Implement stdin input with optional "-" as the file name. (#3290)

* Implement stdin input with optional "-" as the file name.
Set default output format to "es" to save CLI typing for the most common case.

closes #1440
closes #3276

* * Test if we can delete process.stdin on CI
* Only allow '-' to use stdin with the JS API
* Use locally installed shx
* Add test for stdin read error

Co-authored-by: Lukas Taegert-Atkinson <lukastaegert@users.noreply.github.com>

cli/run/index.ts

@@ -3,6 +3,7 @@ import relative from 'require-relative';
 import { WarningHandler } from '../../src/rollup/types';
 import mergeOptions, { GenericConfigObject } from '../../src/utils/mergeOptions';
 import { getAliasName } from '../../src/utils/relativeId';
+import { stdinName } from '../../src/utils/stdin';
 import { handleError } from '../logging';
 import batchWarnings from './batchWarnings';
 import build from './build';
@@ -101,6 +102,7 @@ function execute (configFile: string, configs: GenericConfigObject[], command: a
 		for (const config of configs) {
 			promise = promise.then(() => {
 				const warnings = batchWarnings();
+				handleMissingInput(command, config);
 				const { inputOptions, outputOptions, optionError } = mergeOptions({
 					command,
 					config,
@@ -115,3 +117,9 @@ function execute (configFile: string, configs: GenericConfigObject[], command: a
 		return promise;
 	}
 }
+
+function handleMissingInput(command: any, config: GenericConfigObject) {
+	if (!(command.input || config.input || config.input === '' || process.stdin.isTTY)) {
+		command.input = stdinName;
+	}
+}

src/utils/defaultPlugin.ts

@@ -2,13 +2,14 @@ import { Plugin, ResolveIdHook } from '../rollup/types';
 import { error } from './error';
 import { lstatSync, readdirSync, readFile, realpathSync } from './fs';
 import { basename, dirname, isAbsolute, resolve } from './path';
+import { readStdin, stdinName } from './stdin';
 
 export function getRollupDefaultPlugin(preserveSymlinks: boolean): Plugin {
 	return {
 		name: 'Rollup Core',
 		resolveId: createResolveId(preserveSymlinks) as ResolveIdHook,
 		load(id) {
-			return readFile(id);
+			return id === stdinName ? readStdin() : readFile(id);
 		},
 		resolveFileUrl({ relativePath, format }) {
 			return relativeUrlMechanisms[format](relativePath);
@@ -58,6 +59,8 @@ function createResolveId(preserveSymlinks: boolean) {
 			});
 		}
 
+		if (source === stdinName) return source;
+
 		// external modules (non-entry modules that start with neither '.' or '/')
 		// are skipped at this stage.
 		if (importer !== undefined && !isAbsolute(source) && source[0] !== '.') return null;

src/utils/mergeOptions.ts

@@ -5,6 +5,8 @@ import {
 	WarningHandlerWithDefault
 } from '../rollup/types';
 
+import { stdinName } from './stdin';
+
 export interface GenericConfigObject {
 	[key: string]: unknown;
 }
@@ -208,6 +210,7 @@ function getInputOptions(
 	defaultOnWarnHandler: WarningHandler
 ): InputOptions {
 	const getOption = createGetOption(config, command);
+	const input = getOption('input', []);
 
 	const inputOptions: InputOptions = {
 		acorn: config.acorn,
@@ -220,7 +223,7 @@ function getInputOptions(
 		experimentalTopLevelAwait: getOption('experimentalTopLevelAwait'),
 		external: getExternal(config, command) as any,
 		inlineDynamicImports: getOption('inlineDynamicImports', false),
-		input: getOption('input', []),
+		input,
 		manualChunks: getOption('manualChunks'),
 		moduleContext: config.moduleContext as any,
 		onwarn: getOnWarn(config, defaultOnWarnHandler),
@@ -234,6 +237,13 @@ function getInputOptions(
 		watch: config.watch as any
 	};
 
+	if (
+		config.watch &&
+		(input === stdinName || (Array.isArray(input) && input.indexOf(stdinName) >= 0))
+	) {
+		throw new Error('watch mode is incompatible with stdin input');
+	}
+
 	// support rollup({ cache: prevBuildObject })
 	if (inputOptions.cache && (inputOptions.cache as any).cache)
 		inputOptions.cache = (inputOptions.cache as any).cache;
@@ -250,6 +260,7 @@ function getOutputOptions(
 
