From 71afe186c9d24cdab009db11dffa1e6a61af8361 Mon Sep 17 00:00:00 2001
From: Dennis Wielepsky <dennis@wielepsky.de>
Date: Tue, 24 Sep 2024 18:21:17 +0200
Subject: [PATCH] add new configuration parser

---
 biome.json                |   5 +-
 src/configuration.mjs     |  44 +++++++++
 src/configuration.spec.js | 182 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 230 insertions(+), 1 deletion(-)
 create mode 100644 src/configuration.mjs
 create mode 100644 src/configuration.spec.js

diff --git a/biome.json b/biome.json
index 53668c9..7f49e17 100644
--- a/biome.json
+++ b/biome.json
@@ -19,7 +19,10 @@
 	"linter": {
 		"enabled": true,
 		"rules": {
-			"recommended": true
+			"recommended": true,
+			"performance": {
+				"noDelete": "off"
+			}
 		}
 	},
 	"javascript": {
diff --git a/src/configuration.mjs b/src/configuration.mjs
new file mode 100644
index 0000000..265dd79
--- /dev/null
+++ b/src/configuration.mjs
@@ -0,0 +1,44 @@
+const mustReadEnv = (variable) => {
+	const val = process.env[variable];
+	if (val === undefined || val.length === 0) {
+		throw new Error();
+	}
+
+	return val;
+};
+
+function readBoolean(variable) {
+	return process.env[variable] === "true" || process.env[variable] === "1";
+}
+
+function readInt(variable) {
+	if (process.env[variable] === undefined) {
+		return undefined;
+	}
+
+	return Number.parseInt(process.env[variable]);
+}
+
+export function configuration() {
+	const defaultDelay = 3600;
+	const config = {
+		github: {
+			username: mustReadEnv("GITHUB_USERNAME"),
+			token: process.env.GITHUB_TOKEN,
+			skipForks: readBoolean("SKIP_FORKS"),
+			privateRepositories: readBoolean("MIRROR_PRIVATE_REPOSITORIES"),
+		},
+		gitea: {
+			url: mustReadEnv("GITEA_URL"),
+			token: mustReadEnv("GITEA_TOKEN"),
+		},
+		dryRun: readBoolean("DRY_RUN"),
+		delay: readInt("DELAY") ?? defaultDelay,
+	};
+
+	if (config.github.privateRepositories && config.github.token === undefined) {
+		throw new Error();
+	}
+
+	return config;
+}
diff --git a/src/configuration.spec.js b/src/configuration.spec.js
new file mode 100644
index 0000000..ca7887c
--- /dev/null
+++ b/src/configuration.spec.js
@@ -0,0 +1,182 @@
+import { configuration } from "./configuration.mjs";
+
+const aGithubUsername = "A_GITHUB_USERNAME";
+const aGiteaUrl = "https://gitea.url";
+const aGiteaToken = "secret-gitea-token";
+const aGithubToken = "a-github-token";
+
+const variables = [
+	"DELAY",
+	"DRY_RUN",
+	"GITEA_TOKEN",
+	"GITEA_URL",
+	"GITHUB_TOKEN",
+	"GITHUB_USERNAME",
+	"MIRROR_PRIVATE_REPOSITORIES",
+	"SKIP_FORKS",
+];
+
+function provideMandatoryVariables() {
+	process.env.GITHUB_USERNAME = aGithubUsername;
+	process.env.GITEA_URL = aGiteaUrl;
+	process.env.GITEA_TOKEN = aGiteaToken;
+}
+
+const defaultDelay = 3600;
+describe("configuration", () => {
+	beforeEach(() => {
+		for (const variable of variables) {
+			delete process.env[variable];
+		}
+	});
+
+	it("reads configuration with default values", () => {
+		process.env.GITHUB_USERNAME = aGithubUsername;
+		process.env.GITEA_URL = aGiteaUrl;
+		process.env.GITEA_TOKEN = aGiteaToken;
+
+		const config = configuration();
+
+		expect(config.github.username).toEqual(aGithubUsername);
+		expect(config.github.token).toBeUndefined();
+		expect(config.github.skipForks).toEqual(false);
