refactor: cleanup compiler runtimes (#4230)

- Cleanup "tsCompilerOnMessage" by factoring out separate methods for each 
  request type:
    * "compile"
    * "runtimeCompile"
    * "runtimeTranspile"
- Simplify control flow of compiler workers by a) no longer calling "close()" in worker runtime after a
single message; b) explicitly shutting down worker from host after a single message

Co-authored-by: Ryan Dahl <ry@tinyclouds.org>

cli/compilers/ts.rs

@@ -620,11 +620,7 @@ async fn execute_in_thread(
     WorkerEvent::Message(buf) => Ok(buf),
     WorkerEvent::Error(error) => Err(error),
   }?;
-  // Compiler worker finishes after one request
-  // so we should receive signal that channel was closed.
-  // Then close worker's channel and join the thread.
-  let event = handle.get_event().await;
-  assert!(event.is_none());
+  // Shutdown worker and wait for thread to finish
   handle.sender.close_channel();
   join_handle.join().unwrap();
   Ok(buf)

cli/compilers/wasm.rs

@@ -134,11 +134,7 @@ async fn execute_in_thread(
     WorkerEvent::Message(buf) => Ok(buf),
     WorkerEvent::Error(error) => Err(error),
   }?;
-  // Compiler worker finishes after one request
-  // so we should receive signal that channel was closed.
-  // Then close worker's channel and join the thread.
-  let event = handle.get_event().await;
-  assert!(event.is_none());
+  // Shutdown worker and wait for thread to finish
   handle.sender.close_channel();
   join_handle.join().unwrap();
   Ok(buf)

cli/js/compiler.ts

@@ -36,7 +36,7 @@ import {
   WriteFileState,
   processConfigureResponse
 } from "./compiler_util.ts";
-import { Diagnostic } from "./diagnostics.ts";
+import { Diagnostic, DiagnosticItem } from "./diagnostics.ts";
 import { fromTypeScriptDiagnostic } from "./diagnostics_util.ts";
 import { assert } from "./util.ts";
 import * as util from "./util.ts";
@@ -81,25 +81,19 @@ interface CompileResult {
   diagnostics?: Diagnostic;
 }
 
-// TODO(bartlomieju): refactor this function into multiple functions
-// per CompilerRequestType
-async function tsCompilerOnMessage({
-  data: request
-}: {
-  data: CompilerRequest;
-}): Promise<void> {
-  switch (request.type) {
-    // `Compile` are requests from the internals to Deno, generated by both
-    // the `run` and `bundle` sub command.
-    case CompilerRequestType.Compile: {
-      const {
-        bundle,
-        config,
-        configPath,
-        outFile,
-        rootNames,
-        target
-      } = request;
+type RuntimeCompileResult = [
+  undefined | DiagnosticItem[],
+  Record<string, string>
+];
+
+type RuntimeBundleResult = [undefined | DiagnosticItem[], string];
+
+/** `Compile` are requests from the internals of Deno; eg. used when
+ * the `run` or `bundle` subcommand is used. */
+async function compile(
+  request: CompilerRequestCompile
+): Promise<CompileResult> {
+  const { bundle, config, configPath, outFile, rootNames, target } = request;
   util.log(">>> compile start", {
     rootNames,
     type: CompilerRequestType[request.type]
@@ -182,18 +176,26 @@ async function tsCompilerOnMessage({
       ? fromTypeScriptDiagnostic(diagnostics)
       : undefined
   };
-      globalThis.postMessage(result);
 
