Fix: Duplication Of Key 'with' In Pr-agent.yml Workflow

Encountering errors in your GitHub workflow configurations can be a real headache, especially when automated checks flag issues that aren't immediately obvious. One such issue, commonly flagged by tools like CodeFactor, is the "Duplication of key 'with' in mapping" error. This article dives into understanding this error, how to locate it within your .github/workflows/pr-agent.yml file, and provides a comprehensive guide on how to resolve it, ensuring your CI/CD pipeline runs smoothly.

Understanding the "Duplication of key 'with'" Error

When you see the "Duplication of key 'with' in mapping" error, it means that within your YAML file, specifically in the context of a GitHub Actions workflow, you've defined the with key more than once in the same mapping or block. YAML, being a human-readable data-serialization language, relies on indentation and proper structure to define relationships. Duplicate keys violate this structure, leading to parsing errors and unpredictable behavior in your workflows.

The with key in GitHub Actions is used to provide input parameters to an action. Actions are reusable units of code that automate tasks in your workflow. When configuring an action, you often need to specify input values that the action will use during its execution. The with key is the mechanism through which you pass these values.

For example, consider a simple action that uploads files to a storage service. This action might require inputs such as the path to the files, the destination bucket, and authentication credentials. These inputs would be defined under the with key, each with a corresponding value. If, for some reason, the with key is accidentally duplicated, the YAML parser will not know which set of inputs to use, resulting in the error.

YAML Structure and the Importance of Proper Syntax

YAML's structure is critically dependent on indentation. Proper indentation defines the hierarchy and relationships between different elements in the file. When the with key is duplicated, it disrupts this hierarchy and leads to ambiguity. YAML parsers typically throw an error when they encounter duplicate keys because they cannot reliably determine the intended structure.

Common Causes of Duplication

Several factors can lead to the duplication of the with key. One common cause is copy-pasting code snippets without careful review. When copying and pasting configurations from different sources, it’s easy to inadvertently include an extra with key. Another cause can be manual editing errors, where a developer accidentally adds an extra with key while modifying the workflow file.

Additionally, complex workflows with many actions and steps can become difficult to manage, increasing the likelihood of accidental duplications. It’s essential to maintain a clear and organized structure in your workflow files to minimize these errors. Using a linter or YAML validator can also help catch these issues early in the development process.

To avoid these pitfalls, always double-check your YAML files for duplicate keys, especially after making changes or integrating code from different sources. Tools like CodeFactor can automatically detect these issues, but manual review remains an important part of maintaining high-quality workflow configurations.

Locating the Issue in .github/workflows/pr-agent.yml

The error message from CodeFactor points to a specific line in your .github/workflows/pr-agent.yml file: line 37. This is your starting point. Open the file in your editor and navigate to that line. However, keep in mind that the actual duplication might not be exactly on line 37; it could be in the surrounding lines, within the same block or mapping.

Using a Code Editor for Navigation

Most code editors have line number displays that make it easy to jump to a specific line. In Visual Studio Code, for example, you can use the Go to Line/Column command (Ctrl+G or Cmd+G) to quickly navigate to line 37. Once you're there, carefully examine the code block for any instances where the with key appears more than once.

Examining the Surrounding Code

Start by looking at the indentation levels around line 37. The with key should be properly indented under the action step where it belongs. If you see another with key at the same indentation level within the same step, that's likely the culprit. Also, check for any commented-out sections that might contain a duplicate with key. Even though commented-out code is not executed, it can still trigger validation errors.

Leveraging Search Functionality

If the file is lengthy or complex, use the search functionality of your code editor (Ctrl+F or Cmd+F) to search for the word with. This will highlight all occurrences of the with key in the file. Review each instance to ensure that it is correctly placed and not duplicated within the same mapping. Pay close attention to the indentation and structure around each with key to identify any anomalies.

Using YAML Linters and Validators

To automate the process of finding errors in your YAML files, consider using a YAML linter or validator. These tools can parse your YAML file and identify syntax errors, including duplicate keys. Many online YAML validators are available, or you can install a linter as part of your development environment. These tools can save you time and effort by quickly pinpointing errors that might be difficult to spot manually.

Example Scenario

Imagine you have the following snippet in your .github/workflows/pr-agent.yml file:

      - name: Run linters
        uses: actions/run-linters@v1
        with:
          github_token: ${{ secrets.github_token }}
        with:
          eslint: true

In this example, the with key is duplicated. The correct way to define the inputs for the actions/run-linters action is to include all inputs under a single with key:

      - name: Run linters
        uses: actions/run-linters@v1
        with:
          github_token: ${{ secrets.github_token }}
          eslint: true

By carefully examining the code around line 37 and using the search and validation tools, you should be able to locate the duplicated with key and correct the structure of your YAML file.

Resolving the Duplication

Once you've located the duplicated with key, resolving the issue typically involves one of two actions: merging the duplicate entries under a single with key or removing the redundant entry altogether.

Merging Duplicate Entries

In many cases, the duplicated with keys contain different input parameters that are all intended for the same action. In such scenarios, the correct approach is to merge these entries under a single with key. This ensures that all necessary input parameters are passed to the action without causing a syntax error.

