Skip to content

Preview/pmd #49

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.

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
wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Preview/pmd #49

wants to merge 2 commits into from

Conversation

alexcoderabbitai
Copy link

@alexcoderabbitai alexcoderabbitai commented Jul 16, 2025

image

Summary by CodeRabbit

  • New Features
    • Added a new class with a method that prints lines to the console.
    • Introduced a new ruleset for code quality enforcement, including naming conventions and code structure guidelines.

Copy link

coderabbitai bot commented Jul 16, 2025

Walkthrough

A new Java class, BadExample, is introduced with a method demonstrating several code issues, such as an unused field, an empty catch block, and a return in the finally block. Additionally, a PMD ruleset XML file is added, specifying code quality rules to detect similar issues and enforce Java coding conventions.

Changes

File(s) Change Summary
bad.java Added BadExample class with an unused private field, a constructor, and a method with code patterns targeted by static analysis.
ruleset.xml Introduced a PMD ruleset XML specifying rules for unused fields, empty catch blocks, naming conventions, and method/class length checks.

Poem

In the warren, code is new,
With rules and checks to guide us through.
A class with quirks, a ruleset bright,
To catch the bugs that hop at night.
May our carrots grow, our errors few,
PMD and bunnies—reviewing for you! 🥕

✨ Finishing Touches
  • 📝 Generate Docstrings

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

  • Review comments: Directly reply to a review comment made by CodeRabbit. Example:
    • I pushed a fix in commit <commit_id>, please review it.
    • Explain this complex logic.
    • Open a follow-up GitHub issue for this discussion.
  • Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
    • @coderabbitai explain this code block.
    • @coderabbitai modularize this function.
  • PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
    • @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
    • @coderabbitai read src/utils.ts and explain its main purpose.
    • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
    • @coderabbitai help me debug CodeRabbit configuration file.

Support

Need help? Create a ticket on our support page for assistance with any issues or questions.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (Invoked using PR comments)

  • @coderabbitai pause to pause the reviews on a PR.
  • @coderabbitai resume to resume the paused reviews.
  • @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
  • @coderabbitai full review to do a full review from scratch and review all the files again.
  • @coderabbitai summary to regenerate the summary of the PR.
  • @coderabbitai generate docstrings to generate docstrings for this PR.
  • @coderabbitai generate sequence diagram to generate a sequence diagram of the changes in this PR.
  • @coderabbitai resolve resolve all the CodeRabbit review comments.
  • @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
  • @coderabbitai help to get help.

Other keywords and placeholders

  • Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
  • Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
  • Add @coderabbitai anywhere in the PR title to generate the title automatically.

Documentation and Community

  • Visit our Documentation for detailed information on how to use CodeRabbit.
  • Join our Discord Community to get help, request features, and share feedback.
  • Follow us on X/Twitter for updates and announcements.

Copy link

@coderabbitai coderabbitai bot left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actionable comments posted: 6

🧹 Nitpick comments (1)
ruleset.xml (1)

30-33: Consider explicitly defining naming patterns.

While PMD defaults are generally good, consider adding explicit patterns for fields, methods, and classes if your team has specific conventions to ensure consistency.

Example configuration with explicit patterns:

<rule ref="category/java/codestyle.xml/FieldNamingConventions">
    <properties>
        <property name="publicConstantPattern" value="^[A-Z][A-Z0-9_]*$"/>
        <property name="constantPattern" value="^[A-Z][A-Z0-9_]*$"/>
        <property name="finalFieldPattern" value="^[a-z][a-zA-Z0-9]*$"/>
        <property name="defaultFieldPattern" value="^[a-z][a-zA-Z0-9]*$"/>
    </properties>
</rule>
📜 Review details

Configuration used: .coderabbit.yaml
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between ef04b8d and 3ec3bb6.

⛔ Files ignored due to path filters (1)
  • .coderabbit.yaml is excluded by none and included by none
📒 Files selected for processing (2)
  • bad.java (1 hunks)
  • ruleset.xml (1 hunks)
🧰 Additional context used
🪛 PMD (7.15.0)
bad.java

[Medium] 3-3: Avoid unused private fields such as 'unusedField'. (UnusedPrivateField)

(Best Practices)


[Medium] 5-5: Avoid unnecessary constructors - the compiler will generate these for you (UnnecessaryConstructor)

(Code Style)


[High] 9-9: The instance method name 'DOStuff' doesn't match '[a-z][a-zA-Z0-9]*' (MethodNamingConventions)

(Code Style)


[High] 11-11: The local variable name 'FooBar' doesn't match '^[a-z][a-zA-Z0-9]*$' (LocalVariableNamingConventions)

(Code Style)


[Medium] 17-19: Avoid empty catch blocks (EmptyCatchBlock)

(Error Prone)


[Medium] 20-20: Avoid returning from a finally block (ReturnFromFinallyBlock)

(Error Prone)

🔇 Additional comments (5)
ruleset.xml (4)

1-8: Well-structured PMD ruleset configuration!

The XML header and namespace declarations are correctly formatted for PMD 2.0.0.


9-13: Good selection of essential code quality rules.

These rules effectively catch common coding issues like unused fields, improper exception handling, and unnecessary code.


15-20: Standard Java naming convention for local variables.

