### Install Widdershins CLI

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicCLI.html

Install the Widdershins package globally using NPM to enable command-line access.

```bash
npm install -g widdershins
```

--------------------------------

### Configure Widdershins Options

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

Set up an options object to customize Widdershins' behavior. Use the JavaScript parameter names as specified in the README.md file. This example configures language tabs for code samples.

```javascript
const options = {
  language_tabs: [{ python: "Python" }, { ruby: "Ruby" }]
};

```

--------------------------------

### Install Widdershins with NPM

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

Add Widdershins as a project dependency using NPM. This command should be run from the root folder of your project, which contains the package.json file.

```bash
npm install --save widdershins

```

--------------------------------

### Convert OpenAPI File via CLI

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicCLI.html

Execute the conversion process by specifying an environment configuration file, the input definition, and the output filename.

```bash
widdershins --environment env.json swagger.json -o myOutput.md
```

--------------------------------

### Configure Widdershins Environment

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicCLI.html

Define conversion options in a JSON file to reuse settings across multiple runs.

```json
{
"language_tabs": [{ "python": "Python" }, { "ruby": "Ruby" }]
}
```

--------------------------------

### Run JavaScript Conversion Program

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

Execute the created JavaScript file using NodeJS to perform the conversion from an OpenAPI/Swagger file to Markdown. This command assumes your JavaScript file is named 'convertMarkdown.js'.

```bash
node convertMarkdown.js

```

--------------------------------

### Complete JavaScript Program for Markdown Conversion

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

This is a complete JavaScript program that imports Widdershins, reads a swagger.json file, converts it to Markdown with specified options, and writes the output to myOutput.md. It includes error handling for the conversion process.

```javascript
const widdershins = require('widdershins');
const fs = require('fs');

const options = {
  language_tabs: [{ python: "Python" }, { ruby: "Ruby" }]
};

const fileData = fs.readFileSync('swagger.json', 'utf8');
const swaggerFile = JSON.parse(fileData);

widdershins.convert(swaggerFile, options)
.then(markdownOutput => {
  // markdownOutput contains the converted markdown
  fs.writeFileSync('myOutput.md', markdownOutput, 'utf8');
})
.catch(err => {
  // handle errors
});

```

--------------------------------

### Convert OpenAPI/Swagger to Markdown with Promise

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

Utilize the Widdershins convert function, which returns a Promise, to transform the parsed API definition into Markdown. Handle potential errors using .catch().

```javascript
widdershins.convert(swaggerFile, options)
.then(markdownOutput => {
  // markdownOutput contains the converted markdown
})
.catch(err => {
  // handle errors
});

```

--------------------------------

### Read and Parse OpenAPI/Swagger File

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

Use NodeJS built-in modules 'fs' and 'JSON' to read the content of an OpenAPI or Swagger file and parse it into a JavaScript object. Ensure the file is UTF-8 encoded.

```javascript
const fs = require('fs');
const fileData = fs.readFileSync('swagger.json', 'utf8');
const swaggerFile = JSON.parse(fileData);

```

--------------------------------

### Import Widdershins in JavaScript

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

Import the Widdershins library into your JavaScript program to enable its conversion functionality. This is the first step in using Widdershins programmatically.

```javascript
const widdershins = require('widdershins');

```

--------------------------------

### Write Markdown Output to File

Source: https://mermade.github.io/widdershins/ConvertingFilesBasicJS.html

After Widdershins successfully converts the API definition, write the resulting Markdown content to a specified file using NodeJS 'fs.writeFileSync'. This ensures the converted Markdown is saved.

```javascript
widdershins.convert(swaggerFile, options)
.then(markdownOutput => {
  // markdownOutput contains the converted markdown
  fs.writeFileSync('myOutput.md', markdownOutput, 'utf8');
})
.catch(err => {
  // handle errors
});

```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.