For example, if you have the following:

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
        with:
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: us-east-1

You should merge the entries like this:

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v1
        with:
          aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
          aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          aws-region: us-east-1

By consolidating all input parameters under a single with key, you ensure that the action receives all the necessary configuration information. This approach maintains the integrity of your workflow and avoids syntax errors.

Removing Redundant Entries

In some cases, the duplicated with key might be entirely redundant, meaning it doesn't provide any unique or necessary input parameters. This can happen if you accidentally copy-pasted a section of code and forgot to remove the duplicate entry. In such cases, the simplest solution is to remove the redundant with key.

For example, if you have the following:

      - name: Set up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: 16
        with:
          node-version: 16

You can simply remove one of the with keys:

      - name: Set up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: 16

Removing the redundant entry eliminates the duplication error and ensures that your workflow runs smoothly.

Ensuring Correct Indentation

After merging or removing the duplicated with key, it's crucial to ensure that the indentation is correct. YAML relies on indentation to define the structure and hierarchy of the file. Incorrect indentation can lead to parsing errors and unexpected behavior.

Make sure that the input parameters under the with key are properly indented. They should be indented one level deeper than the with key itself. This indicates that they are part of the with mapping. If the indentation is incorrect, adjust it to match the expected structure.

Validating the YAML File

After making changes to your YAML file, it's always a good practice to validate it using a YAML linter or validator. This helps you catch any syntax errors or other issues that might prevent your workflow from running correctly. There are many online YAML validators available, or you can install a linter as part of your development environment.

By following these steps, you can effectively resolve the "Duplication of key 'with' in mapping" error and ensure that your GitHub Actions workflows run smoothly and reliably.

Example Scenario and Solution

Let's consider a practical example where the with key is duplicated in a GitHub Actions workflow file. Suppose you have the following configuration in your .github/workflows/pr-agent.yml file:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3
      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.9'
      - name: Install dependencies
        run: | 
          python -m pip install --upgrade pip
          pip install -r requirements.txt
      - name: Run linters
        uses: actions/run-linters@v1
        with:
          github_token: ${{ secrets.github_token }}
        with:
          eslint: true

In this example, the with key is duplicated under the Run linters step. The first with key specifies the github_token, while the second with key specifies that ESLint should be enabled. To resolve this issue, you need to merge these entries under a single with key:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v3
      - name: Set up Python
        uses: actions/setup-python@v4
        with:
          python-version: '3.9'
      - name: Install dependencies
        run: | 
          python -m pip install --upgrade pip
          pip install -r requirements.txt
      - name: Run linters
        uses: actions/run-linters@v1
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          eslint: true

By merging the entries, you ensure that the actions/run-linters action receives both the github_token and the instruction to enable ESLint. This resolves the duplication error and allows the workflow to run correctly.

Best Practices for Avoiding YAML Errors

To minimize the occurrence of YAML errors in your GitHub Actions workflows, consider adopting the following best practices:

1. Use a YAML Linter: Integrate a YAML linter into your development workflow. Linters can automatically detect syntax errors, indentation issues, and other common problems in your YAML files. This helps you catch errors early in the development process, before they cause issues in your CI/CD pipeline.
2. Validate Your YAML Files: Before committing changes to your workflow files, validate them using a YAML validator. There are many online YAML validators available, or you can install a validator as part of your development environment. Validating your YAML files ensures that they are syntactically correct and conform to the YAML specification.
3. Maintain a Consistent Indentation Style: YAML relies on indentation to define the structure and hierarchy of the file. Choose a consistent indentation style (e.g., two spaces or four spaces) and stick to it throughout your workflow files. This makes it easier to read and understand the structure of your YAML files and reduces the likelihood of indentation errors.
4. Use Code Snippets and Templates: To avoid repetitive typing and reduce the risk of errors, use code snippets and templates for common workflow configurations. This allows you to quickly insert pre-defined code blocks into your YAML files without having to manually type them out each time.
5. Review Changes Carefully: Before committing changes to your workflow files, review them carefully to ensure that they are correct and do not contain any errors. Pay close attention to indentation, syntax, and the placement of keys and values. It's often helpful to have another developer review your changes as well.
6. Keep Your Workflow Files Organized: Organize your workflow files in a logical and structured manner. Use comments to explain the purpose of different sections of the file and to provide context for complex configurations. This makes it easier to maintain and troubleshoot your workflow files over time.

By following these best practices, you can significantly reduce the occurrence of YAML errors in your GitHub Actions workflows and ensure that your CI/CD pipeline runs smoothly and reliably.

In conclusion, resolving the "Duplication of key 'with' in mapping" error in your .github/workflows/pr-agent.yml file involves careful examination of the code around the reported line, merging or removing duplicate entries, ensuring correct indentation, and validating the YAML file. By understanding the causes of this error and following the steps outlined in this article, you can effectively troubleshoot and resolve it, ensuring the smooth operation of your GitHub Actions workflows. For more information on YAML syntax and best practices, visit the YAML Official Website.