Initial commit

packages/tools/src/tsconfig.ts

@@ -0,0 +1,66 @@
+import path from 'node:path'
+import { inspect } from 'node:util'
+
+import type {
+	createProgram,
+	parseJsonConfigFileContent,
+	readConfigFile,
+	sys,
+	CompilerOptions as TSCompilerOptions,
+} from 'typescript'
+
+export type { TSCompilerOptions }
+
+interface TSModule {
+	readConfigFile: typeof readConfigFile
+	parseJsonConfigFileContent: typeof parseJsonConfigFileContent
+	sys: typeof sys
+	createProgram: typeof createProgram
+}
+
+/**
+ * TypeScript helpers. This is a class so that we can dynamically import the TypeScript module
+ * to reduce runx start time for commands that don't use the typescript package.
+ *
+ * @example
+ *
+ * ```ts
+ * const tsHelpers = await new TSHelpers().init()
+ * const { ts } = tsHelpers
+ * const tsConfig = tsHelpers.getTSConfig()
+ * ts.createProgram(entryPoints, tsConfig).emit()
+ * ```
+ */
+export class TSHelpers {
+	#ts: TSModule | undefined
+	public get ts(): TSModule {
+		if (!this.#ts) {
+			throw new Error('TSHelpers not initialized. Call init() first.')
+		}
+		return this.#ts
+	}
+
+	async init(): Promise<TSHelpers> {
+		this.#ts = (await import('typescript')) as TSModule
+		return this
+	}
+
+	getTSConfig(configPath = 'tsconfig.json'): TSCompilerOptions {
+		const absolutePath = path.resolve(configPath)
+		const configFile = this.ts.readConfigFile(absolutePath, (p) => this.ts.sys.readFile(p))
+		if (configFile.error) {
+			throw new Error(`Failed to read tsconfig: ${inspect(configFile.error)}`)
+		}
+
+		const parsed = this.ts.parseJsonConfigFileContent(
+			configFile.config,
+			this.ts.sys,
+			path.dirname(absolutePath)
+		)
+		if (parsed.errors.length > 0) {
+			throw new Error(`Failed to parse tsconfig: ${inspect(parsed.errors)}`)
+		}
+
+		return parsed.options
+	}
+}