Basic /help functionality (#23)

* Use single quotes in generated version.ts file

* Update README

* Basic `/help` functionality

* Update unit tests

* Add tests around guild-only commands

README.md

@@ -76,10 +76,11 @@ Go to https://discordapi.com/permissions.html#378091424832 and paste in your bot
 
 ### Build the bot server
 
-Be sure to install dependencies:
+Be sure to install dependencies, and run a quick lint to generate needed files:
 
 ```sh
 $ npm ci
+$ npm run lint
 ```
 
 The first time you download the source, and each time the source code changes, you'll need to run this command before you run the bot:
@@ -112,7 +113,9 @@ $ pm2 start .
 
 ## Commands
 
-\[TBD\]
+### /help
+
+Prints the list of commands.
 
 ## Contributing
 

package.json

@@ -19,7 +19,7 @@
 		"prebuild": "npm run lint",
 		"build": "npm run build:only",
 		"build:only": "rm -rf dist && ./node_modules/.bin/tsc -p tsconfig.prod.json",
-		"export-version": "./node_modules/.bin/genversion ./src/version.ts -esd",
+		"export-version": "./node_modules/.bin/genversion ./src/version.ts -es",
 		"test": "./node_modules/.bin/jest",
 		"test:watch": "npm run test -- --watch --coverage=false"
 	},

src/commands/__snapshots__/help.test.ts.snap

@@ -0,0 +1,25 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`help presents an ephemeral embed with all available global and guild-bound commands 1`] = `
+Object {
+  "fields": Array [
+    Object {
+      "name": "\`/help\`",
+      "value": "Prints the list of commands",
+    },
+  ],
+  "title": "All commands",
+}
+`;
+
+exports[`help presents an ephemeral embed with all available global commands 1`] = `
+Object {
+  "fields": Array [
+    Object {
+      "name": "\`/help\`",
+      "value": "Prints the list of commands",
+    },
+  ],
+  "title": "All commands",
+}
+`;

src/commands/help.test.ts

@@ -1,15 +1,80 @@
+import type { EmbedBuilder } from 'discord.js';
 import { help } from './help';
 
+const { allCommands: realAllCommands } = jest.requireActual<typeof import('./index')>('./index');
+const mockAllCommands = new Map<string, Command>();
+
+jest.mock('./index', () => ({
+	allCommands: mockAllCommands,
+}));
+
 describe('help', () => {
-	test("it's just a Hello World", async () => {
-		const mockReply = jest.fn();
-		const context = {
+	const mockReply = jest.fn();
+	let context: CommandContext;
+
+	beforeEach(() => {
+		mockAllCommands.clear();
+		realAllCommands.forEach((value, key) => mockAllCommands.set(key, value));
+
+		context = {
+			guild: null,
 			reply: mockReply,
 		} as unknown as CommandContext;
+	});
+
+	test('presents an ephemeral embed with all available global commands', async () => {
+		context = { ...context, guild: null };
+
+		await expect(help.execute(context)).resolves.toBeUndefined();
+		expect(mockReply).toHaveBeenCalledOnce();
+		expect(mockReply).toHaveBeenCalledWith({
+			embeds: [expect.toBeObject()],
+			ephemeral: true,
+		});
+		const call = mockReply.mock.calls[0] as [{ embeds: [EmbedBuilder] }];
+		const embed = call[0].embeds[0];
+		expect(embed.data.fields).toBeArrayOfSize(mockAllCommands.size);
+		expect(embed.data).toMatchSnapshot();
+	});
+
+	test('presents an ephemeral embed with all available global and guild-bound commands', async () => {
+		context = {
+			...context,
+			guild: { id: 'the-guild-1234' },
+		} as unknown as CommandContext;
 
 		await expect(help.execute(context)).resolves.toBeUndefined();
+		expect(mockReply).toHaveBeenCalledOnce();
+		expect(mockReply).toHaveBeenCalledWith({
+			embeds: [expect.toBeObject()],
+			ephemeral: true,
+		});
+		const call = mockReply.mock.calls[0] as [{ embeds: [EmbedBuilder] }];
+		const embed = call[0].embeds[0];
+		expect(embed.data.fields).toBeArrayOfSize(mockAllCommands.size);
+		expect(embed.data).toMatchSnapshot();
+	});
 
+	test("doesn't show a guild-only command when in DMs", async () => {
+		const cmd: GuildedCommand = {
+			name: 'canttouchthis-do-do-do-do', // this test will break if we ever have a command with this name
+			description: "Can't touch this. (This is a test.)",
+			requiresGuild: true,
+			dmPermission: false,
+			execute() {
+				// nop
+			},
+		};
+		mockAllCommands.set(cmd.name, cmd);
+
+		await expect(help.execute(context)).resolves.toBeUndefined();
 		expect(mockReply).toHaveBeenCalledOnce();
-		expect(mockReply).toHaveBeenCalledWith('Hello, world!');
+		expect(mockReply).toHaveBeenCalledWith({
+			embeds: [expect.toBeObject()],
+			ephemeral: true,
+		});
+		const call = mockReply.mock.calls[0] as [{ embeds: [EmbedBuilder] }];
+		const embed = call[0].embeds[0];
+		expect(embed.data.fields).toBeArrayOfSize(mockAllCommands.size - 1);
 	});
 });

src/commands/help.ts

@@ -1,9 +1,43 @@
+import { EmbedBuilder } from 'discord.js';
+
 export const help: GlobalCommand = {
 	name: 'help',
 	description: 'Prints the list of commands',
 	requiresGuild: false,
-	async execute({ reply }) {
-		// TODO: finish this command
-		await reply('Hello, world!');
+	async execute({ guild, reply }) {
+		// Dynamic import here b/c ./index depends on this file
+		const { allCommands } = await import('./index');
+
+		const embed = new EmbedBuilder() //
+			.setTitle('All commands');
+
+		function embedCommand(command: Command): void {
+			embed.addFields({
+				name: `\`/${command.name}\``, // i.e. `/help`
+				value: command.description,
+			});
+		}
+
+		for (const command of allCommands.values()) {
+			if (guild) {
+				// We're in a guild. We should check the user's permissions,
+				// and skip this command if they aren't allowed to use it.
+				// TODO: Grab the guild's configured permissions for this channel
+				embedCommand(command);
+				continue;
+			}
+
+			// We're in DMs; command should have dmPermission if we're to print it.
+			// Discord defaults dmPermission to `true`, so `undefined` should behave that way.
+			// See https://discordjs.guide/interactions/slash-commands.html#dm-permission
+			if (command.dmPermission === false) continue;
+
+			embedCommand(command);
+		}
+
+		await reply({
+			embeds: [embed],
+			ephemeral: true,
+		});
 	},
 };