 	// Handle format aliases
 	switch (format) {
+		case undefined:
 		case 'esm':
 		case 'module':
 			format = 'es';
@@ -273,7 +284,7 @@ function getOutputOptions(
 		externalLiveBindings: getOption('externalLiveBindings', true),
 		file: getOption('file'),
 		footer: getOption('footer'),
-		format: format === 'esm' ? 'es' : format,
+		format,
 		freeze: getOption('freeze', true),
 		globals: getOption('globals'),
 		indent: getOption('indent', true),

src/utils/stdin.ts

@@ -0,0 +1,54 @@
+export const stdinName = '-';
+
+let stdinResult: string | Error | null = null;
+const pending: { reject: Function; resolve: Function }[] = [];
+
+export function readStdin() {
+	return new Promise<string>((resolve, reject) => {
+		if (typeof process == 'undefined' || typeof process.stdin == 'undefined') {
+			reject(new Error('stdin input is invalid in browser'));
+			return;
+		}
+		pending.push({ resolve, reject });
+		processPending();
+		if (pending.length === 1) {
+			// stdin is read once - all callers will get the same result
+
+			const chunks: Buffer[] = [];
+			process.stdin.setEncoding('utf8');
+			process.stdin
+				.on('data', chunk => {
+					if (stdinResult === null) {
+						chunks.push(chunk);
+					}
+				})
+				.on('end', () => {
+					if (stdinResult === null) {
+						stdinResult = chunks.join('');
+						chunks.length = 0;
+					}
+					processPending();
+				})
+				.on('error', err => {
+					if (stdinResult === null) {
+						stdinResult = err instanceof Error ? err : new Error(err);
+						chunks.length = 0;
+					}
+					processPending();
+				});
+			process.stdin.resume();
+		}
+	});
+
+	function processPending() {
+		if (stdinResult !== null) {
+			for (let it; (it = pending.shift()); ) {
+				if (typeof stdinResult == 'string') {
+					it.resolve(stdinResult);
+				} else {
+					it.reject(stdinResult);
+				}
+			}
+		}
+	}
+}

test/cli/index.js

@@ -23,8 +23,15 @@ runTestSuiteWithSamples(
 			done => {
 				process.chdir(config.cwd || dir);
 
-				const command =
-					'node ' + path.resolve(__dirname, '../../dist/bin') + path.sep + config.command;
+				const command = config.command
+					.replace(
+						/(^| )rollup /g,
+						`node ${path.resolve(__dirname, '../../dist/bin')}${path.sep}rollup `
+					)
+					.replace(
+						/(^| )shx /g,
+						`node ${path.resolve(__dirname, '../../node_modules/.bin')}${path.sep}shx `
+					);
 
 				const childProcess = exec(
 					command,

test/cli/samples/stdin-multiple-targets/_config.js

@@ -0,0 +1,4 @@
+module.exports = {
+	description: 'uses stdin in multiple targets',
+	command: `shx echo "import {PRINT as p} from './a'; import C from  './b'; 0 && fail() || p(C); export {C as value, p as print}" | rollup -c`
+};

test/cli/samples/stdin-multiple-targets/_expected/cjs.js

@@ -0,0 +1,12 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+const PRINT = x => console.log(x);
+
+var C = 123;
+
+PRINT(C);
+
+exports.print = PRINT;
+exports.value = C;

test/cli/samples/stdin-multiple-targets/_expected/es.js

@@ -0,0 +1,7 @@
+const PRINT = x => console.log(x);
+
+var C = 123;
+
+PRINT(C);
+
+export { PRINT as print, C as value };

test/cli/samples/stdin-multiple-targets/a.mjs

@@ -0,0 +1 @@
+export const PRINT = x => console.log(x);

test/cli/samples/stdin-multiple-targets/b.mjs

@@ -0,0 +1 @@
+export default 123;

test/cli/samples/stdin-multiple-targets/rollup.config.js

@@ -0,0 +1,16 @@
+export default [
+	{
+		input: '-',
+		output: {
+			file: '_actual/cjs.js',
+			format: 'cjs'
+		}
+	},
+	{
+		input: '-',
+		output: {
+			file: '_actual/es.js',
+			format: 'es'
+		}
+	}
+];

test/cli/samples/stdin-no-dash/_config.js

@@ -0,0 +1,4 @@
+module.exports = {
+	description: 'stdin input with no dash on CLI',
+	command: `shx mkdir -p _actual && shx echo "0 && fail() || console.log('PASS');" | rollup > _actual/out.js`
+};

test/cli/samples/stdin-no-dash/_expected/out.js

@@ -0,0 +1 @@
+console.log('PASS');

test/cli/samples/stdin-self-import/_config.js

@@ -0,0 +1,4 @@
+module.exports = {
+	description: 'stdin input of code that imports a copy of itself',
+	command: `shx mkdir -p _actual && shx cat input.txt | rollup -f cjs --silent > _actual/out.js`
+};

test/cli/samples/stdin-self-import/_expected/out.js

@@ -0,0 +1,11 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+let b = 2;
+var a = 4;
+
+console.log(a, b);
+
+exports.b = b;
+exports.default = a;

