Deno.bundle supports targets < ES2017 (#6346)

This commit provides a "system_loader_es5.js" bundle loader which will be added
to the bundle when the target is < ES2017, which is the minimum target syntax
required for "system_loader.js".

Supports #5913 (via Deno.bundle()) with a couple caveats:

* Allowing "deno bundle" to take a different target is not supported, as we
specifically ignore "target" when passed in a TypeScript config file. This is
because deno bundle is really intended to generate bundles that work in Deno.
It is an unintentional side effect that some bundles are loadable in browsers.

* While a target of "es3" will be accepted, the module loader will still only be
compatible with ES5 or later. Realistically no one should be expecting bundles
generated by Deno to be used on IE8 and prior, and there is just too much
"baggage" to support that at this point.

This is a minor variation of 75bb9d, which exposed some sort of internal V8 bug.
Ref #6358

This is 100% authored by Kitson Kelly. Github might change the author when landing
so I'm leaving this in:
Co-authored-by: Kitson Kelly <me@kitsonkelly.com>

cli/js/compiler.ts

@@ -307,6 +307,10 @@ class Host implements ts.CompilerHost {
     }
   }
 
+  get options(): ts.CompilerOptions {
+    return this.#options;
+  }
+
   configure(
     cwd: string,
     path: string,
@@ -528,6 +532,7 @@ const _TS_SNAPSHOT_PROGRAM = ts.createProgram({
 
 // This function is called only during snapshotting process
 const SYSTEM_LOADER = getAsset("system_loader.js");
+const SYSTEM_LOADER_ES5 = getAsset("system_loader_es5.js");
 
 function buildLocalSourceFileCache(
   sourceFileMap: Record<string, SourceFileMapEntry>
@@ -683,7 +688,12 @@ function createBundleWriteFile(state: WriteFileState): WriteFileCallback {
     assert(state.bundle);
     // we only support single root names for bundles
     assert(state.rootNames.length === 1);
-    state.bundleOutput = buildBundle(state.rootNames[0], data, sourceFiles);
+    state.bundleOutput = buildBundle(
+      state.rootNames[0],
+      data,
+      sourceFiles,
+      state.host.options.target ?? ts.ScriptTarget.ESNext
+    );
   };
 }
 
@@ -949,7 +959,8 @@ function normalizeUrl(rootName: string): string {
 function buildBundle(
   rootName: string,
   data: string,
-  sourceFiles: readonly ts.SourceFile[]
+  sourceFiles: readonly ts.SourceFile[],
+  target: ts.ScriptTarget
 ): string {
   // when outputting to AMD and a single outfile, TypeScript makes up the module
   // specifiers which are used to define the modules, and doesn't expose them
@@ -967,8 +978,8 @@ function buildBundle(
   let instantiate: string;
   if (rootExports && rootExports.length) {
     instantiate = hasTla
-      ? `const __exp = await __instantiateAsync("${rootName}");\n`
+      ? `const __exp = await __instantiate("${rootName}", true);\n`
-      : `const __exp = __instantiate("${rootName}");\n`;
+      : `const __exp = __instantiate("${rootName}", false);\n`;
     for (const rootExport of rootExports) {
       if (rootExport === "default") {
         instantiate += `export default __exp["${rootExport}"];\n`;
@@ -978,10 +989,19 @@ function buildBundle(
     }
   } else {
     instantiate = hasTla
-      ? `await __instantiateAsync("${rootName}");\n`
+      ? `await __instantiate("${rootName}", true);\n`
-      : `__instantiate("${rootName}");\n`;
+      : `__instantiate("${rootName}", false);\n`;
   }
-  return `${SYSTEM_LOADER}\n${data}\n${instantiate}`;
+  const es5Bundle =
+    target === ts.ScriptTarget.ES3 ||
+    target === ts.ScriptTarget.ES5 ||
+    target === ts.ScriptTarget.ES2015 ||
+    target === ts.ScriptTarget.ES2016
+      ? true
+      : false;
+  return `${
+    es5Bundle ? SYSTEM_LOADER_ES5 : SYSTEM_LOADER
+  }\n${data}\n${instantiate}`;
 }
 