   util.log("<<< compile end", {
     rootNames,
     type: CompilerRequestType[request.type]
   });
-      break;
-    }
-    case CompilerRequestType.RuntimeCompile: {
-      // `RuntimeCompile` are requests from a runtime user, both compiles and
-      // bundles.  The process is similar to a request from the privileged
-      // side, but also returns the output to the on message.
+
+  return result;
+}
+
+/**`RuntimeCompile` are requests from a runtime user; it can be both
+ * "compile" and "bundle".
+ *
+ * The process is similar to a request from the privileged
+ * side, but unline `compile`, `runtimeCompile` allows to specify
+ * additional file mappings which can be used instead of relying
+ * on Deno defaults.
+ */
+async function runtimeCompile(
+  request: CompilerRequestRuntimeCompile
+): Promise<RuntimeCompileResult | RuntimeBundleResult> {
   const { rootName, sources, options, bundle, target } = request;
 
   util.log(">>> runtime compile start", {
@@ -204,9 +206,7 @@ async function tsCompilerOnMessage({
 
   // resolve the root name, if there are sources, the root name does not
   // get resolved
-      const resolvedRootName = sources
-        ? rootName
-        : resolveModules([rootName])[0];
+  const resolvedRootName = sources ? rootName : resolveModules([rootName])[0];
 
   // if there are options, convert them into TypeScript compiler options,
   // and resolve any external file references
@@ -293,13 +293,6 @@ async function tsCompilerOnMessage({
   const emitResult = program.emit();
 
   assert(emitResult.emitSkipped === false, "Unexpected skip of the emit.");
-      const result = [
-        diagnostics.length
-          ? fromTypeScriptDiagnostic(diagnostics).items
-          : undefined,
-        bundle ? state.emitBundle : state.emitMap
-      ];
-      globalThis.postMessage(result);
 
   assert(state.emitMap);
   util.log("<<< runtime compile finish", {
@@ -309,9 +302,20 @@ async function tsCompilerOnMessage({
     emitMap: Object.keys(state.emitMap)
   });
 
-      break;
+  const maybeDiagnostics = diagnostics.length
+    ? fromTypeScriptDiagnostic(diagnostics).items
+    : undefined;
+
+  if (bundle) {
+    return [maybeDiagnostics, state.emitBundle] as RuntimeBundleResult;
+  } else {
+    return [maybeDiagnostics, state.emitMap] as RuntimeCompileResult;
   }
-    case CompilerRequestType.RuntimeTranspile: {
+}
+
+async function runtimeTranspile(
+  request: CompilerRequestRuntimeTranspile
+): Promise<Record<string, TranspileOnlyResult>> {
   const result: Record<string, TranspileOnlyResult> = {};
   const { sources, options } = request;
   const compilerOptions = options
@@ -332,8 +336,32 @@ async function tsCompilerOnMessage({
     );
     result[fileName] = { source, map };
   }
-      globalThis.postMessage(result);
+  return result;
+}
 
+async function tsCompilerOnMessage({
+  data: request
+}: {
+  data: CompilerRequest;
+}): Promise<void> {
+  switch (request.type) {
+    case CompilerRequestType.Compile: {
+      const result = await compile(request as CompilerRequestCompile);
+      globalThis.postMessage(result);
+      break;
+    }
+    case CompilerRequestType.RuntimeCompile: {
+      const result = await runtimeCompile(
+        request as CompilerRequestRuntimeCompile
+      );
+      globalThis.postMessage(result);
+      break;
+    }
+    case CompilerRequestType.RuntimeTranspile: {
+      const result = await runtimeTranspile(
+        request as CompilerRequestRuntimeTranspile
+      );
+      globalThis.postMessage(result);
       break;
     }
     default:
@@ -343,9 +371,7 @@ async function tsCompilerOnMessage({
         } (${CompilerRequestType[(request as CompilerRequest).type]})`
       );
   }
-
-  // The compiler isolate exits after a single message.
-  globalThis.close();
+  // Currently Rust shuts down worker after single request
 }
 
 async function wasmCompilerOnMessage({
@@ -372,8 +398,7 @@ async function wasmCompilerOnMessage({
 
   util.log("<<< WASM compile end");
 
-  // The compiler isolate exits after a single message.
-  globalThis.close();
+  // Currently Rust shuts down worker after single request
 }
 
 function bootstrapTsCompilerRuntime(): void {