2023-09-06T09:28:44.713Z

.gitignore

@@ -1,4 +1,5 @@
 node_modules
 .vscode
 tsconfig.temp.json
-*.prompt.*
+*.prompt.*
+dist

src/032-typescript-only-features/115-enums.problem.ts

@@ -0,0 +1,56 @@
+import { expect, it, vi } from "vitest";
+
+const LogLevel = {
+  DEBUG: 0,
+  INFO: 1,
+  WARN: 2,
+  ERROR: 3,
+};
+
+function log(opts: { globalLogLevel: number; level: number; message: string }) {
+  if (opts.level >= opts.globalLogLevel) {
+    console.log(opts.message);
+  }
+}
+
+it("Should log if the level is higher than the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.ERROR,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).toHaveBeenCalledWith("Hello!");
+});
+
+it("Should log if the level is equal to the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.INFO,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).toHaveBeenCalledWith("Hello!");
+});
+
+it("Should not log if the level is lower than the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.DEBUG,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).not.toHaveBeenCalled();
+});
+
+it("Should give you a TS error if you pass an invalid log level", () => {
+  log({
+    globalLogLevel: LogLevel.INFO,
+    // @ts-expect-error
+    level: 123,
+    message: "Hello!",
+  });
+});

src/032-typescript-only-features/115-enums.solution.1.ts

@@ -0,0 +1,60 @@
+import { expect, it, vi } from "vitest";
+
+enum LogLevel {
+  DEBUG,
+  INFO,
+  WARN,
+  ERROR,
+}
+
+function log(opts: {
+  globalLogLevel: LogLevel;
+  level: LogLevel;
+  message: string;
+}) {
+  if (opts.level >= opts.globalLogLevel) {
+    console.log(opts.message);
+  }
+}
+
+it("Should log if the level is higher than the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.ERROR,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).toHaveBeenCalledWith("Hello!");
+});
+
+it("Should log if the level is equal to the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.INFO,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).toHaveBeenCalledWith("Hello!");
+});
+
+it("Should not log if the level is lower than the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.DEBUG,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).not.toHaveBeenCalled();
+});
+
+it("Should give you a TS error if you pass an invalid log level", () => {
+  log({
+    globalLogLevel: LogLevel.INFO,
+    // @ts-expect-error
+    level: 123,
+    message: "Hello!",
+  });
+});

src/032-typescript-only-features/115-enums.solution.2.ts

@@ -0,0 +1,60 @@
+import { expect, it, vi } from "vitest";
+
+enum LogLevel {
+  DEBUG = 0,
+  INFO = 1,
+  WARN = 2,
+  ERROR = 3,
+}
+
+function log(opts: {
+  globalLogLevel: LogLevel;
+  level: LogLevel;
+  message: string;
+}) {
+  if (opts.level >= opts.globalLogLevel) {
+    console.log(opts.message);
+  }
+}
+
+it("Should log if the level is higher than the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.ERROR,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).toHaveBeenCalledWith("Hello!");
+});
+
+it("Should log if the level is equal to the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.INFO,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).toHaveBeenCalledWith("Hello!");
+});
+
+it("Should not log if the level is lower than the global log level", () => {
+  const consoleLog = vi.spyOn(console, "log");
+  log({
+    globalLogLevel: LogLevel.INFO,
+    level: LogLevel.DEBUG,
+    message: "Hello!",
+  });
+
+  expect(consoleLog).not.toHaveBeenCalled();
+});
+
+it("Should give you a TS error if you pass an invalid log level", () => {
+  log({
+    globalLogLevel: LogLevel.INFO,
+    // @ts-expect-error
+    level: 123,
+    message: "Hello!",
+  });
+});

src/032-typescript-only-features/116-string-enums.problem.ts

@@ -0,0 +1,44 @@
+import { it } from "vitest";
+
+const Method = {
+  GET: "GET",
+  POST: "POST",
+  PUT: "PUT",
+  DELETE: "DELETE",
+};
+
+const request = (url: string, method: "GET" | "POST" | "PUT" | "DELETE") => {
+  // ...
+};
+
+it("Should force you to use the enum values", () => {
+  request(
+    "https://example.com",
+    // @ts-expect-error
+    "GET",
+  );
+
+  request(
+    "https://example.com",
+    // @ts-expect-error
+    "POST",
+  );
+
+  request("https://example.com", Method.GET);
+  request("https://example.com", Method.POST);
+});
+
+it("Should give you an error if you pass a different enum with the same value", () => {
+  enum Method2 {
+    GET = "GET",
+    POST = "POST",
+    PUT = "PUT",
+    DELETE = "DELETE",
+  }
+
+  request(
+    "https://example.com",
+    // @ts-expect-error
+    Method2.GET,
+  );
+});

src/032-typescript-only-features/116-string-enums.solution.ts

@@ -0,0 +1,44 @@
+import { it } from "vitest";
+
+enum Method {
+  GET = "GET",
+  POST = "POST",
+  PUT = "PUT",
+  DELETE = "DELETE",
+}
+
+const request = (url: string, method: Method) => {
+  // ...
+};
+
+it("Should force you to use the enum values", () => {
+  request(
+    "https://example.com",
+    // @ts-expect-error
+    "GET",
+  );
+
+  request(
+    "https://example.com",
+    // @ts-expect-error
+    "POST",
+  );
+
+  request("https://example.com", Method.GET);
+  request("https://example.com", Method.POST);
+});
+
+it("Should give you an error if you pass a different enum with the same value", () => {
+  enum Method2 {
+    GET = "GET",
+    POST = "POST",
+    PUT = "PUT",
+    DELETE = "DELETE",
+  }
+
+  request(
+    "https://example.com",
+    // @ts-expect-error
+    Method2.GET,
+  );
+});