Label extractor question

[Topi99]

Hi! I am experimenting with this action, but I'm having troubles while extracting the labels from my PR titles. I have the following naming convention: <type>: <title>. Some examples: feat: Add new button to menu, fix: Remove line causing bug. What could be the right pattern for my case?

Here is my current configuration:

{
  "categories": [
    {
      "title": "## 🚀 New Features",
      "labels": ["feat"]
    },
    {
      "title": "## 🐛 Fixes",
      "labels": ["fix"]
    },
    {
      "title": "## 🧪 Tests",
      "labels": ["test"]
    },
    {
        "title": "## 📦 Dependencies",
        "labels": ["deps"]
    },
    {
      "title": "## 📖 Documentation",
      "labels": ["docs"]
    },
    {
      "title": "## 🧹 Chores",
      "labels": ["chore"]
    }
  ],
  "ignore_labels": [
    "ignore"
  ],
  "sort": "ASC",
  "template": "${{CHANGELOG}}\n\n<details>\n<summary>Uncategorized</summary>\n\n${{UNCATEGORIZED}}\n</details>",
  "pr_template": "- ${{TITLE}}\n   - PR: #${{NUMBER}} labels: ${{LABELS}}",
  "empty_template": "- no changes",
  "label_extractor": [
    {
      "pattern": "^feat",
      "target": "feat",
      "on_property": "title"
    },
    {
      "pattern": "^test",
      "target": "test",
      "on_property": "title"
    },
    {
      "pattern": "^build",
      "target": "deps",
      "on_property": "title"
    },
    {
      "pattern": "^fix",
      "target": "fix",
      "on_property": "title"
    },
    {
      "pattern": "^docs",
      "target": "docs",
      "on_property": "title"
    },
    {
      "pattern": "^doc",
      "target": "docs",
      "on_property": "title"
    },
    {
      "pattern": "^chore",
      "target": "chore",
      "on_property": "title"
    }
  ]
}

I have tried several patterns but none seems to work (I'm new with regex).

Thanks in advance.

[mikepenz]

@Topi99 you were already very close to the solution.

There are 2 variants the action offers the extractor to be used. One is replace and the other is match.
By default replace is used:

https://github.com/mikepenz/release-changelog-builder-action/blob/develop/src/transform.ts#L351-L361

Replace uses the title and replaces the section matched by the regex with the target.

In your case you want to use match instead though, which doesn't need a target and instead extracts the label from the title. ( It does: onValue.match(extractor.pattern))

So to solve your setup you want to adjust the transformers to:

{
      "pattern": "^feat",
      "on_property": "title"
      "method": "match"
}

Created also a sample testcase for you to quickly try things out:
https://github.com/mikepenz/release-changelog-builder-action/tree/feature/607_test

Checkout this branch, and after having done the normal node setup, you can run the test case via:

npm test -- extractor.test.ts

[Topi99]

Thank you @mikepenz, it is working now. I also ran the tests and it is looking good. Now I am going to work on my transformers so I can get rid of the type of the PRs in the change log.