Bundles can be sync or async based on top level await (#4124)

Previously, bundles always utilised top level await, even if the bundled
modules didn't require top level await.  Now, analysis of the bundle is
done and if none of the bundled modules are asynchronously executed,
then the bundle as a whole will be synchronously executed.

Fixes #4055
Fixes #4123

1 files changed, 43 insertions, 29 deletions

diff --git a/deno_typescript/system_loader.js b/deno_typescript/system_loader.js
index c1365f6c8..18a08107e 100644
--- a/deno_typescript/system_loader.js
+++ b/deno_typescript/system_loader.js
@@ -2,20 +2,16 @@
 
 // This is a specialised implementation of a System module loader.
 
-// eslint-disable-next-line @typescript-eslint/no-unused-vars
-let System;
-let __inst;
+// @ts-nocheck
+/* eslint-disable */
+
+let System, __inst, __inst_s;
 
 (() => {
   const mMap = new Map();
   System = {
-    register(id, deps, f) {
-      mMap.set(id, {
-        id,
-        deps,
-        f,
-        exp: {}
-      });
+    register(id, d, f) {
+      mMap.set(id, { id, d, f, exp: {} });
     }
   };
 
@@ -28,11 +24,10 @@ let __inst;
     };
   };
 
-  const gE = data => {
-    const { exp } = data;
-    return (id, value) => {
-      const values = typeof id === "string" ? { [id]: value } : id;
-      for (const [id, value] of Object.entries(values)) {
+  const gE = ({ exp }) => {
+    return (id, v) => {
+      const vs = typeof id === "string" ? { [id]: v } : id;
+      for (const [id, value] of Object.entries(vs)) {
         Object.defineProperty(exp, id, {
           value,
           writable: true,
@@ -47,39 +42,58 @@ let __inst;
   const enq = ids => {
     for (const id of ids) {
       if (!iQ.includes(id)) {
-        const { deps } = mMap.get(id);
+        const { d } = mMap.get(id);
         iQ.push(id);
-        enq(deps);
+        enq(d);
       }
     }
   };
 
-  const dr = async main => {
+  const gRQ = main => {
     const rQ = [];
     let id;
     while ((id = iQ.pop())) {
-      const m = mMap.get(id);
-      const { f } = m;
-      if (!f) {
-        return;
-      }
-      rQ.push([m.deps, f(gE(m), gC(m, id === main))]);
-      m.f = undefined;
+      const m = mMap.get(id),
+        { f } = m;
+      if (!f) return;
+      rQ.push([m.d, f(gE(m), gC(m, id === main))]);
+      delete m.f;
     }
+    return rQ;
+  };
+
+  const dr = async main => {
+    const rQ = gRQ(main);
     let r;
     while ((r = rQ.shift())) {
-      const [deps, { execute, setters }] = r;
-      for (let i = 0; i < deps.length; i++) setters[i](mMap.get(deps[i])?.exp);
+      const [d, { execute, setters }] = r;
+      for (let i = 0; i < d.length; i++) setters[i](mMap.get(d[i])?.exp);
       const e = execute();
       if (e) await e;
     }
   };
 
+  const dr_s = main => {
+    const rQ = gRQ(main);
+    let r;
+    while ((r = rQ.shift())) {
+      const [d, { execute, setters }] = r;
+      for (let i = 0; i < d.length; i++) setters[i](mMap.get(d[i])?.exp);
+      execute();
+    }
+  };
+
   __inst = async id => {
-    System = undefined;
-    __inst = undefined;
+    System = __inst = __inst_s = undefined;
     enq([id]);
     await dr(id);
     return mMap.get(id)?.exp;
   };
+
+  __inst_s = id => {
+    System = __inst = __inst_s = undefined;
+    enq([id]);
+    dr_s(id);
+    return mMap.get(id)?.exp;
+  };
 })();