fix(extractor): keep the heritage clause of an anonymous default class

packages/dtsx/test/anonymous-default-class.test.tsadded+93-0

Changes to packages/dtsx/test/anonymous-default-class.test.ts

		@@ -0,0 +1,93 @@
	1	+/**
	2	+ * An anonymous default-exported class with a heritage clause lost it, and its
	3	+ * members with it:
	4	+ *
	5	+ * export default class extends Base { c = 2 }
	6	+ *
	7	+ * emitted `export default class extends {}`, which does not parse.
	8	+ * `extractClass` read `extends` (or `implements`) as the class name. The class
	9	+ * now gets a helper name, `__dtsx_default_class__`, as a default-exported
	10	+ * expression gets `__dtsx_default_export__`.
	11	+ */
	12	+import { describe, expect, it } from 'bun:test'
	13	+import { mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises'
	14	+import { tmpdir } from 'node:os'
	15	+import { join } from 'node:path'
	16	+import { generate } from '../src/generator'
	17	+import { runTsc } from './helpers/tsc'
	18	+import { processCode } from './test-utils'
	19	+
	20	+/** Type-check `consumer` against the generated declarations as `./index`. */
	21	+async function checkConsumer(dts: string, consumer: string): Promise<string> {
	22	+ const dir = await mkdtemp(join(tmpdir(), 'dtsx-anonymous-class-'))
	23	+ try {
	24	+ await writeFile(join(dir, 'index.d.ts'), dts)
	25	+ await writeFile(join(dir, 'use.ts'), consumer)
	26	+ return runTsc(dir, ['index.d.ts', 'use.ts']).output
	27	+ }
	28	+ finally {
	29	+ await rm(dir, { recursive: true, force: true })
	30	+ }
	31	+}
	32	+
	33	+describe('anonymous default class with a heritage clause', () => {
	34	+ it.each([
	35	+ [
	36	+ 'extends',
	37	+ 'class Base { b = 1 }\nexport default class extends Base { c = 2 }\n',
	38	+ 'export default class __dtsx_default_class__ extends Base {',
	39	+ 'import C from \'./index\'\nconst c = new C()\nconst n: number = c.b + c.c\nexport {}\n',
	40	+ ],
	41	+ [
	42	+ 'implements',
	43	+ 'interface Named { name(): string }\nexport default class implements Named { name(): string { return \'x\' } }\n',
	44	+ 'export default class __dtsx_default_class__ implements Named {',
	45	+ 'import C from \'./index\'\nconst s: string = new C().name()\nexport {}\n',
	46	+ ],
	47	+ [
	48	+ 'abstract, implements',
	49	+ 'export default abstract class implements Iterable<number> { abstract [Symbol.iterator](): Iterator<number> }\n',
	50	+ 'export default abstract class __dtsx_default_class__ implements Iterable<number> {',
	51	+ 'import C from \'./index\'\nexport class D extends C { *[Symbol.iterator](): Iterator<number> { yield 1 } }\nconst all: number[] = [...new D()]\n',
	52	+ ],
	53	+ [
	54	+ 'generic, extends',
	55	+ 'class Box<T> { value!: T }\nexport default class<T> extends Box<T> { label = \'\' }\n',
	56	+ 'export default class AnonymousClass<T> extends Box<T> {',
	57	+ 'import C from \'./index\'\nconst c = new C<number>()\nconst n: number = c.value\nconst s: string = c.label\nexport {}\n',
	58	+ ],
	59	+ [
	60	+ 'beside a class named AnonymousClass',
	61	+ 'interface Marker {}\nexport class AnonymousClass { tag = \'real\' }\nexport default class implements Marker { id = 1 }\n',
	62	+ 'export default class __dtsx_default_class__ implements Marker {',
	63	+ 'import C, { AnonymousClass } from \'./index\'\nconst n: number = new C().id\nconst s: string = new AnonymousClass().tag\nexport {}\n',
	64	+ ],
	65	+ ])('keeps the clause and the members: %s', async (_label, code, header, consumer) => {
	66	+ const output = processCode(code)
	67	+ expect(output).toContain(header)
	68	+ expect(await checkConsumer(output, consumer)).toBe('')
	69	+ })
	70	+
	71	+ it.each([
	72	+ ['ambient class', 'export declare class implements { c: number }\n', 'export declare class implements {'],
	73	+ ['default class', 'export default class implements { c = 1 }\n', 'export default class implements {'],
	74	+ ])('keeps a class named implements: %s', (_label, code, header) => {
	75	+ expect(processCode(code)).toContain(header)
	76	+ })
	77	+
	78	+ it('keeps the clause in a bundle', async () => {
	79	+ const cwd = await mkdtemp(join(tmpdir(), 'dtsx-anonymous-class-bundle-'))
	80	+ try {
	81	+ await mkdir(join(cwd, 'src'))
	82	+ await writeFile(join(cwd, 'src', 'index.ts'), 'class Base { b = 1 }\nexport default class extends Base { c = 2 }\nexport * from \'./other\'\n')
	83	+ await writeFile(join(cwd, 'src', 'other.ts'), 'export class AnonymousClass { real = \'yes\' }\nexport type Label = `AnonymousClass-${string}`\n')
	84	+ await generate({ cwd, root: 'src', outdir: 'dist', entrypoints: ['index.ts'], bundle: true, clean: false, keepComments: false })
	85	+ expect(await readFile(join(cwd, 'dist', 'index.d.ts'), 'utf8')).toContain('class __dtsx_default_class__ extends Base {')
	86	+ await writeFile(join(cwd, 'dist', 'use.ts'), 'import C, { AnonymousClass, type Label } from \'./index\'\nconst n: number = new C().b + new C().c\nconst real: string = new AnonymousClass().real\nconst label: Label = \'AnonymousClass-ok\'\nexport {}\n')
	87	+ expect(runTsc(join(cwd, 'dist'), ['index.d.ts', 'use.ts']).output).toBe('')
	88	+ }
	89	+ finally {
	90	+ await rm(cwd, { recursive: true, force: true })
	91	+ }
	92	+ })
	93	+})