 function setRootExports(program: ts.Program, rootModule: string): void {

cli/tests/bundle.test.out

@@ -1,6 +1,5 @@
 [WILDCARD]
-let System, __instantiateAsync, __instantiate;
+let System, __instantiate;
-[WILDCARD]
 (() => {
 [WILDCARD]
 })();
@@ -15,7 +14,7 @@ System.register("mod1", ["subdir2/mod2"], function (exports_3, context_3) {
 [WILDCARD]
 });
 
-const __exp = __instantiate("mod1");
+const __exp = __instantiate("mod1", false);
 export const returnsHi = __exp["returnsHi"];
 export const returnsFoo2 = __exp["returnsFoo2"];
 export const printHello3 = __exp["printHello3"];

cli/tests/compiler_api_test.ts

@@ -1,7 +1,9 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 import { assert, assertEquals } from "../../std/testing/asserts.ts";
 
-Deno.test("compilerApiCompileSources", async function () {
+Deno.test({
+  name: "Deno.compile() - sources provided",
+  async fn() {
     const [diagnostics, actual] = await Deno.compile("/foo.ts", {
       "/foo.ts": `import * as bar from "./bar.ts";\n\nconsole.log(bar);\n`,
       "/bar.ts": `export const bar = "bar";\n`,
@@ -14,9 +16,12 @@ Deno.test("compilerApiCompileSources", async function () {
       "/foo.js.map",
       "/foo.js",
     ]);
+  },
 });
 
-Deno.test("compilerApiCompileNoSources", async function () {
+Deno.test({
+  name: "Deno.compile() - no sources provided",
+  async fn() {
     const [diagnostics, actual] = await Deno.compile("./subdir/mod1.ts");
     assert(diagnostics == null);
     assert(actual);
@@ -24,9 +29,12 @@ Deno.test("compilerApiCompileNoSources", async function () {
     assertEquals(keys.length, 6);
     assert(keys[0].endsWith("print_hello.js.map"));
     assert(keys[1].endsWith("print_hello.js"));
+  },
 });
 
-Deno.test("compilerApiCompileOptions", async function () {
+Deno.test({
+  name: "Deno.compile() - compiler options effects imit",
+  async fn() {
     const [diagnostics, actual] = await Deno.compile(
       "/foo.ts",
       {
@@ -41,9 +49,12 @@ Deno.test("compilerApiCompileOptions", async function () {
     assert(actual);
     assertEquals(Object.keys(actual), ["/foo.js"]);
     assert(actual["/foo.js"].startsWith("define("));
+  },
 });
 
-Deno.test("compilerApiCompileLib", async function () {
+Deno.test({
+  name: "Deno.compile() - pass lib in compiler options",
+  async fn() {
     const [diagnostics, actual] = await Deno.compile(
       "/foo.ts",
       {
@@ -57,9 +68,12 @@ Deno.test("compilerApiCompileLib", async function () {
     assert(diagnostics == null);
     assert(actual);
     assertEquals(Object.keys(actual), ["/foo.js.map", "/foo.js"]);
+  },
 });
 
-Deno.test("compilerApiCompileTypes", async function () {
+Deno.test({
+  name: "Deno.compile() - properly handles .d.ts files",
+  async fn() {
     const [diagnostics, actual] = await Deno.compile(
       "/foo.ts",
       {
@@ -72,9 +86,12 @@ Deno.test("compilerApiCompileTypes", async function () {
     assert(diagnostics == null);
     assert(actual);
     assertEquals(Object.keys(actual), ["/foo.js.map", "/foo.js"]);
+  },
 });
 
-Deno.test("transpileOnlyApi", async function () {
+Deno.test({
+  name: "Deno.transpileOnly()",
+  async fn() {
     const actual = await Deno.transpileOnly({
       "foo.ts": `export enum Foo { Foo, Bar, Baz };\n`,
     });
@@ -82,9 +99,12 @@ Deno.test("transpileOnlyApi", async function () {
     assertEquals(Object.keys(actual), ["foo.ts"]);
     assert(actual["foo.ts"].source.startsWith("export var Foo;"));
     assert(actual["foo.ts"].map);
+  },
 });
 