test/cli/samples/stdin-self-import/input.txt

@@ -0,0 +1,10 @@
+import a from "-";
+import { b as c } from "-";
+
+export let b = 2;
+export default 4;
+
+if (a > c)
+	console.log(a, c);
+else
+	console.log(c, a);

test/cli/samples/stdin-with-dash/_config.js

@@ -0,0 +1,4 @@
+module.exports = {
+	description: 'stdin input with dash on CLI',
+	command: `shx mkdir -p _actual && shx echo "0 && fail() || console.log('PASS');" | rollup - > _actual/out.js`
+};

test/cli/samples/stdin-with-dash/_expected/out.js

@@ -0,0 +1 @@
+console.log('PASS');

test/function/index.js

@@ -177,14 +177,14 @@ runTestSuiteWithSamples('function', path.resolve(__dirname, 'samples'), (dir, co
 												.join('\n')}`
 										);
 									}
-
 									if (config.show) console.groupEnd();
-
 									if (unintendedError) throw unintendedError;
+									if (config.after) config.after();
 								});
 						});
 				})
 				.catch(err => {
+					if (config.after) config.after();
 					if (config.error) {
 						compareError(err, config.error);
 					} else {

test/function/samples/stdin-not-present/_config.js

@@ -0,0 +1,23 @@
+const savedStdin = process.stdin;
+
+module.exports = {
+	description: 'stdin reads should fail if process.stdin not present (as in a browser)',
+	options: {
+		input: '-'
+	},
+	before() {
+		delete process.stdin;
+	},
+	after() {
+		process.stdin = savedStdin;
+	},
+	error: {
+		// TODO we probably want a better error code here as this one is confusing
+		code: 'PLUGIN_ERROR',
+		hook: 'load',
+		// TODO the error message does not need to refer to browsers as there are other possible scenarios
+		message: 'Could not load -: stdin input is invalid in browser',
+		plugin: 'Rollup Core',
+		watchFiles: ['-']
+	}
+};

test/function/samples/stdin-not-present/main.js

@@ -0,0 +1 @@
+assert.equal( 1, 1 );

test/function/samples/stdin-read-error/_config.js

@@ -0,0 +1,29 @@
+const { Readable } = require('stream');
+const savedStdin = process.stdin;
+
+module.exports = {
+	description: 'stdin reads should fail if process.stdin not present (as in a browser)',
+	options: {
+		input: '-'
+	},
+	before() {
+		delete process.stdin;
+		process.stdin = new Readable({
+			encoding: 'utf8',
+			read() {
+				const error = new Error('Stream is broken.');
+				return this.destroy ? this.destroy(error) : this.emit('error', error);
+			}
+		});
+	},
+	after() {
+		process.stdin = savedStdin;
+	},
+	error: {
+		code: 'PLUGIN_ERROR',
+		hook: 'load',
+		message: 'Could not load -: Stream is broken.',
+		plugin: 'Rollup Core',
+		watchFiles: ['-']
+	}
+};

test/function/samples/stdin-read-error/main.js

@@ -0,0 +1 @@
+assert.equal( 1, 1 );

test/function/samples/stdin-watch/_config.js

@@ -0,0 +1,11 @@
+module.exports = {
+	description: 'throws when using the "watch" option with stdin "-"',
+	options: {
+		input: '-',
+		watch: true
+	},
+	error: {
+		// TODO add an error code
+		message: 'watch mode is incompatible with stdin input'
+	}
+};

test/function/samples/stdin-watch/main.js

@@ -0,0 +1 @@
+assert.equal( 1, 1 );

test/misc/sanity-checks.js

@@ -111,7 +111,7 @@ describe('sanity checks', () => {
 			});
 	});
 
-	it('throws on missing format option', () => {
+	it('throws on incorrect bundle.generate format option', () => {
 		const warnings = [];
 
 		return rollup
@@ -122,11 +122,28 @@ describe('sanity checks', () => {
 			})
 			.then(bundle => {
 				assert.throws(() => {
-					bundle.generate({ file: 'x' });
+					bundle.generate({ file: 'x', format: 'vanilla' });
 				}, /You must specify "output\.format", which can be one of "amd", "cjs", "system", "esm", "iife" or "umd"./);
 			});
 	});
 
+	it('defaults to output format `es` if not specified', () => {
+		const warnings = [];
+
+		return rollup
+			.rollup({
+				input: 'x',
+				plugins: [loader({ x: `export function foo(x){ console.log(x); }` })],
+				onwarn: warning => warnings.push(warning)
+			})
+			.then(bundle => {
+				return bundle.generate({});
+			})
+			.then(({ output: [{ code }] }) => {
+				assert.equal(code, `function foo(x){ console.log(x); }\n\nexport { foo };\n`);
+			});
+	});
+
 	it('reuses existing error object', () => {
 		let error;