The regex pattern correctly enforces camelCase starting with lowercase. Consider documenting why this specific pattern was chosen if it differs from your team's conventions.


22-28: Reasonable complexity thresholds.

The NCSS (Non-Commenting Source Statements) limits of 25 for methods and 500 for classes strike a good balance between maintainability and practicality.

bad.java (1)

1-24: Note: This appears to be an intentional example of bad code.

Given the filename and PR context, this file seems designed to demonstrate PMD rule violations. If this is indeed a test file, consider:

  1. Moving it to a test resources directory
  2. Adding a clear comment at the top indicating it's an intentional bad example
  3. Ensuring it's excluded from production code

// unnecessary constructor
}

public void DOStuff() {
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue

Follow Java naming conventions for methods.

Method names should start with a lowercase letter.

-    public void DOStuff() {
+    public void doStuff() {
🧰 Tools
🪛 PMD (7.15.0)

[High] 9-9: The instance method name 'DOStuff' doesn't match '[a-z][a-zA-Z0-9]*' (MethodNamingConventions)

(Code Style)

🤖 Prompt for AI Agents
In bad.java at line 9, the method name DOStuff does not follow Java naming
conventions which require method names to start with a lowercase letter. Rename
the method from DOStuff to doStuff to comply with the standard Java naming
conventions.

Comment on lines +5 to +7
public BadExample() {
// unnecessary constructor
}
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue

Remove unnecessary constructor.

The default constructor adds no value and can be removed.

-    public BadExample() {
-        // unnecessary constructor
-    }
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
public BadExample() {
// unnecessary constructor
}
🧰 Tools
🪛 PMD (7.15.0)

[Medium] 5-5: Avoid unnecessary constructors - the compiler will generate these for you (UnnecessaryConstructor)

(Code Style)

🤖 Prompt for AI Agents
In bad.java around lines 5 to 7, the constructor is unnecessary as it does not
add any functionality. Remove the entire constructor method to rely on the
default constructor provided by Java.


public void DOStuff() {
try {
int FooBar = 1;
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue

Follow Java naming conventions for local variables.

Local variable names should start with a lowercase letter.

-            int FooBar = 1;
+            int fooBar = 1;
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
int FooBar = 1;
int fooBar = 1;
🧰 Tools
🪛 PMD (7.15.0)

[High] 11-11: The local variable name 'FooBar' doesn't match '^[a-z][a-zA-Z0-9]*$' (LocalVariableNamingConventions)

(Code Style)

🤖 Prompt for AI Agents
In bad.java at line 11, the local variable name 'FooBar' starts with an
uppercase letter, which violates Java naming conventions. Rename the variable to
start with a lowercase letter, such as 'fooBar', to follow standard Java style
for local variables.

Comment on lines +17 to +19
} catch (Exception e) {
// silently ignored
} finally {
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue

Avoid empty catch blocks.

Empty catch blocks silently swallow exceptions, making debugging difficult. At minimum, log the exception.

         } catch (Exception e) {
-            // silently ignored
+            // Log the exception or handle it appropriately
+            e.printStackTrace(); // Or use proper logging
         } finally {
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
} catch (Exception e) {
// silently ignored
} finally {
} catch (Exception e) {
// Log the exception or handle it appropriately
e.printStackTrace(); // Or use proper logging
} finally {
🧰 Tools
🪛 PMD (7.15.0)

[Medium] 17-19: Avoid empty catch blocks (EmptyCatchBlock)

(Error Prone)

🤖 Prompt for AI Agents
In bad.java around lines 17 to 19, the catch block is empty and silently ignores
exceptions, which hinders debugging. Modify the catch block to log the caught
exception using an appropriate logging mechanism or print the stack trace to
ensure the error is recorded and can be diagnosed later.

} catch (Exception e) {
// silently ignored
} finally {
return; // forbidden in finally block
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue

Never return from a finally block.

Returning from a finally block suppresses any exceptions thrown in the try or catch blocks and can lead to unexpected behavior.

         } finally {
-            return; // forbidden in finally block
+            // Cleanup code if needed, but no return statement
         }
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
return; // forbidden in finally block
} finally {
// Cleanup code if needed, but no return statement
}
🧰 Tools
🪛 PMD (7.15.0)

[Medium] 20-20: Avoid returning from a finally block (ReturnFromFinallyBlock)

(Error Prone)

🤖 Prompt for AI Agents
In bad.java at line 20, remove the return statement from the finally block
because returning there suppresses exceptions from try or catch blocks. Instead,
restructure the code to avoid returning inside finally, such as moving the
return to the try or catch blocks or using a variable to hold the return value
and returning after the finally block completes.

@@ -0,0 +1,24 @@
public class BadExample {

private int unusedField;
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

⚠️ Potential issue

Remove unused private field.

The field unusedField is declared but never used in the class.

-    private int unusedField;
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
private int unusedField;
🧰 Tools
🪛 PMD (7.15.0)

[Medium] 3-3: Avoid unused private fields such as 'unusedField'. (UnusedPrivateField)

(Best Practices)

🤖 Prompt for AI Agents
In bad.java at line 3, there is a private field named unusedField that is
declared but never used anywhere in the class. Remove this unused private field
declaration to clean up the code and avoid unnecessary clutter.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

2 participants