-Deno.test("transpileOnlyApiConfig", async function () {
+Deno.test({
+  name: "Deno.transpileOnly() - config effects commit",
+  async fn() {
     const actual = await Deno.transpileOnly(
       {
         "foo.ts": `export enum Foo { Foo, Bar, Baz };\n`,
@@ -98,26 +118,35 @@ Deno.test("transpileOnlyApiConfig", async function () {
     assertEquals(Object.keys(actual), ["foo.ts"]);
     assert(actual["foo.ts"].source.startsWith("define("));
     assert(actual["foo.ts"].map == null);
+  },
 });
 
-Deno.test("bundleApiSources", async function () {
+Deno.test({
+  name: "Deno.bundle() - sources passed",
+  async fn() {
     const [diagnostics, actual] = await Deno.bundle("/foo.ts", {
       "/foo.ts": `export * from "./bar.ts";\n`,
       "/bar.ts": `export const bar = "bar";\n`,
     });
     assert(diagnostics == null);
-  assert(actual.includes(`__instantiate("foo")`));
+    assert(actual.includes(`__instantiate("foo", false)`));
     assert(actual.includes(`__exp["bar"]`));
+  },
 });
 
-Deno.test("bundleApiNoSources", async function () {
+Deno.test({
+  name: "Deno.bundle() - no sources passed",
+  async fn() {
     const [diagnostics, actual] = await Deno.bundle("./subdir/mod1.ts");
     assert(diagnostics == null);
-  assert(actual.includes(`__instantiate("mod1")`));
+    assert(actual.includes(`__instantiate("mod1", false)`));
     assert(actual.includes(`__exp["printHello3"]`));
+  },
 });
 
-Deno.test("bundleApiConfig", async function () {
+Deno.test({
+  name: "Deno.bundle() - compiler config effects emit",
+  async fn() {
     const [diagnostics, actual] = await Deno.bundle(
       "/foo.ts",
       {
@@ -130,21 +159,43 @@ Deno.test("bundleApiConfig", async function () {
     );
     assert(diagnostics == null);
     assert(!actual.includes(`random`));
+  },
 });
 
-Deno.test("bundleApiJsModules", async function () {
+Deno.test({
+  name: "Deno.bundle() - JS Modules included",
+  async fn() {
     const [diagnostics, actual] = await Deno.bundle("/foo.js", {
       "/foo.js": `export * from "./bar.js";\n`,
       "/bar.js": `export const bar = "bar";\n`,
     });
     assert(diagnostics == null);
     assert(actual.includes(`System.register("bar",`));
+  },
 });
 
-Deno.test("diagnosticsTest", async function () {
+Deno.test({
+  name: "Deno.bundle - pre ES2017 uses ES5 loader",
+  async fn() {
+    const [diagnostics, actual] = await Deno.bundle(
+      "/foo.ts",
+      {
+        "/foo.ts": `console.log("hello world!")\n`,
+      },
+      { target: "es2015" }
+    );
+    assert(diagnostics == null);
+    assert(actual.includes(`var __awaiter = `));
+  },
+});
+
+Deno.test({
+  name: "runtime compiler APIs diagnostics",
+  async fn() {
     const [diagnostics] = await Deno.compile("/foo.ts", {
       "/foo.ts": `document.getElementById("foo");`,
     });
     assert(Array.isArray(diagnostics));
     assert(diagnostics.length === 1);
+  },
 });

deno_typescript/README.md

@@ -69,9 +69,14 @@ At the time of this writing, while V8 and other JavaScript engines have
 implemented top-level-await, no browsers have it implemented, meaning that most
 browsers could not consume modules that require top-level-await.
 
