227694c7e2_2024105158/reports/diff/index.html

https://checkstyle-diff-reports.s3.us-east-2.amazonaws.com/2cad2ada63b12f7151ee812317c057227694c7e2_2024105158/reports/diff/Vavr/index.html#A1

@Test
public void shouldCheckHashCodeInLeafList() {
    HashArrayMappedTrie<Integer, Integer> trie = empty();
    trie = trie.put(0, 1).put(null, 2);  // LeafList.hash == 0
    final Option<Integer> none = trie.get(1 << 6);  // (key.hash & BUCKET_BITS) == 0
    assertThat(none).isEqualTo(Option.none());
}

I am not sure that removal of this violation is good. but in the same time if there would be * instead of <<, there will be no violation, so making << so special is not very good.

https://checkstyle-diff-reports.s3.us-east-2.amazonaws.com/2cad2ada63b12f7151ee812317c057227694c7e2_2024105158/reports/diff/spring-framework/index.html#A1

/**
 * Base kind of the base reference types. The BASE_VALUE of such types is an
 * index into the type table.
 */
static final int OBJECT = BASE | 0x700000;

kind of magic number, but it is field, so should be ignored if ignoreFieldDeclaration=true, but this report is for default config, so it is false.

https://checkstyle-diff-reports.s3.us-east-2.amazonaws.com/2cad2ada63b12f7151ee812317c057227694c7e2_2024105158/reports/diff/spring-framework/xref/home/runner/work/checkstyle/checkstyle/.ci-temp/repositories/spring-framework/spring-core/src/main/java/org/springframework/asm/Type.java.html#L104

/**
 * The <tt>void</tt> type.
 */
public static final Type VOID_TYPE = new Type(VOID, null, ('V' << 24)
        | (5 << 16) | (0 << 8) | 0, 1);

it will be kind of impossible to persuade users to put all this numbers in separate variables/constants, as 5 in one expression and in another expression can means different. And naming all digits is too much.

kind of magic number, but it is field, so should be ignored if ignoreFieldDeclaration=true, but this report is for default config,

This is ignored because the field is constant, the same as we ignore / (BASE / 5, for example), so | has nothing special to be a violation.

I agree with extending the allow list to make the check less strict. Users can still customize the list if needed.

please let me know your final decision.

Can we suggest user in issue a workaround by setting of this property with required tokens?

Do you know what other operators are not this waiver?

There are a bunch of other operators that are not on the list such as mod operation, comparison operators, and conditional operators

Example:

D:\CS\test
cat src/Test.java
public class Test {

    public static final boolean BIT6 = 1 >= 3; // violation
    public static final boolean BIT7 = 1 != 3; // violation
    public static final int BIT8 = 1 % 3; // violation
    public static final int BIT9 = 1 > 2 ? 6 : 5; // 2 violations
}
D:\CS\test
java  -jar checkstyle-10.17.0-all.jar -c config.xml src/Test.java
Starting audit...
[ERROR] D:\CS\test\src\Test.java:3:45: '3' is a magic number. [MagicNumber]
[ERROR] D:\CS\test\src\Test.java:4:45: '3' is a magic number. [MagicNumber]
[ERROR] D:\CS\test\src\Test.java:5:40: '3' is a magic number. [MagicNumber]
[ERROR] D:\CS\test\src\Test.java:6:44: '6' is a magic number. [MagicNumber]
[ERROR] D:\CS\test\src\Test.java:6:48: '5' is a magic number. [MagicNumber]
Audit done.
Checkstyle ends with 5 errors.

I just try to formulate some reasons of this property and tokens presence in it.
To make it clear what is default and what users should do themselves.

I still can't formulate reasons why we add some operators and not others. I don't think of any use case when we could violate magic numbers with one operator but not others.

The thing here is consistency. If one operator triggers a magic number violation, why should others (like addition or subtraction) not? Can we say that some operators (like arithmetic ones) are more commonly used with numbers That is why we added them in default list but others are not commonly used so we leave the option for users to add them to the list.

We can make any rule we think is reasonable. Let's drop few ideas/reasons and choose by vote what is more clear to active maintainers.

I did big post at #15950 (comment) to investigate problem.

We can make any rule we think is reasonable. Let's drop few ideas/reasons and choose by vote what is more clear to active maintainers.

moved to #15985

@mahfouz72 , see #15957 (comment)