🚧Add folder and file inspection feature

[CalvinWilkinson]

Complete The Item Below

• I have updated the title without removing the 🚧 emoji.

Description

Add the ability to do the following with folders and files in the RepoClient.

1. Ability to check if a folder exists in a folder
2. Ability to check if a file exists in a folder
3. Ability to get a list of folders contained in another folder
4. Ability to get a list of files contained in another folder

Sample Code

import { Guards, Utils } from "../../deps.ts";
import { RepoClient } from "../../deps.ts";
import { FileOrFolder } from "../../deps.ts";

export class RepoFileService {
	private readonly fileRegex: RegExp;
	private readonly orgName: string;
	private readonly repoName: string;
	private readonly token: string;
	private readonly repoClient: RepoClient;

	constructor(orgName: string, repoName: string, token: string) {
		Guards.isNothing(orgName);
		Guards.isNothing(repoName);
		Guards.isNothing(token);

		this.fileRegex = /^.+\..+$/gm;
		this.orgName = orgName;
		this.repoName = repoName;
		this.token = token;

		this.repoClient = new RepoClient(orgName, repoName, token);
	}

	public async folderExists(folderPath: string): Promise<boolean> {
		Guards.isNothing(folderPath);

		// Strip leading and trailing slashes
		folderPath = folderPath.startsWith("/") ? folderPath.substring(1) : folderPath;
		folderPath = folderPath.endsWith("/") ? folderPath.substring(0, folderPath.length - 1) : folderPath;
		
		let parentFolder = "";

		if (this.fileRegex.test(folderPath)) {
			Utils.printGitHubError(`The file name '${folderPath}' is not a valid folder path.`);
			Deno.exit(1);
		}

		if (folderPath.includes("/")) {
			const parts = folderPath.split("/");
			parentFolder = parts.slice(0, parts.length - 1).join("/");
		}

		const filesAndFolders = await this.getFilesAndFolders(parentFolder);

		return filesAndFolders.some(f => this.isDir(f.type) && f.name === folderPath);
	}

	public async fileExists(filePath: string) : Promise<boolean> {
		Guards.isNothing(filePath);

		filePath = filePath.trim();

		let folderName = "";
		let fileName = "";
		
		if (filePath.includes("/")) {
			const parts = filePath.split("/");
			fileName = parts[parts.length - 1];
			
			if (!this.fileRegex.test(fileName)) {
				Utils.printGitHubError(`The file name '${fileName}' is not a valid file name.`);
				Deno.exit(1);
			}

			folderName = parts.slice(0, parts.length - 1).join("/");
		} else {
			if (!this.fileRegex.test(fileName)) {
				Utils.printGitHubError(`The file name '${fileName}' is not a valid file name.`);
				Deno.exit(1);
			}

			fileName = filePath;
		}

		const filesAndFolders = await this.getFilesAndFolders(folderName);

		return filesAndFolders.some(f => this.isFile(f.type) && f.name === fileName);
	}

	private async getFilesAndFolders(relativePath: string): Promise<FileOrFolder[]> {
		// Guards.isNothing(relativePath);

		const baseUrl = "https://api.github.com";
		const url = `${baseUrl}/repos/KinsonDigital/Velaptor/contents/${relativePath}`;
		
		const result = await fetch(url, {
			method: "GET",
			headers: {
				"Authorization": `Bearer ${this.token}`,
				"Accept": "application/vnd.github+json",
				"X-Github-Api-Version": "2022-11-28"
			},
		});
		
		if (result.status != 200) {
			console.error(result.statusText);
			Deno.exit(1);
		}
		
		const data = await result.json() as FileOrFolder[];

		return data;
	}

	private isFile(type: string): type is "file" {
		return type === "file";
	}

	private isDir(type: string): type is "dir" {
		return type === "dir";
	}
}

Acceptance Criteria

The items to complete to satisfy the Definition of Done.

Beta Give feedback

1. All unit tests executed and passed locally after PR work is complete. (Why? Refer to 'Additional Information' below.)

ToDo Items

The items to complete to satisfy the Definition of Done.

Beta Give feedback

1. Change type labels added to this issue. Refer to the Change Type Labels section below.
2. Priority label added to this issue. Refer to the Priority Type Labels section below.
3. Issue linked to the correct milestone (if applicable).

Issue Dependencies

No response

Related Work

No response

Additional Information:

Unit Tests

Reasons for local unit test execution:

• Unit tests might pass locally but not in the CI environment during the status check process or vice-versa.
• Tests might pass on the developer's machine but not necessarily on the code reviewer's machine.
• If you notice that the test status check has passed but the test failed locally, please notify a project maintainer!

💡Warning💡
If the unit tests pass remotely and are not executed locally, this means we could be letting a bug slip into production.
Though bugs will always exist in some capacity, we should all do our part to help prevent them from happening.

Change Type Labels

Change Type	Label
Bug Fixes	🐛bug
Breaking Changes	🧨breaking changes
New Feature	✨new feature
CICD Changes	♻️cicd
Config Changes	⚙️config
Performance Improvements	🏎️performance
Code Doc Changes	🗒️documentation/code
Product Doc Changes	📝documentation/product

Priority Type Labels

Priority Type	Label
Low Priority	low priority
Medium Priority	medium priority
High Priority	high priority

Code of Conduct

• I agree to follow this project's Code of Conduct.