-In order to facilitate this, there are two functions that are in the scope of
+In order to allow more browsers to consume bundles, there is an argument that is
-the module in addition to the `System.register()` method. `__instantiate(main)`
+passed to the `__instantiate()` function which determines if the code is
-will bootstrap everything synchronously and `__instantiateAsync(main)` will do
+bootstrapped asynchronously or not. When emitting a bundle that contains a
-so asynchronously. When emitting a bundle that contains a module that requires
+module that requires top-level-await, Deno will detect this and utilise
-top-level-await, Deno will detect this and utilise
+`await __instantiate(main, true)`.
-`await __instantiateAsync(main)` instead.
+
+The `system_loader_es5.js` is a transpiled version of `system_loader.js` that is
+designed to work with ES5 or later, and will be used when the bundle target is <
+ES2017. While ES3 is still a potential target which can be passed in a
+`tsconfig.json` to Deno, any resulting bundle will not be compatible, as there
+is a need to utilise items like `Object.defineProperty()`.

deno_typescript/lib.rs

@@ -208,7 +208,7 @@ pub fn mksnapshot_bundle(
   js_check(
     isolate.execute(&bundle_filename.to_string_lossy(), bundle_source_code),
   );
-  let script = &format!("__instantiate(\"{}\");", main_module_name);
+  let script = &format!("__instantiate(\"{}\", false);", main_module_name);
   js_check(isolate.execute("anon", script));
   write_snapshot(isolate, snapshot_filename)?;
   Ok(())
@@ -252,6 +252,7 @@ pub fn get_asset(name: &str) -> Option<&'static str> {
   }
   match name {
     "system_loader.js" => Some(include_str!("system_loader.js")),
+    "system_loader_es5.js" => Some(include_str!("system_loader_es5.js")),
     "bootstrap.ts" => Some("console.log(\"hello deno\");"),
     "typescript.d.ts" => inc!("typescript.d.ts"),
     "lib.dom.d.ts" => inc!("lib.dom.d.ts"),

deno_typescript/system_loader.js

@@ -6,8 +6,7 @@
 
 // @ts-nocheck
 /* eslint-disable */
-let System, __instantiateAsync, __instantiate;
+let System, __instantiate;
-
 (() => {
   const r = new Map();
 
@@ -16,7 +15,6 @@ let System, __instantiateAsync, __instantiate;
       r.set(id, { d, f, exp: {} });
     },
   };
-
   async function dI(mid, src) {
     let id = mid.replace(/\.\w+$/i, "");
     if (id.includes("./")) {
@@ -93,16 +91,9 @@ let System, __instantiateAsync, __instantiate;
     }
     return m.exp;
   }
-
+  __instantiate = (m, a) => {
-  __instantiateAsync = async (m) => {
+    System = __instantiate = undefined;
-    System = __instantiateAsync = __instantiate = undefined;
     rF(m);
-    return gExpA(m);
+    return a ? gExpA(m) : gExp(m);
-  };
-
-  __instantiate = (m) => {
-    System = __instantiateAsync = __instantiate = undefined;
-    rF(m);
-    return gExp(m);
   };
 })();

