Restore the Gulp build system

gulpfile.coffee

@@ -0,0 +1,49 @@
+import gulp from "gulp"
+import {spawn} from "node:child_process"
+import {readdir, readFile, rm, writeFile} from "node:fs/promises"
+import {join} from "node:path"
+import {env} from "node:process"
+
+# Builds the project.
+export build = ->
+	file = "src/client.coffee"
+	{default: {version}} = await import("./package.json", with: {type: "json"})
+	await writeFile file, (await readFile file, "utf8").replace /@_version = "\d+(\.\d+){2}"/, "@_version = \"#{version}\""
+	await npx "coffee", "--compile", "--no-header", "--output", "lib", "src"
+
+# Deletes all generated files.
+export clean = ->
+	await rm join("lib", file) for file from await readdir "lib" when not file.endsWith ".d.ts"
+	await rm join("var", file), recursive: yes for file from await readdir "var" when file isnt ".gitkeep"
+
+# Performs the static analysis of source code.
+export lint = ->
+	await npx "coffeelint", "--file=etc/coffeelint.json", "gulpfile.coffee", "example", "src", "test"
+
+# Publishes the package.
+export publish = ->
+	{default: {version}} = await import("./package.json", with: {type: "json"})
+	await run "gulp"
+	await run "npm", "publish", "--registry=#{registry}" for registry from ["https://registry.npmjs.org", "https://npm.pkg.github.com"]
+	await run "git", action..., "v#{version}" for action from [["tag"], ["push", "origin"]]
+
+# Runs the test suite.
+export test = ->
+	env.NODE_ENV = "test"
+	await npx "coffee", "--compile", "--map", "--no-header", "--output", "lib", "src", "test"
+	await run "node", "--enable-source-maps", "--test", "--test-reporter=spec", "lib/**/*_test.js"
+
+# Watches for file changes.
+export watch = ->
+	await npx "coffee", "--compile", "--no-header", "--output", "lib", "--watch", "src", "test"
+
+# Packages the project.
+export default gulp.series clean, build
+
+# Executes a command from a local package.
+npx = (command, args...) -> run "npm", "exec", "--", command, ...args
+
+# Spawns a new process using the specified command.
+run = (command, args...) -> new Promise (resolve, reject) ->
+	spawn command, args, shell: on, stdio: "inherit"
+		.on "close", (code) -> if code then reject(Error [command, args...].join(" ")) else resolve()