+
+		expect(config.gitea.url).toEqual(aGiteaUrl);
+		expect(config.gitea.token).toEqual(aGiteaToken);
+
+		expect(config.delay).toEqual(defaultDelay);
+	});
+
+	it("requires gitea url", () => {
+		provideMandatoryVariables();
+		delete process.env.GITEA_URL;
+
+		expect(() => configuration()).toThrow();
+	});
+
+	it("requires gitea token", () => {
+		provideMandatoryVariables();
+		delete process.env.GITEA_TOKEN;
+
+		expect(() => configuration()).toThrow();
+	});
+
+	it("requires github username", () => {
+		provideMandatoryVariables();
+		delete process.env.GITHUB_USERNAME;
+
+		expect(() => configuration()).toThrow();
+	});
+
+	it("reads github token", () => {
+		provideMandatoryVariables();
+		process.env.GITHUB_TOKEN = aGithubToken;
+
+		const config = configuration();
+
+		expect(config.github.token).toEqual(aGithubToken);
+	});
+
+	describe("dry run flag", () => {
+		it("treats true as true", () => {
+			provideMandatoryVariables();
+			process.env.DRY_RUN = "true";
+
+			const config = configuration();
+
+			expect(config.dryRun).toEqual(true);
+		});
+
+		it("treats 1 as true", () => {
+			provideMandatoryVariables();
+			process.env.DRY_RUN = "1";
+
+			const config = configuration();
+
+			expect(config.dryRun).toEqual(true);
+		});
+
+		it("treats missing flag as false", () => {
+			provideMandatoryVariables();
+
+			const config = configuration();
+
+			expect(config.dryRun).toEqual(false);
+		});
+	});
+
+	describe("skip forks flag", () => {
+		it("treats true as true", () => {
+			provideMandatoryVariables();
+			process.env.SKIP_FORKS = "true";
+
+			const config = configuration();
+
+			expect(config.github.skipForks).toEqual(true);
+		});
+
+		it("treats 1 as true", () => {
+			provideMandatoryVariables();
+			process.env.SKIP_FORKS = "1";
+
+			const config = configuration();
+
+			expect(config.github.skipForks).toEqual(true);
+		});
+
+		it("treats missing flag as false", () => {
+			provideMandatoryVariables();
+
+			const config = configuration();
+
+			expect(config.github.skipForks).toEqual(false);
+		});
+	});
+
+	describe("mirror private repositories flag", () => {
+		it("treats true as true", () => {
+			provideMandatoryVariables();
+			process.env.GITHUB_TOKEN = aGithubToken;
+			process.env.MIRROR_PRIVATE_REPOSITORIES = "true";
+
+			const config = configuration();
+
+			expect(config.github.privateRepositories).toEqual(true);
+		});
+
+		it("treats 1 as true", () => {
+			provideMandatoryVariables();
+			process.env.GITHUB_TOKEN = aGithubToken;
+
+			process.env.MIRROR_PRIVATE_REPOSITORIES = "1";
+
+			const config = configuration();
+
+			expect(config.github.privateRepositories).toEqual(true);
+		});
+
+		it("treats missing flag as false", () => {
+			provideMandatoryVariables();
+
+			const config = configuration();
+
+			expect(config.github.privateRepositories).toEqual(false);
+		});
+	});
+
+	it("requires a github token on private repository mirroring", () => {
+		provideMandatoryVariables();
+		process.env.MIRROR_PRIVATE_REPOSITORIES = "true";
+
+		expect(() => configuration()).toThrow();
+	});
+
+	it("parses delay", () => {
+		provideMandatoryVariables();
+		process.env.DELAY = "1200";
+
+		const config = configuration();
+
+		expect(config.delay).toEqual(1200);
+	});
+});