deno_typescript/system_loader_es5.js

@@ -0,0 +1,182 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+// This is a specialised implementation of a System module loader.
+
+"use strict";
+
+// @ts-nocheck
+/* eslint-disable */
+var System, __instantiate;
+(function () {
+  // prettier-ignore
+  var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+  };
+  // prettier-ignore
+  var __generator = (this && this.__generator) || function (thisArg, body) {
+    var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
+    return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
+    function verb(n) { return function (v) { return step([n, v]); }; }
+    function step(op) {
+        if (f) throw new TypeError("Generator is already executing.");
+        while (_) try {
+            if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
+            if (y = 0, t) op = [op[0] & 2, t.value];
+            switch (op[0]) {
+                case 0: case 1: t = op; break;
+                case 4: _.label++; return { value: op[1], done: false };
+                case 5: _.label++; y = op[1]; op = [0]; continue;
+                case 7: op = _.ops.pop(); _.trys.pop(); continue;
+                default:
+                    if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
+                    if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
+                    if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
+                    if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
+                    if (t[2]) _.ops.pop();
+                    _.trys.pop(); continue;
+            }
+            op = body.call(thisArg, _);
+        } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
+        if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
+    }
+  };
+  var r = Object.create(null);
+  System = {
+    register: function (id, d, f) {
+      r[id] = { d: d, f: f, exp: {} };
+    },
+  };
+  function dI(mid, src) {
+    return __awaiter(this, void 0, void 0, function () {
+      var id, _a, o, ia, _b, sa, oa, s, i;
+      return __generator(this, function (_c) {
+        id = mid.replace(/\.\w+$/i, "");
+        if (id.includes("./")) {
+          (_a = id.split("/").reverse()),
+            (o = _a[0]),
+            (ia = _a.slice(1)),
+            (_b = src.split("/").reverse()),
+            (sa = _b.slice(1)),
+            (oa = [o]);
+          (s = 0), (i = void 0);
+          while ((i = ia.shift())) {
+            if (i === "..") s++;
+            else if (i === ".") break;
+            else oa.push(i);
+          }
+          if (s < sa.length) oa.push.apply(oa, sa.slice(s));
+          id = oa.reverse().join("/");
+        }
+        return [
+          2,
+          id in r
+            ? gExpA(id)
+            : Promise.resolve().then(function () {
+                return require(mid);
+              }),
+        ];
+      });
+    });
+  }
+  function gC(id, main) {
+    return {
+      id: id,
+      import: function (m) {
+        return dI(m, id);
+      },
+      meta: { url: id, main: main },
+    };
+  }
+  function gE(exp) {
+    return function (id, v) {
+      var _a;
+      v = typeof id === "string" ? ((_a = {}), (_a[id] = v), _a) : id;
+      for (var _i = 0, _b = Object.entries(v); _i < _b.length; _i++) {
+        var _c = _b[_i],
+          id_1 = _c[0],
+          value = _c[1];
+        Object.defineProperty(exp, id_1, {
+          value: value,
+          writable: true,
+          enumerable: true,
+        });
+      }
+    };
+  }
+  function rF(main) {
+    var m;
+    for (var id in r) {
+      m = r[id];
+      var f = m.f,
+        exp = m.exp;
+      var _a = f(gE(exp), gC(id, id === main)),
+        e = _a.execute,
+        s = _a.setters;
+      delete m.f;
+      m.e = e;
+      m.s = s;
+    }
+  }
+  function gExpA(id) {
+    return __awaiter(this, void 0, void 0, function () {
+      var m, d, e, s, i, _a, _b, r_1;
+      return __generator(this, function (_c) {
+        switch (_c.label) {
+          case 0:
+            if (!(id in r)) return [2];
+            m = r[id];
+            if (!m.s) return [3, 6];
+            (d = m.d), (e = m.e), (s = m.s);
+            delete m.s;
+            delete m.e;
+            i = 0;
+            _c.label = 1;
+          case 1:
+            if (!(i < s.length)) return [3, 4];
+            _b = (_a = s)[i];
+            return [4, gExpA(d[i])];
+          case 2:
+            _b.apply(_a, [_c.sent()]);
+            _c.label = 3;
+          case 3:
+            i++;
+            return [3, 1];
+          case 4:
+            r_1 = e();
+            if (!r_1) return [3, 6];
+            return [4, r_1];
+          case 5:
+            _c.sent();
+            _c.label = 6;
+          case 6:
+            return [2, m.exp];
+        }
+      });
+    });
+  }
+  function gExp(id) {
+    if (!(id in r)) return;
+    var m = r[id];
+    if (m.s) {
+      var d = m.d,
+        e = m.e,
+        s = m.s;
+      delete m.s;
+      delete m.e;
+      for (var i = 0; i < s.length; i++) s[i](gExp(d[i]));
+      e();
+    }
+    return m.exp;
+  }
+  __instantiate = function (m, a) {
+    System = __instantiate = undefined;
+    rF(m);
+    return a ? gExpA(m) : gExp(m);
+  };
+})();