server: replace process.env with our env thoughout (#70)

Bonus: tests!

server/src/app.ts

@@ -20,8 +20,8 @@ app.use("/admin", admin)
 app.use("/health", health)
 
 app.get("/welcome", secretKey, (req, res) => {
-	const introContent = process.env.WELCOME_CONTENT
+	const introContent = config.welcome_content
-	const introTitle = process.env.WELCOME_TITLE
+	const introTitle = config.welcome_title
 	if (!introContent || !introTitle) {
 		return res.status(500).json({ error: "Missing welcome content" })
 	}

server/src/lib/__tests__/config.ts

@@ -0,0 +1,62 @@
+import { config } from "../config"
+
+describe("Config", () => {
+    it("should build a valid development config when no environment is set", () => {
+        const emptyEnv = {};
+        const result = config(emptyEnv);
+
+        expect(result).toHaveProperty("is_production", false)
+        expect(result).toHaveProperty("port")
+        expect(result).toHaveProperty("jwt_secret")
+        expect(result).toHaveProperty("drift_home")
+        expect(result).toHaveProperty("memory_db")
+        expect(result).toHaveProperty("enable_admin")
+        expect(result).toHaveProperty("secret_key")
+        expect(result).toHaveProperty("registration_password")
+        expect(result).toHaveProperty("welcome_content")
+        expect(result).toHaveProperty("welcome_title")
+    })
+
+    it("should fail when building a prod environment without SECRET_KEY", () => {
+        expect(() => config({ NODE_ENV: "production" }))
+            .toThrow(new Error("Missing environment variable: SECRET_KEY"))
+    })
+
+    it("should build a prod config with a SECRET_KEY", () => {
+        const result = config({ NODE_ENV: "production", SECRET_KEY: "secret" })
+
+        expect(result).toHaveProperty("is_production", true)
+        expect(result).toHaveProperty("secret_key", "secret")
+    })
+
+    describe("jwt_secret", () => {
+        it("should use default jwt_secret when environment is blank string", () => {
+            const result = config({ JWT_SECRET: "" })
+
+            expect(result).toHaveProperty("is_production", false)
+            expect(result).toHaveProperty("jwt_secret", "myjwtsecret")
+        })
+    })
+
+    describe("booleans", () => {
+        it("should parse 'true' as true", () => {
+            const result = config({ MEMORY_DB: "true" })
+
+            expect(result).toHaveProperty("memory_db", true)
+        })
+        it("should parse 'false' as false", () => {
+            const result = config({ MEMORY_DB: "false" })
+
+            expect(result).toHaveProperty("memory_db", false)
+        })
+        it("should fail when it is not parseable", () => {
+            expect(() => config({ MEMORY_DB: "foo" }))
+                .toThrow(new Error("Invalid boolean value: foo"))
+        })
+        it("should default to false when the string is empty", () => {
+            const result = config({ MEMORY_DB: "" })
+
+            expect(result).toHaveProperty("memory_db", false)
+        })
+    })
+})

server/src/lib/config.ts

@@ -6,11 +6,16 @@ type Config = {
 	memory_db: boolean
 	enable_admin: boolean
 	secret_key: string
-	registration_password: string
+	registration_password: string,
+	welcome_content: string | undefined,
+	welcome_title: string | undefined,
 }
 
-const config = (): Config => {
+type EnvironmentValue = string | undefined;
-	const stringToBoolean = (str: string | undefined): boolean => {
+type Environment = { [key: string]: EnvironmentValue }
+
+export const config = (env: Environment): Config => {
+	const stringToBoolean = (str: EnvironmentValue): boolean => {
 		if (str === "true") {
 			return true
 		} else if (str === "false") {
@@ -22,21 +27,21 @@ const config = (): Config => {
 		}
 	}
 
-	const throwIfUndefined = (str: string | undefined, name: string): string => {
+	const throwIfUndefined = (str: EnvironmentValue, name: string): string => {
 		if (str === undefined) {
 			throw new Error(`Missing environment variable: ${name}`)
 		}
 		return str
 	}
 
-	const defaultIfUndefined = (str: string | undefined, defaultValue: string): string => {
+	const defaultIfUndefined = (str: EnvironmentValue, defaultValue: string): string => {
 		if (str === undefined) {
 			return defaultValue
 		}
 		return str
 	}
 
-	const validNodeEnvs = (str: string | undefined) => {
+	const validNodeEnvs = (str: EnvironmentValue) => {
 		const valid = ["development", "production", "test"]
 		if (str && !valid.includes(str)) {
 			throw new Error(`Invalid NODE_ENV set: ${str}`)
@@ -47,26 +52,29 @@ const config = (): Config => {
 		}
 	}
 
-	const is_production = process.env.NODE_ENV === "production";
+	const is_production = env.NODE_ENV === "production";
 
-	const developmentDefault = (str: string | undefined, name: string, defaultValue: string): string => {
+	const developmentDefault = (str: EnvironmentValue, name: string, defaultValue: string): string => {
 		if (is_production) return throwIfUndefined(str, name);
 		return defaultIfUndefined(str, defaultValue);
 	}
 
-	validNodeEnvs(process.env.NODE_ENV)
+	validNodeEnvs(env.NODE_ENV)
 
 	const config: Config = {
-		port: process.env.PORT ? parseInt(process.env.PORT) : 3000,
+		port: env.PORT ? parseInt(env.PORT) : 3000,
-		jwt_secret: process.env.JWT_SECRET || "myjwtsecret",
+		jwt_secret: env.JWT_SECRET || "myjwtsecret",
-		drift_home: process.env.DRIFT_HOME || "~/.drift",
+		drift_home: env.DRIFT_HOME || "~/.drift",
 		is_production,
-		memory_db: stringToBoolean(process.env.MEMORY_DB),
+		memory_db: stringToBoolean(env.MEMORY_DB),
-		enable_admin: stringToBoolean(process.env.ENABLE_ADMIN),
+		enable_admin: stringToBoolean(env.ENABLE_ADMIN),
-		secret_key: developmentDefault(process.env.SECRET_KEY, "SECRET_KEY", "secret"),
+		secret_key: developmentDefault(env.SECRET_KEY, "SECRET_KEY", "secret"),
-		registration_password: process.env.REGISTRATION_PASSWORD || ""
+		registration_password: env.REGISTRATION_PASSWORD ?? "",
+		welcome_content: env.WELCOME_CONTENT,
+		welcome_title: env.WELCOME_TITLE
+
 	}
 	return config
 }
 
-export default config()
+export default config(process.env)