feat: static hermes support (undocumented)

hermes-shermes

Author: ChALkeR

bin/find-binary.js

@@ -60,6 +60,7 @@ function findBinaryOnce(name) {
     case 'ladybird-js': // naming by esvu
     case 'engine262':
       return findFile([jsvu, esvu])
+    case 'shermes': // our temporary name for static hermes
     case 'xs':
       return findFile([jsvu, esvu], false)
     case 'electron':

bin/index.js

@@ -20,6 +20,7 @@ const DEFAULT_PATTERNS = [`**/?(*.)+(spec|test).?([cm])[jt]s?(x)`] // do not tru
 const bundleOpts = { pure: true, bundle: true, esbuild: true, ts: 'auto' }
 const bareboneOpts = { ...bundleOpts, barebone: true }
 const hermesA = ['-w', '-Xmicrotask-queue'] // -Xes6-class fails with -O0 / -Og, --block-scoping fails in default, any of that is bad
+const hermesS = [...hermesA, '-Xes6-block-scoping']
 const denoA = ['run', '--allow-all'] // also will set DENO_COMPAT=1 env flag below
 const denoT = ['test', '--allow-all']
 const nodeTS = process.features.typescript ? 'auto' : 'flag'
@@ -42,6 +43,7 @@ const ENGINES = new Map(
     'v8:bundle': { binary: 'd8', binaryArgs: ['--expose-gc'], ...bareboneOpts },
     'jsc:bundle': { binary: 'jsc', target: 'safari13', ...bareboneOpts },
     'hermes:bundle': { binary: 'hermes', binaryArgs: hermesA, target: 'es2018', ...bareboneOpts },
+    'shermes:bundle': { binary: 'shermes', binaryArgs: hermesS, target: 'es2018', ...bareboneOpts },
     'spidermonkey:bundle': { binary: 'spidermonkey', ...bareboneOpts },
     'engine262:bundle': { binary: 'engine262', ...bareboneOpts },
     'quickjs:bundle': { binary: 'quickjs', binaryArgs: ['--std'], ...bareboneOpts },
@@ -62,7 +64,7 @@ const ENGINES = new Map(
     'msedge:playwright': { binary: 'msedge', browsers: 'playwright', ...bundleOpts },
   })
 )
-const barebonesOk = ['v8', 'd8', 'spidermonkey', 'quickjs', 'xs', 'hermes']
+const barebonesOk = ['v8', 'd8', 'spidermonkey', 'quickjs', 'xs', 'hermes', 'shermes']
 const barebonesUnhandled = ['jsc', 'escargot', 'boa', 'graaljs', 'jerry', 'engine262']
 
 const getEnvFlag = (name) => {
@@ -282,7 +284,7 @@ Object.assign(options, engineOptions)
 options.platform = options.binary // binary can be overriden by c8 or electron
 const isBrowserLike = options.browsers || options.electron
 setEnv('EXODUS_TEST_ENGINE', options.engine) // e.g. 'hermes:bundle', 'node:bundle', 'node:test', 'node:pure'
-setEnv('EXODUS_TEST_PLATFORM', options.binary) // e.g. 'hermes', 'node'
+setEnv('EXODUS_TEST_PLATFORM', options.binary === 'shermes' ? 'hermes' : options.binary) // e.g. 'hermes', 'node'
 setEnv('EXODUS_TEST_TIMEOUT', options.testTimeout)
 setEnv('EXODUS_TEST_DEVTOOLS', options.devtools ? '1' : '')
 setEnv('EXODUS_TEST_IS_BROWSER', isBrowserLike ? '1' : '')

bundler/bundle.js

@@ -498,6 +498,7 @@ export const build = async (...files) => {
     ],
   }
 
+  // eslint-disable-next-line unicorn/prefer-switch
   if (options.platform === 'hermes') {
     Object.assign(config.supported, {
       arrow: false,
@@ -506,6 +507,8 @@ export const build = async (...files) => {
       'const-and-let': false, // have to explicitly set for esbuild to not emit that in helpers, also to get a safeguard check
       'for-await': false,
     })
+  } else if (options.platform === 'shermes') {
+    Object.assign(config.supported, { 'async-generator': false, 'for-await': false })
   } else if (options.platform === 'jerryscript') {
     config.supported['class-private-field'] = false
     // config.minify = true // breaks on SyntaxError, FIXME

package.json

@@ -122,6 +122,7 @@
     "test:v8": "EXODUS_TEST_ENGINE=v8:bundle npm run test:_bundle --",
     "test:jsc": "EXODUS_TEST_ENGINE=jsc:bundle npm run test:_bundle --",
     "test:hermes": "EXODUS_TEST_ENGINE=hermes:bundle npm run test:_bundle --",
+    "test:shermes": "EXODUS_TEST_ENGINE=shermes:bundle npm run test:_bundle --",
     "test:spidermonkey": "EXODUS_TEST_ENGINE=spidermonkey:bundle npm run test:_bundle --",
     "test:engine262": "EXODUS_TEST_ENGINE=engine262:bundle npm run test:_bundle --",
     "test:quickjs": "EXODUS_TEST_ENGINE=quickjs:bundle npm run test:_bundle --",