1 files changed, 124 insertions, 0 deletions
diff --git a/deno_typescript/bundle_loader.js b/deno_typescript/bundle_loader.js
new file mode 100644
index 000000000..682754628
--- /dev/null
+++ b/deno_typescript/bundle_loader.js
@@ -0,0 +1,124 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+
+// A script preamble that provides the ability to load a single outfile
+// TypeScript "bundle" where a main module is loaded which recursively
+// instantiates all the other modules in the bundle.  This code is used to load
+// bundles when creating snapshots, but is also used when emitting bundles from
+// Deno cli.
+
+/**
+ * @type {(name: string, deps: ReadonlyArray<string>, factory: (...deps: any[]) => void) => void}
+ */
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+let define;
+
+/**
+ * @type {(mod: string | string[]) => void}
+ */
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+let instantiate;
+
+/**
+ * @callback Factory
+ * @argument {...any[]} args
+ * @returns {object | void}
+ */
+
+/**
+ * @typedef ModuleMetaData
+ * @property {ReadonlyArray<string>} dependencies
+ * @property {(Factory | object)=} factory
+ * @property {object} exports
+ */
+
+(function() {
+  /**
+   * @type {Map<string, ModuleMetaData>}
+   */
+  const modules = new Map();
+
+  /**
+   * Bundles in theory can support "dynamic" imports, but for internal bundles
+   * we can't go outside to fetch any modules that haven't been statically
+   * defined.
+   * @param {string[]} deps
+   * @param {(...deps: any[]) => void} resolve
+   * @param {(err: any) => void} reject
+   */
+  const require = (deps, resolve, reject) => {
+    try {
+      if (deps.length !== 1) {
+        throw new TypeError("Expected only a single module specifier.");
+      }
+      if (!modules.has(deps[0])) {
+        throw new RangeError(`Module "${deps[0]}" not defined.`);
+      }
+      resolve(getExports(deps[0]));
+    } catch (e) {
+      if (reject) {
+        reject(e);
+      } else {
+        throw e;
+      }
+    }
+  };
+
+  define = (id, dependencies, factory) => {
+    if (modules.has(id)) {
+      throw new RangeError(`Module "${id}" has already been defined.`);
+    }
+    modules.set(id, {
+      dependencies,
+      factory,
+      exports: {}
+    });
+  };
+
+  /**
+   * @param {string} id
+   * @returns {any}
+   */
+  function getExports(id) {
+    const module = modules.get(id);
+    if (!module) {
+      // because `$deno$/ts_global.d.ts` looks like a real script, it doesn't
+      // get erased from output as an import, but it doesn't get defined, so
+      // we don't have a cache for it, so because this is an internal bundle
+      // we can just safely return an empty object literal.
+      return {};
+    }
+    if (!module.factory) {
+      return module.exports;
+    } else if (module.factory) {
+      const { factory, exports } = module;
+      delete module.factory;
+      if (typeof factory === "function") {
+        const dependencies = module.dependencies.map(id => {
+          if (id === "require") {
+            return require;
+          } else if (id === "exports") {
+            return exports;
+          }
+          return getExports(id);
+        });
+        factory(...dependencies);
+      } else {
+        Object.assign(exports, factory);
+      }
+      return exports;
+    }
+  }
+
+  instantiate = dep => {
+    define = undefined;
+    if (Array.isArray(dep)) {
+      for (const d of dep) {
+        getExports(d);
+      }
+    } else {
+      getExports(dep);
+    }
+    // clean up, or otherwise these end up in the runtime environment
+    instantiate = undefined;
+  };
+})();