Catalyst – Run on Save

Execute commands automatically on file save in Visual Studio Code.

Catalyst enables you to automate development workflows by executing shell commands instantly whenever specific files are saved. Whether you need to apply formatters, linters, code generators, tests, or build tasks, this extension handles it seamlessly in the background.

Examples

1. Code Formatting with Prettier

Automatically format TypeScript, JavaScript, and JSON files on save:

{
  "catalyst-run-on-save.actions": [
    {
      "name": "Prettier Format",
      "command": "npx prettier --write \"${file}\"",
      "include": ["**/*.ts", "**/*.js", "**/*.json"],
      "exclude": ["**/node_modules/**"]
    }
  ]
}

2. Code Linting with ESLint

Automatically fix linting issues in TypeScript and JavaScript files on save:

{
  "catalyst-run-on-save.actions": [
    {
      "name": "ESLint Fix",
      "command": "npx eslint --fix \"${file}\"",
      "include": ["**/*.ts", "**/*.js"],
      "exclude": ["**/node_modules/**"]
    }
  ]
}

3. Java & Kotlin Formatting with Spotless (Gradle)

Run different Gradle scripts based on the active operating system to format Java and Kotlin files:

{
  "catalyst-run-on-save.actions": [
    {
      "name": "Spotless Format (Gradle)",
      "command": {
        "windows": "${workspaceFolder}\\gradlew.bat spotlessApply -PspotlessFiles=\"${file}\"",
        "default": "${workspaceFolder}/gradlew spotlessApply -PspotlessFiles=\"${file}\""
      },
      "include": ["**/*.java", "**/*.kt"],
      "exclude": ["**/build/**"]
    }
  ]
}

4. Go Build & Test on Save

Automatically compile and run tests in a Go project when code changes:

{
  "catalyst-run-on-save.actions": [
    {
      "name": "Build & Test Go Project",
      "command": "go build ./... && go test ./...",
      "include": ["**/*.go"],
      "exclude": ["**/vendor/**"]
    }
  ]
}

Configuration

Configure the extension inside your VS Code settings.json file.

Settings

Action Properties

Each action object in catalyst-run-on-save.actions supports the following properties:

Note: Globs are evaluated relative to your workspace root directory. They support both standard file extension patterns (e.g., **/*.ts) and directory-specific exclusions.

Variable Substitution

You can embed the following placeholders in your command strings:

Troubleshooting

Silent Failures

Problem: Commands are not running or are failing silently, making it difficult to debug the issue.

Solution: Check the extension logs in VS Code:

1. Open the Output panel in VS Code (View > Output or Cmd+Shift+U/Ctrl+Shift+U).
2. Select Catalyst from the dropdown menu in the top-right corner.
3. Review the execution logs to inspect target file matches, resolved command strings, and shell exit codes.

Spaces in File Paths

Problem: If your file paths contain spaces or special characters, commands might fail or parse incorrectly.

Solution: Always wrap ${file} and other path variables in double quotes within your command template, for example: npx prettier --write "${file}".

Command Not Found or Missing PATH Variables

Problem: VS Code commands run in a non-interactive shell environment that might not load all of your user profile configurations (like custom alias settings or dynamic PATH expansions from .bashrc or .zshrc), causing commands to fail because they cannot be found.

Solution:

• Use absolute paths for commands (e.g., /usr/local/bin/node instead of just node) if they cannot be found.
• Specify a custom shell executable using the shell option (e.g., /bin/zsh or powershell.exe) if you need a specific shell context.

Performance & High CPU Usage

Problem: Running heavy build or compile commands on every save can slow down your workspace and consume high CPU resources.

Solution: Use the exclude property to ignore files in temporary directories (e.g., **/tmp/**), build folders (e.g., **/dist/**, **/build/**), or dependency folders (e.g., **/node_modules/**).

deep.rent